Chronic Conditions Prevention and Management Assignment - 1

Chronic Conditions Prevention and Management - Assignment Example Secondly, cancer has many causative agents which include viruses like the human papilloma virus, radiations, and unprotected sex among other factors. Cancer has a long latency period implying that it can take along period before the effects are seen. Latency period depends on factors like degree of exposure to the risk, causative agent and immune competency of an individual and the site of inoculation of the causative agent (Pories, Moses and Lotz, 2009) Cancer is a disease known to affect all segments of the Australian population. However, the older people are primary the biggest victims. As such, the framework targets people aged between 50 years and 70 years. Greene & Heniford (2010) state that incidents of cancer increase exponentially with advancement in age. It is for this reason that different scholars like McVie (2006) and Pories, Moses & Lotz (2009) have come up with studies that are focused on mitigating the effects of the disease among the elderly. Members of the targeted population are not only at higher risk of contracting the disease but also face various challenges in recovery from the condition. When determining the treatment procedures for the group, care givers are always required to focus on the overall health of the individuals in question as well as their ability to keep up with their family activities. Different sets of conditions influence how the people aged between 50 and 75 cope with cancer. Most of the sta ccatos are related to their physical health. Age is not only a cancer risk factor but also an aspect that influences the probability of suffering from other related conditions and injuries. The aging process among this target population is a very complex issue. Foot & Sanson-Fisher (2005) notes that the actual age and the physical wellbeing of the members of this sample affects how they respond to cancer and their mental wellbeing. The other major characteristic of this group is their physical ability to respond to the

Trace the historical deveopment of payment systems from cash to Research Paper

Trace the historical deveopment of payment systems from cash to negotiable instruments to electonic funds transfer and debit cards - Research Paper Example s related to payment systems for the business transactions (Economy Watch, â€Å"Global Economy†) In this regard, organizations and inhabitants are able to undertake the operations nationally as well as in a global context with better efficiency and effectiveness. The transactions include transfer of goods and/or services, investment and fund among others. Thus, in the modern day context numerous transactions take place on a daily basis. These transactions deal with acquisition of financial assets, goods and other services. In this regards, a well defined payment system significantly aids to recognize as an important function in order to eliminate the fictions in the trading environment (BSP, â€Å"What is a payment system?†). Payment system comprises of various instruments, banking procedures along with the interbank transfer of funds to regulate the transfer of funds both nationally and internationally environment. Banking transaction between the parties is an important medium in the developed economy for making payments. Besides, the payment system is an important part of the economic and financial infrastructure. The effective functioning of the payment system enables the transaction to be completed safely and within the time. Moreover, the payment system is highly affected due to the high exposure of risk to the parties to the contract. Thus, the consideration of the proper security measure in order to control the feature of payment system is also very important to mitigate the risk related to it (CPSS 431-449) Correspondingly, the payment system allows the buyers and sellers to complete the transaction in very safe and timely manner in electronic forms. In this regard, it can also be affirmed that t he payment system is the key determinant of financial markets to settle the trading agreements that include government securities, stocks, foreign exchange, commercial paper and bonds among others. Likewise, there are various risks attached to the payment system

Characters from Alice Hoffman's Saint Helene Essay

Characters from Alice Hoffman's Saint Helene - Essay Example The main character of the novel is Saint Helene though of course. The characters are set in the era of candles and lights made out of paper bags, sand and candles. Helena’s mother takes the authority in the house of replacing every melting pot of white wax with fresh candles. However it is shown in the beginning that Helene’s indifferent to her surroundings. Helene went to a high school called Middleborough High till her junior year. She was known to be a quiet recluse girl who had been dejected by the people around. Her companionship was very little. She was barely known her school. Whatever little was she known, she was known as someone who would spend her entire afternoon in a cafeteria filling paper pages. That was all people knew about her. The whole school used to look down upon her. The girls around her used to thank their stars that they are not Helen. That is the kind aura with which Alice Hoffman has set the character of the book in the beginning of the novel. To many she is unrelatable. She is not your routine girl. She hardly cares about her exterior and how she appears to the outside world. She is known to be fat, ugly, sorrowful . she has no friends. People think she is lost in her own world and the girls in her school find relief in the fact that they are not HER. ... However, she is a strong person from within. She puts a tough fight against the insulting connotations sent her way by her peers and school people. (Hoffman) As the story progresses her character is shown to evolve. Slowly and gradually she is redeemed in her eyes and in the eyes of people around her. She gains confidence, holds her ground and starts becoming more viable and acceptable by the society that was around her. The evolution in the character was phenomenal. It’s the best character in the book and makes inroads into this world without having the most appealing features or the most charismatic habits. She is by far the best character that this story has to offer. Bibliography Hoffman, Alice. Saint Helene.

Humanities II course work Essay Example | Topics and Well Written Essays - 2750 words

Humanities II course work - Essay Example As the movement grew, it gave rise to expressions of the fantastic and the exotic (Cunningham & Reich, 459). While Romanticism can be a nebulous concept, it’s most accurately expressed through a core group of elements in art and in literature. One of its earliest manifestations was a love of nature, expressed by artists throughout Europe, who exhibited an unprecedented use of personal perspective, scope and color. This was, in large part, a reaction against the onset of modern society. â€Å"The growing industrialization of life in the great cities, and the effect of inventions like the railway train on urban architecture stimulated a ‘back-to-nature’ movement as Romanticism provided an escape from the grim realities of urbanization and industrialization† (Cunningham & Reich, 430). This style struck a chord with people who were, in their own ways, seeking an escape from the de-personalizing effects of society. As the Romantic style gained momentum in the la te 18th and early 19th centuries, it became more self-consciously a rejection of classical art forms. The American and French revolutions utilized classical forms to express their rejections of the old forms of government Romanticism to Post-Modernism 3 against which they were rebelling (Cunningham and Reich, 424). The leaders of America’s revolution against Great Britain borrowed heavily from classical forms of architecture to express a timeless connection between their Democratic form of government and that of the ancients Greeks and Romans. For Romantic artists, this was a limiting artistic convention not adapted to the kind of self-expression with which the new style was infused. In the early phase of the Romantic movement, Goethe’s plays served as a literary catalyst for the turbulent, aggressive Sturm und Drang school. His works were prototypes of the emotionalism and rejection of governmental authority that characterized Romanticism. â€Å"Modern criticism stil l considers Goethe’s use of dramatic technique in the Sturm und Drang as unconventional and revolutionary with respect to dramatic forms in general and Aristotelian drama in particular† (Stewart, 277). This trend would come to encompass music, poetry and the philosophy of Emmanuel Kant, Georg Hegel and Arthur Schopenhauer. The political environment in Europe at the time was set in turmoil by the French revolution and its aftermath. The Napoleonic wars of the late 18th and early 19 centuries aggravated nationalistic fervor throughout the continent. This historic and political cataclysm had a profound influence on artists and thinkers. Romanticism lent itself readily to mythological themes, and the great life-and-death struggle that engulfed Europe inflamed the mythologies and folk traditions in every European nation. In Germany, for instance, this phenomenon found its apex in the ancient Norse mythology that Richard Wagner would fashion into his famous Ring cycle opera. The lasting impact of Romanticism was that the nationalism of Europe’s nation Romanticism to Post-Modernism 4 states was enhanced - in some cases created - by the writers and artists of the Romantic movement. â€Å"Many Romantic artists identified with the nationalist movements of the times and either supported their own country’s fight for freedom (as in the case of Verdi) or championed the cause of others (as did Lord Byron)†

Religion, Media and Ethics Essay Example | Topics and Well Written Essays - 500 words

Religion, Media and Ethics - Essay Example Media ethics as such is a complex subject, as it is formulated on the basis of the concurrent culture, economy and national policies. It has been observed by a number of researchers that the media symbolizes societal values. Slinger (1983) has mentioned a number of examples in which media comes up with advertisements which prompts the views to connect the product being advertised to societal values specific to the viewers. One important value that a person relates to is his personal beliefs and religious beliefs. It’s generally considered that the popular programs in the secular media do not have religious intentions. Considering the recent development of secularizing of religious broadcasting sponsored by religious organizations, the identification of religiously persuading content becomes difficult. Programs and specifically labeled content dealt by religious media are the ones which are bracketed as of the ones which influence the public religiously. However, there are arguments that this is not the case. Mark Pinsky (2001, p.5) observes that he ‘found God, faith and spirituality in abundance on Th e Simpsons’.Jana Reiss (2004, p.xii) claims that Buffy the Vampire Slayer and its spin-off Angel ‘are two of the most religious programs on network TV’. These arguments suggest that cartoon programs and other popular programs may also be considered as religious. I agree with this argument. The earlier argument that only religious media can contain religious content is based on the assumption that religion is associated with religious institutions and organizations. Schultze (1990) has argued that being religious does not mean belonging to a religion but it’s a way of life with its own world view. Anything which would influence this world view thus must be considered religious persuasion. Thus there is no wonder in Pinsky finding spirituality and god in the cartoon

Electronic Frontiers Australia Essay Example for Free

Electronic Frontiers Australia Essay This paper is meant to analyze the role evaluation in media relations campaigns. It is an evaluation of media campaign with specific focus on the campaign done by Electronic Frontiers Australia (EFA), an Australia-based NGO working on the online liberties and rights of all Internet users. Its campaign is entitled â€Å"Generation Z†, that is teenagers between the ages of thirteen and eighteen years. The campaign’s overall intention is to create an impression of personal responsibility among members of the target group by inculcating a sense of discipline. It is also meant to inform Generation Z about the disadvantages of irresponsible use of the internet then inverse their awareness in utilizing Internet content. In order to achieve the campaign objective, it is necessary to involve parents in the process. Parents need to be involved in the process of monitoring their children’s internet use and also by teaching them how to use the internet in the most appropriate way. The campaign aims at creating appropriate communication channels for this target population so that they can adequately develop desirable internet communication plans of action. This campaign will be an opposition to government policy because it will be different from that of the government policy which advocates for internet control through external rather than internal mechanisms. Communication practitioners focus a great deal on the best ways to deliver communication strategies that are able to bring about wider awareness of the clients that they serve. Need for public relation services by the industry means that these public relation firms are always evaluating their approaches towards communication strategies that are prescribed for the industry. Crystal (2003) argues that, â€Å"Public relations provide a service for an organization by helping it provide clients better information of their functions. † Within organizations, public relations can also be viewed from the perspective of Public Information or Customer Relations (Paul 2008), â€Å"these departments help clients in answering queries, complaints, or problems that might arise in their relationship with the organization. They are usually the most helpful departments, as they exist to show the organization at their best. † The EFA campaign will use a comprehensive method and strategy to ensure success of the campaign. This will be achieved through public relations and media relations principles. Good media relations will be build through gaining appropriate insight of the media by devising ways through which appropriate relationships can be build. Furthermore, the firm has relevant information regarding internet filtering accessed through substantive internet user support from the public; hence this will be a big advantage to the campaign. Use of persuasive theories will also offer the much needed support and attention to the campaign. Generally, evaluation can be seen as the systematic application of research methods, to understand the effectiveness and usefulness of interventions. Evaluation determines the effectiveness of a programme in terms achieving goals that have been set up and the effectiveness of those goals. Evaluation therefore is a means of measurement that is meant to assess the level of success of a communication strategy. Evaluation determines the level to which a campaign has reached its goals and also helps organizations and individuals to understand how a particular campaign worked, it is therefore a tool for determining success of interventions towards a particular campaign. Evaluation should â€Å"specify explicitly the goals and objectives,† (Ronald 2000) of a particular campaign because this is what clients will use to measure the success of communication strategies and campaigns that are targeted to a particular case. When evaluating or measuring a particular strategy, there is need to put into consideration the outputs in terms of time to be taken and the budget needed. In addition, there is need for prioritization of the needs and what they are benchmarked against. Moreover, tools of evaluation may vary depending on the type of campaign and the targeted audience. There are various methods of media relations evaluations that are currently used in the Public Relations Industry. Some of these methods can be applied to the (EFA) campaign. One method of evaluation is the use of Advertising Value Equivalence (AVE). Michaelson and Griffin (2005), posits that it is â€Å"the approximate calculation of the cost of value of a purchase of advertising that has a size and location in a given publication on a specific day† However, they content that this method has characteristic pitfalls and has therefore fallen out of favour by public relation practitioners. Another method of evaluation is the simple content analysis which is â€Å"An elemental analysis that categorizes or codes what is written in categories that can be statistically analyzed. The codes are developed by a close contextual review of a sample of articles. The remaining articles are reviewed based on the presence of these codes. This method only distinctively represents only what is written. expectedmessages or specific items of information that are not included in the codes or do not appear in the articles are not included in the analysis† (Michaelson and Griffin 2005). Prominence analysis is also another method of evaluation and was also applied to the EFA research in evaluating internet use. This analysis takes into account such factors as the publication an article appears, the date, overall size, presence of photography and other art work and size of headlines. Therefore, in a â€Å"sample prominence analysis, each element is given a weight that is factored into an overall score for each article† (Stanton 2007). The EFA research basically tried to evaluate the consequences and impacts of the internet through the analysis of clicking rates of links and blog. Evaluation can also be carried out through message analysis, which differs from simple and content analysis by placing the analysis on the presence of intended messages in articles. â€Å"Key messages are developed based on communication objectives† (Michaelson and Griffin 2005). The communicative objectives are â€Å"translated† into codes that become the basis of analysis. Michaelson and Griffin suggest that the best method in evaluation is to determine the availability of key parameters in the organization that are to be measured and evaluated these parameters are â€Å"right information, incorrect information, misleading and contradicting information and information that has been left out. † This information was used to give an example of how one company; MetLife used this analysis to manage its media relations efforts on two key lines of business. As part of a national education plan to promote annuities, MetLife identified the media as a paramount passage of its messages to consumers. MetLife decided to determine the degree to which correct, incorrect and only partially correct information is included in new stories about annuities. The analysis enabled MetLife to make an association between the degree and length covered by the media when it comes to annuities and the clients’ understanding of the more than thirty years they will likely live in retirement. Through analysis of the kind of information in terms of their correctness or lack of , clients are able to comprehend the type of retirement plans they could choose from those available at MetLife; and made the company to be aware of the directions it needed to take as far as selling annuities was concerned. Evaluation research normally has three phases, that is, formative, process and summative. â€Å"The formative phase involves all activities that define the extent of the campaign† (Payne 2007). It is in this phase where the range of the problem is ascertained, data is collected regarding mediating strategies; and also provides additional illumination regarding the people being targeted by the mediation, budgetary estimates and the constraints to the full attainment of the mission as set by the problem. Focus is on basic research through focus groups and inquiries which provide opinions and attitudes that can inform campaign development. The formative phase serves as the basis for direction and also sets out the budget to be used in the research campaign. It is therefore an initial process that can also be used to analyze and get insights into the audience’s values, fears and their perceptions. In the EFA campaign, formative phase was applied in the identification of the target group that is youths between the ages of thirteen and eighteen. It also involved understanding the current internet use habits among the youths whereby the official system has been seen as being unable to safeguard the safety of these youths (Paul Dylan 2003). The process phase in evaluative research has to do with keeping track of the extent to which the objectives are being achieved. Shapiro (1996) defines monitoring as the â€Å"methodical Compilation and assay of information as projected progresses. † It is based on projections set during the formative phase. The process phase involves collection of data, time taken to carry out the campaign and the trailing classification that is employed. Monitoring occurs mainly to keep track of activities and correct any shortcomings that may arise (Edward 1945). It generally involves keeping a diary of events. Monitoring of progress of the EFA campaign will involve building media relationships through the press or media releases by creating series of professional news or feature articles. The process phase will include launch of social workshops with the aim of accessing the attention of journalists and also establish linkages with groups in the information sector that have showed concern over the EFA issue. Use of directional tactics to provide one-way flow of information and comprehensive reports to interested parties is meant to bear and achieve more support from these audiences. Other ways will be through organization of meeting among community members, visiting local schools to give speeches and use of focused groups to brainstorm on the issue. The end results of the process phase are that people would have internalized the issue at hand and thus raising the success rate of the campaign. The summative phase involves quantification of the success of goals and objectives whereby collected quantitative data is analyzed. It also involves content analysis of the measuring characteristics of the messages. Generally, the summative phase involves propagating and demonstration of the verdict of the campaign process. It involves â€Å"media responses based on readership, calculation of column centimeters in print media or minutes on air† (Salin 2003). The objectives of the EFA campaign were to train parents of Generation Z on safe internet use, as well as the negative influences on their children whenever they accept the unfitting information from websites. They are considered as the target stakeholder group in this campaign, and are the most important source of support in cultivating their children’s habit. Other objectives included the need to increase Generation Z’s awareness in utilizing Internet content and also to counter the oppression of free speech by educating the community about the social, political, and civil liberties concerns involved in the use of computer based communication systems. The outcomes of this campaign are generally to provide more protection to young children from accessing internet sources that are harmful to them. On the issue of training parents on safe internet use, the outcome was that many parents were advised and showed ways through which they could put more productive security and consciousness that is necessary in minimizing access to these sites by the generation â€Å"Z† youths. This campaign was able to shed light on the extent to which generations â€Å"Z† youths are using the internet to access harmful sites that is now a major cause of concern. It was also noted that most parents did not use internet filters to restrain their children. Hence the numerous campaigns that EFA had launched regarding filtering had not been so successful. The â€Å"issue of forcing internet service providers to block content did not only fail to achieve its intended purpose, but also raised fundamental issues regarding human rights violation of the citizens† (Greenfield 1999). Furthermore, the outcome of the campaign showed that only a handful parents utilized the filtering system, while a majority of them assumed that their children would be able to select the websites that were of importance to their development. Moreover the cost of implementing the filtration system was found to be too high hence way above the majority of most parents. Planning and implementation of this programme started with the coming up with the appropriate secondary analysis of the media and preparation of a budget that was to address the issue of brochures and advertisements. The realization timetable occurred over a period of twelve weeks and it involved various actions which included writing letters to the press, designing the advertisements in the media and writing online. All these implementing strategies were done with the focus of providing â€Å"consistent and orderly evaluations of these interventions† (Greenfield 1999). The results of these interventions in creating are varied within the context of trying to get information regarding the topic. A significant number of teenagers were able to release feature stories on the campaign. Circulation and readership of these magazines was also increased. Implementation also focused on the parents the teenagers, because they are the closest people who can check and control internet use by their children. Parents were able to give information that was used in the development of the advertisement of briefs and variations in opinions, and the public that was needed. With changing technological renovations, then it means that people should always be informed on the current changes in technology. The campaign to filter websites cannot be said to be a very effective means to control the generation â€Å"Z† youths. In terms of future campaigns, there should be emphasize on the peer group relationship and the use of the internet by the young people. Campaigns should also focus on other avenues that can be used as a substitution to the internet and public education on harmful consequences of teenagers having unlimited accesses to all sites on the web (Austin 2006). CONCLUSION The importance of evaluation in a communication strategy cannot be over emphasized. Communication strategies need to reflect the overall goals and objectives of the organization so as to bring about a continuum of order and efficiency. The role of campaigns in putting across pertinent issues with regards to communication will be effective through proper utilization of evaluation tools. Public relations agencies have to put up relevant and strong communication strategies that should address the needs of clients. Evaluation process leads to better understanding of the potential outcomes and the costs versus benefits that might accrue as a result of using a particular campaign strategy. REFERENCE Austin, E 2006, Strategic public relations management: Planning and Managing Effective Communication, Bellman Publishing Company, Boston. Edward, B 1945, Public Relations in Business, Bellman, Boston.

Silver-graphene Oxide Composite for Optical Sensor

Silver-graphene Oxide Composite for Optical Sensor KHOSRO ZANGENEH KAMALI ORIGINAL LITERARY WORK DECLARATION FORM ABSTRACT In this work, a [emailprotected] oxide ([emailprotected]) nanocomposite-based optical sensor was developed for the detection of biomolecules such as dopamine (DA), ascorbic acid (AA), and uric acid (UA). An aqueous solution of [emailprotected] was prepared using a simple chemical reduction method, and it showed a characteristic surface plasmon resonance (SPR) band at 402 nm. The SPR features of the [emailprotected] nanocomposite were used for the detection of DA, AA, and UA. The SPR intensity-based limits of detection (LoDs) of DA, AA, and UA were 49 nM, 634 nM, and 927 nM, respectively. The SPR band position-based LoDs of DA, AA, and UA were 30 nM, 1.64 à ¯Ã‚ Ã‚ ­M, and 2.15 à ¯Ã‚ Ã‚ ­M, respectively. The present optical sensor was more sensitive to DA than to UA and AA. The interactions of the biomolecules with [emailprotected] were studied based on the density functional theory (DFT), and it was found that DA had more interaction than AA and UA. This novel [emailprotected] nan ocomposite is simple to prepare and showed excellent stability and sensitivity toward the detection of biomolecules. The similar material is used for colorimetric detection of Mercury(II) ions (Hg(II)) that is able to show existence of 100  µM Hg(II) ions in solution by naked eyes. The development of this optical sensor for Hg(II) using silver nanoparticles (Ag NPs) is based on the decrement in the localized surface plasmon resonance (LSPR) absorption of the Ag NPs and the formation of silver-mercury (AgHg) amalgam. It is observed that increasing Hg(II) ions concentration in the solution results in the decrease of LSPR intensity and decolouration of the solution. The existence of GO prevents the agglomeration of Ag NPs and enhances the stability of the nanocomposite material, enabling this material to be used in industrial and real sample applications. ABSTRAK Di sini, oksida perak @ graphene (Ag @ GO) berdasarkan nanokomposit-sensor optik telah dibangunkan untuk mengesan biomolekul seperti dopamine (DA), asid askorbik (AA), dan asid urik (UA). Larutan akueus Ag @ GO telah disediakan dengan menggunakan kaedah pengurangan kimia yang mudah, dan ia menunjukkan satu ciri plasmon permukaan resonans (SPR) band di 402 nm. Ciri-ciri SPR daripada Ag @ GO nanokomposit telah digunakan untuk mengesan DA, AA, dan UA. Had keamatan-pengesanan (LoDs) bagi SPR berdasarkan daripada DA, AA, dan UA adalah masing-masing 49 nM, 634 nM, dan 927 nM,. The band SPR berdasarkan kedudukan-LoDS daripada DA, AA, dan UA adalah masing- masing 30 nM, 1.64 uM, dan 2.15 uM. Sensor optik masa kini adalah lebih sensitif kepada DA daripada UA dan AA. Interaksi daripada biomolekul dengan Ag @ GO dikaji berdasarkan ketumpatan teori fungsional (DFT), dan didapati bahawa DA mempunyai interaksi lebih daripada AA dan UA. Novel ini Ag @ GO nanokomposit adalah mudah untuk menyediakan dan menunjukkan kestabilan yang sangat baik dan kepekaan terhadap pengesanan biomolekul.Bahan yang sama telah digunakan untuk pengesanan colorimetric ion Mercury(II), (Hg(II)) yang mampu dilihat dengan kewujudan 100 ÃŽÂ ¼M ion Hg(II) dalam larutan dengan mata kasar. Pembangunan sensor optik bagi Hg(II) menggunakan nanozarah perak (Ag NPS) adalah berdasarkan pengurangan pada penyerapan Ag NPs resonan plasmon permukaan setempat (LSPR) dan pembentukan amalgam perak-merkuri (AgHg). Dapat diperhatikan bahawa peningkatan kepekatan ion Hg(II) memberikan hasil pengurangan pada intensiti LSPR dan perubahan warna. Peningkatan jumlah ion Hg(II) pada satu tahap membawa perubahan dalam morfologi Ag NPs dan pembentukan amalgam AgHg yang mempengaruhi LSPR Ag NPS dan menjadikan perubahan warna pada [emailprotected] Kehadiran GO menghalang penggumpalan Ag NPS dan meningkatkan kestabilan bahan nanokomposit yang membolehkan bahan ini untuk digunakan dalam industri dan aplikasi sampel sebenar. ACKNOWLEDGEMENTS / DEDICATION TABLE OF CONTENTS Table of Contents SILVER-GRAPHENE OXIDE COMPOSITE FOR OPTICAL SENSOR APPLICATIONS ORIGINAL LITERARY WORK DECLARATION FORM ABSTRACT ABSTRAK ACKNOWLEDGEMENTS / DEDICATION TABLE OF CONTENTS LIST OF FIGURES LIST OF TABLES LIST OF SYMBOLS AND ABBREVIATIONS LIST OF APPENDICES CHAPTER 1: INTRODUCTION CHAPTER 2: LITRETURE REVIEW 2.1. Plasmonic band of metal Nanoparticles 2.2. Graphene Oxide 2.3. Sensor 2.3.1. Electrochemical sensor 2.3.2. Surface enhanced Raman scattering 2.3.3. Optical sensor 2.4.2 Amalgamation and LSPR CHAPTER 3: MATERIALS AND METHODS 3.1. Chemicals and Reagents 3.2. Preparation of [emailprotected] Nanocomposite 3.3. Characterization Techniques 3.4. Optical Detection of Biomolecules 3.5. Optical Detection of Hg(II) ions CHAPTER 4: RESULTS AND DESCUSSIONS 4.2. Optical Sensing of Biomolecules using [emailprotected] Nanocomposite 4.2.1. Morphological Studies of [emailprotected] after Addition of Biomolecules 4.2.2. Raman Studies of [emailprotected] Nanocomposite 4.2.3. Computational Studies 4.3. Optical sensing of Hg(II) ions 4.3.1. Optical properties of [emailprotected] nanocomposites 4.3.2. Optical sensing of Hg(II) ions by [emailprotected] nanocomposite 4.3.3. Mechanism for the Amalgamation based detection of Hg(II) ions with [emailprotected] nanocomposite 4.3.4. Characterization of [emailprotected] nanocomposite before and after addition of Hg(II) ions 4.3.5. Selectivity of [emailprotected] nanocomposite based optical sensor 4.3.6. Practical application CHAPTER 5: CONCLUSION AND DISCISSION REFERENCES Supplementary Appendix LIST OF FIGURES Figure 1: UV-vis absorption spectra of (a) AgNO3 (b) GO, and (c) [emailprotected] nanocomposite. Inset: Photograph obtained for the aqueous solution of synthesized [emailprotected] nanocomposite. Figure 2: (A) Absorption spectra obtained for [emailprotected] nanocomposite upon each addition of 100 nM DA. (B) Plot of absorption intensity vs. DA concentration. (C) Plot of Id vs. DA concentration. (D) Plot of ÃŽ »max vs. DA concentration. Figure 3: (A) Absorption spectra obtained for [emailprotected] nanocomposite upon each addition of 5  µM AA. (B) Plot of absorption intensity vs. AA concentration. (C) Plot of Id vs. AA concentration. (D) Plot of ÃŽ »max vs. AA concentration. Figure 4: (A) Absorption spectra obtained for [emailprotected] nanocomposite upon each addition of 5  µM UA. (B) Plot of absorption intensity vs. UA concentration. (C) Plot of Id vs. UA concentration. (D) Plot of ÃŽ »max vs. UA concentration. Figure 5: TEM images of (A) as-prepared [emailprotected] nanocomposite and after additions of (B) AA, (C) UA, and (D) DA. Figure 6: Raman spectra of (a) [emailprotected] and (b) [emailprotected] with 1-à ¯Ã‚ Ã‚ ­M additions of (b) DA, (c) UA, and (d) AA. Figure 7: Electron density map and energy gap of HOMO and LUMO energy levels for Ag and DA, UA, and AA adducts, respectively calculated by DFT methods. Figure 8: Absorption spectra for the (a) AgNO3, (b) GO and [emailprotected] nanocomposite. Figure 9: Absorption spectral changes observed for the [emailprotected] nanocomposite (A) before and (B) after the addition of 200  µM Hg(II) ions. Inset: The digital photographic images taken for the corresponding solution. Figure 10: (A) Absorption spectral changes observed for [emailprotected] nanocomposite upon each addition of 100 nm ÃŽ ¼M of Hg(II) ions to the solution. (B) Plot of changes in the absorption intensity maximum at ÃŽ »LSPR of [emailprotected] nanocomposite against various Hg(II) ions concentr Figure 11: (A) Schematic explain the function of GO in the detection Hg(II) ions. (a) Addition of Hg(II) ions into a solution containing [emailprotected] nanocomposite. (b) Adsorption of Hg(II) ions on the surface of GO. (c) Interaction of Hg(II) ions with Ag NPs and formation of AgHg amalgam. (B) Schematic representation for the formation of AgHg amalgam and its influence in absorption spectra of the Ag NPs present in the [emailprotected] nanoparticles. Figure 12: Overview and high magnification TEM images obtained for the [emailprotected] nanocomposite before (A andB) and after addition of 200  µM Hg(II) ions (C and D). Figure 13: X-ray diffraction patterns obtained for the [emailprotected] nanocomposite (a) before and (b) after addition of 200  µM Hg(II) ions. Figure 14: XPS spectra obtained for the AgHg amalgam particles and their corresponding (A) Ag 3d and (B) Hg 4f regions of core-level spectra. Figure 15: Cyclic voltammograms recorded in 0.1 M phosphate buffer solution with pH 7.0 at a scan rate of 50 mV s−1 for the GC electrode coated with the solution containing [emailprotected] nanocomposite (A) before and (B) after addition of 200  µM Hg(II) ions. Figure 16: Difference in percentage of Ag NPs absorbance peak reduction observed for [emailprotected] nanocomposite in the presence of 200  µM Hg(II), Na(I), K(I), Mn(II), Ni(II), Zn(II), Co(II), Cu(II), Fe(II) and Fe(III) into the individual solutions. Inset: Photograph taken after the addition of 200  µM of Hg(II) ), Na(I), K(I), Mn(II), Ni(II), Zn(II), Co(II), Cu(II), Fe(II) and Fe(III) into the individual solution. LIST OF TABLES Table 1: Analytical performances of [emailprotected] nanocomposite for the detection of DA, UA and AA in human urine sample. Table 2: Comparison of the sensing performance of some of the Ag NPs towards Hg(II) ions. Table 3: Determination of Hg(II) ions in different water samples by using [emailprotected] nanocomposite. LIST OF SYMBOLS AND ABBREVIATIONS DAdopamine UAuric acid AAascorbic acid LoD limit of Detection LSPRlocalized surface plasmon resonance SPRsurface plasmon resonance SERSsurface enhanced resonance plasmon scattering mmili  µmicro nnano Mmolar HPLChigh-performance liquid chromatography NPsnanoparticles Hg(II) ionmercury (II) ion GOgraphene oxide rGOreduced graphene oxide GCEglassy carbon electrode eVelectron volt DFTdensity functional theory HRTEMhigh resolution transmission electron microscope XRDX-ray diffraction XPSX-ray photoelectron spectroscopy FESEMfield emission scanning electron microscope a.u.arbitrary unit LIST OF APPENDICES CHAPTER 1: INTRODUCTION For several decades, silver (Ag) nanoparticles have been attracting attention because of their excellent optical and electronic properties, high catalytic activity, and biocompatibility. Hence, they are used in a wide range of applications such as catalysis 1, solar cells 2,3, and optical 4 and electrochemical sensors 5. Ag nanoparticles possess a sharp absorption in the visible region (400–500 nm), depending on the size of the nanoparticles. This absorption feature arises from the surface plasmon resonance (SPR), which is the absorption of light by the nanoparticles because of surface vibrations between atoms 6–8. This SPR feature allows Ag nanoparticles to be used in optical sensors for the detection of toxic metals 9, biomolecules 10, and organic compounds 11. The addition of any analyte to the Ag nanoparticles leads to assembled/aggregated nanoparticles. This influences the SPR absorption band and is extensively used to follow the molecular recognition processes. Dopamine (DA) is an important catecholamine that belongs to the family of excitatory chemical neurotransmitters. It plays an essential role in the functioning of the drug addiction, cardiovascular, renal, central nervous, and hormonal systems, and in Parkinson’s disease 12. Thus, it is very important to develop a simple sensor for the detection of a sub-micro-molar concentration of DA. In recent years, the detection of biomolecules such as uric acid (UA) and ascorbic acid (AA) in human fluids such as urine and serum has gained considerable attention 13. A deficiency or excess amount of UA in the body causes several diseases, including Lesch/Nyhan syndrome, hyperuricaemia, and gout 14. Cardiovascular disease and kidney damage result from an elevated UA concentration in serum 15. Analytical methods such as high-performance liquid chromatography (HPLC) 16, spectrofluorimetry 17, spectrophotometry 18, mass spectrometry 19, and electrochemical sensors 20 have been reported for the detection of these neurotransmitter molecules. However, the existing detection methods have several limitations such as the need for expensive equipment, well-trained operators, and tedious sampling and time-consuming procedures. Alternatively, an optical sensor platform is more attractive for sensing a wide range of analytes. It is cost effective, portable, has a rapid response, and can provide real-time analyses. Recently, Ramaraj and his coworker reported a silicate-Ag nanoparticle-based optical sensor for the detection of DA, UA, and AA with LODs of 5, 5, and 1 nM, respectively 9 (Figure 1). Most commonly, Ag nanoparticles are synthesized using various chemical and physical methods, which are not eco-friendly and suffer from problems that include the poor reproducibility and stability of the Ag nanoparticles due to colloidal aggregation 21. In order to overcome such limitations, considerable efforts have been made to prepare Ag nanoparticles on polymer 22, silicate sol-gel 11, and graphene nanosheets 23. Among these, Ag-graphene has a large surface area and strong van der Waals force between the graphene and Ag nanoparticles, which significantly reduces nanoparticle aggregation. In addition, the high interfacial interactions ensure the stability of the Ag nanoparticles 24. In this study, graphene oxide-supported Ag nanoparticles were prepared using a simple chemical reduction method and used in an optical sensor for the detection of biomolecules such as DA, AA, and UA (Figure 2). The present synthetic method for the for preparation of [emailprotected] nanocomposite has a dvantages over other methods 11, 21-24 such as, long term stability, high homogeneity, rapid and ease of preparation and avoids any surfactant, stabilizers. Silver nanoparticles (Ag NPs) attracted much attention due to its biocompatibility, high catalytic activity, anti-bacterial activity, electronic and optical properties 25–28. The Ag NPs possess a principal absorption band in the region of 400 nm due to the localized surface plasmon resonance (LSPR)29,30. This SPR feature of Ag NPs is aroused due to the collective oscillation of electrons on the surface of the Ag NPs that are excited by incident electromagnetic waves 31. The SPR band position and intensity mainly depend on the size, shape and refractive index 32. This SPR band of Ag NPs is more sensitive to the surrounding environment and it significantly influences the band position and intensity. Based on the changes in the LSPR band position and intensity, an optical sensor platform with Ag NPs was developed to detect the wide range of analytes, including biomolecules 33, nitroaromatics 34, phenolic compounds 35, and heavy metal ions 36. Among the investigated analytes, heavy metal ions especially Hg(II) ions are more often monitored with Ag NPs through the optical sensing method owing to its high toxicity and solubility in water37. Mercuric (Hg(II)) ions are mainly released into the atmosphere from solid waste incineration, power plants, and bumping fossil fuels38 that pollute water, soil and air 39,40. The existence of Hg(II) ions in water causes serious damage to the brain, nervous system, kidneys and endocrine system of living organisms41. Developing a system for detecting Hg(II) with high sensitivity and selectivity against other common metal ions dissolved in water is a challenge in recent years 42–47. From an environmental point of view the development of an inexpensive, simple, selective and sensitive method of detection of Hg(II) becomes highly important. There are many types of sensors invented to detect Hg(II) in the environment. Some studies reported the detection of Hg(II) ions using electrochemical methods 48,49. Although they achieved a very high limit of detection (LoD), they need to use expensive apparatus and complicated setup. For the electrochemical testing of Hg(II) sample, the fabrication of an electrode is necessary, and that is a very tedious process. In addition, the detection of Hg(II) using fluorescence spectrometry has been widely investigated 50,51. Although this method is simple and is able to detect trace amounts of Hg(II) ions in solution, it requires expensive equipment to work. In this respect, colorimetric sensors are cheaper and do not require tedious preparation methods, colorimetric sensors have the advantage that the existence of Hg(II) is easily discernible to the naked eye without being affected by other possible dissolved ions 52–59. Recently, Hg(II) ion sensing was reported with noble metals su ch as Au and Ag by utilizing the size/interparticle distance-dependent optical properties and high extinction coefficients 60–62. The interaction between surfactants and metal NPs results in changes to the refractive index of these NPs and the LSPR band 32,33. They also may electrostatically repel the analyte, preventing it from interacting with the metal NPs and reduces the sensitivity of the sensor. In this study, the Ag NPs was prepared by using a simple chemical reduction agent and stabilized on graphene oxide (GO) sheets. Subsequently, the [emailprotected] nanocomposite was used to develop a colorimetric sensor for the detection of Hg(II) with the naked eye and an optical sensor also developed based on the LSPR changes upon the addition of various Hg(II) concentrations. This significant change in the LSPR of the Ag NPs is due to change in the morphology through the formation of AgHg amalgam. Selectivity in the detection of Hg(II) in the presence of various environmentall y relevant metal ions was also studied. CHAPTER 2: LITRETURE REVIEW 2.1. Plasmonic band of metal Nanoparticles Most probably gold nanoparticles (NPs) synthesized in the 5th or 4th century BC in China and Egypt regions 63. From that time, gold NPs have been used in both medicine and aesthetic aspects. As the result of the interesting optical properties of gold NPs, they were used for changing color of glass 64, pottery and ceramics 65. Faraday got interested about the optical properties of gold NPs and reported about the range of colors of gold nanoparticles colloidal solutions from ruby red to amethyst in 1857. Then he studied the factors influencing the color of gold NPs solutions and concluded that ‘‘the mere variation in the size of particles gave rise to a variety of resultant colors’’. Other than their optical properties, many applications of metal nanoparticles have been found in biochemistry, catalysis and sensors. For instance, one of the anti-odour commercialized devices in Japan is using the technology of immobilizing gold nanoparticles in oxide matrixes as active oxidation catalysts 66. In defenitions, nanoparticles are particles composed of number of atoms, ranging from 3 to 107 67. Nanoparticles feature properties are different from atoms or bulk material due to their size. The metallic nanoparticles larger than 2 nm possess a strong and broad absorption band in the UV-visible spectrum that is called surface plasmon resonance (SPR) band. This absorbance has discovered by Gustav Mie and known as Mie resonance 67. For smaller nanoparticles, quantum effects become more prominent and LSPR disappears. All metal nanoparticles possess the mensioned optical property, but the series of Au, Ag and Cu have very intense LSPRs. Other than that, their easy synthesis methods and their robustness to environmental conditions made silver and gold NPs to widely be used in this field. The LSPR features such as position, shape and intensity are strongly depends on various factors, to mention: the changes in the interparticle distance of the NPs and , a nd the changes in the refractive index of the local surrounding environment 68. There are indeed other types of plasmonic signals, such as the surface plasmon resonance band produced by planar metallic films, in reflection or transmission, some of them being called plasmon polaritons. Though the resulting physics is extremely exciting and the recent discoveries numerous, it is out of the scope of present thesis and they will not discuss further. In recent years, many theories were adopted by both physicists and chemists in order to give a clear description of the SPR band and on the main factors impacting its position, broadness and intensity. Many works has done to overview the existing plasmon band theories 67, and explain the SPR band by Mie and effective medium theory 69. There are some researches to explain optical propertiese of NPs with arbitrary shape by Maxwell equation theory 6. The phenomenon on absorbance of certain wavelength of light observed in transmission of light through metal nanoparticles in solid or solution phase, is called localized surface plasmon resonance band (LSPR).Nanoparticles intract with incident light in certain frequency that result global scattering of it. This observation can be explained by the collective resonance of the conduction electrons of the nanoparticle, due to interaction of electrons in nanoparticles with light. The evaluation of all parameters of material, specially its dielectric constant is necessary for understanding and study this phenomena. Usually, dielectric constant of nanoparticles count same as its bulk form and confinement effects and defects induced by edges or impurities will be neglected. For this aim a study on electrostatics in bulk metal by using Maxwell equations is necessary. In formulating the dielectric constant with known parameters, the Drude model, which describes the motion of free electrons in a metal can be applied. Then the question of the nanoparticles will be addressed: the conditions for conducting electrons resonance will be determined by several means. The determination of the frequency of the absorption maximum (denoted , the frequency of the Mie resonance), the height of this maximum and the width of the peak will be the ultimate goal of the calculations. The different geometrical confinement effect of free electrons on each material caused the electronic motion for nanoparticles vary material by material. Indeed, here the nanoparticles can be seen as a cationic network in which a cloud of conducting electrons (or free electrons) moves and oscillates. Nanoparticles dimensions are very small compared to the wavelength of the UV-visible light for which the phenomenon is observed and also comparable to the mean free path of electrons. The surface plasmon band is known to the resonance of the electronic cloud with the incident wave and the mechanics of this phenomeno n can be evaluated. In the case of nanoparticles, the conditions that electron cloud can resonate needs to be calculated. For this aim, The dielectric constant of metal nanoparticles assumed to be the same as the bulk material. Some postulates then become incorrect, but in calculation we have to keep them as an approximation. For instance, the electron density in small particles (r = 0) is not uniform and the charge will accumulate in particle edges and surface. Other than that, since the size of nanoparticles is very small comparing to the wavelength of incident light, we can consider that all electrons in the nanoparticle face with the same field at the given time and the electric field is independent of position 67. This hypothesis is known as the quasi-static approximation. When the electric field incidents to the particle, it result the displacement of the electron cloud that leads to the creation of surface charges. The positive charge would be where the cloud is lacking and the negative charge would be where it is concentrated (Fig. 1). 67 The therm â€Å"surface† is justified by the electron cloud charge mentioned in previous statements. However, we have to kep in mind that all the electrons are moving together (collectively) under the influence of electromagnetic field. This collective oscillation leads to plasmon polaritons, 64 that is different with the free plasmon in the bulk metal.67 The term â€Å"plasmon† was given to the SPR phenomenon by Shopper, due to the bounded gaseous plasmon oscillations.67 The dipolar charge repartition imposes a new force on the electron cloud. The electrons undergo a restoring force which conflicts with the external electric field. Figure.‎0.1. Schematic description of electronic cloud displacements in nanoparticles under the effect of a electromagnetic wave. 2.2. Graphene Oxide Recently, chemically modified graphene (CMG) has been studied in the context of many applications, energy-related materials, such as polymer composites, ‘paper’-like materials, field-effect transistors (FET), sensors, and biomedical applications, due to its excellent electrical, mechanical, and thermal properties. 70–72 Chemical modification of graphene oxide, which is generated from graphite oxide, has been a promising route to achieve mass production of CMG platelets. Graphene oxide contains a range of reactive oxygen functional groups, which renders it a good candidate for use in the aforementioned applications (among others) through chemical functionalizations. Although graphene known a relative novel material of broad interest and potential,1,3 GO has a history that extends back many decades to some of the earliest studies involving the chemistry of graphite.4–6 The first, the British chemist B. C. Brodie was exploring the structure of graphite by investigating the reactivity of f