Identification of an unknown stain encountered at a crime scene, especially where the context of the case does not provide an indication to the identity of the stain, currently requires a number of time consuming and costly presumptive and confirmatory tests to be performed. Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopic method that could allow crime scene analysts to identify unknown stains rapidly both in the laboratory and in the field. The SERS technique utilizes a laser, which interacts with molecules applied to a gold nanoparticle chip (SERS substrate) that enhances the normal Raman signal, producing a shift in energy characteristic of the vibrational modes present. Therefore, the light scattering spectrum obtained provides the analyst with a unique spectral fingerprint of the molecular components of the sample. The advantages of this SERS based method include its high sensitivity, speed, non-destructive nature, ease-of-use, minimal sample preparation requirement, portability, and multiplexing capabilities. In contrast to conventional Raman spectroscopy, SERS offers higher sensitivity resulting in small sample volumes (approximately 1 μL or less) being required for sample identification and the ability to process dilute solutions. This allows for the remaining sample to be used for other forensic tests, making the technique an ideal analytical method for use at a crime scene. vi It is hypothesized that SERS can be coupled with multivariate statistical methods, such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) to be established as a confirmatory technique in the forensic analysis of human body fluids. It was concluded that semen produces a spectral pattern that is consistent and readily distinct from blood, saliva, urine and vaginal fluid. In addition, this investigation identified and characterized semen from four donors, utilizing liquid semen as well as semen stains on cotton swatches and glass cover slips. Reproducibility was established by analyzing three separate SERS chips for every sample and/or solution. Ten spectra of each chip were obtained, averaged, and then compared to one another. A protocol was designed for the extraction of dried semen stains on cotton swatches and application to a SERS chip. Different extraction conditions were performed, varying both the volume of water used and the time the cutting remained submerged in the water, resulting in optimal signal from 5 μL of water for 5 minutes. Additional parameters including analysis of the perimeter of the stain and the use of saline as an extractant were examined. A second protocol for the extraction of dried semen stains from a glass cover slip was designed and tested, utilizing 1 μL of water. All experimental spectra were subjected to PCA for comparison with neat semen, and determined to be consistent. Additionally, a mixture of semen and vaginal fluid was evaluated. Visual inspection and PCA of the resulting spectra demonstrated that the mixture was a combination of both body fluids. Such samples are of particular importance in sexual assault cases. vii In summary, this preliminary study of the identification of semen using SERS demonstrates the potential for the method to be used as an investigative tool for the detection of trace amounts of human body fluids at crime scenes and within forensic laboratories. Not only is semen differentiable from other body fluids, but it is also capable of being extracted from stains and successfully identified by SERS

Intracellular redox potential is a delicately balanced property in cells. It plays an important role in the regulation of cellular processes and dysfunction of the redox state is believed to get involved in initiation of many kinds of diseases. However, lack of suitable techniques for quantitatively monitoring the redox potential in cells with a wide range is a significant challenge. My project aims to develop SERS nanosensors for measuring intracellular redox state quantitatively and applying them to quantify hypoxia, which is generally described by the cell having a reducing environment and defined as a form of “reductive stress”. Four redox active probe molecules have been synthesised and characterised. Their Raman spectra all change as a function of local redox potential. Since these probe molecules can be assembled on gold nanoshells which are able to enhance the Raman Effect significantly, we can calculate the redox potential from simple optical SERS measurements. Transmission Electron Microscopy was used to investigate the cellular delivery of nanosensors. TEM images confirmed that either single nanosensor or small aggregates can be taken up controllably by cells and translocated in the cytoplasm. The introduction of nanosensors was also found not to be toxic to the cells. The nanosensor has been used to monitor the redox potential in resting cells as well as the redox changes when cells responded to pharmacologically induced hypoxia and oxidative stress. These measurements demonstrated that the SERS based nanosensor developed is able to monitor the intracellular redox change in a reversible, noninvasive way and respond to cellular hypoxia quantitatively.

Raman spectroscopy is normally a non-destructive, highly selective technique that has become an ubiquitous tool for analytical chemists. One of the primary limitations of Raman spectroscopy, however, is the relatively low cross-section of the technique. With signal enhancements relative to normal Raman scattering as high as 1011, the ultra-trace detection of adsorbates down to the single molecule level has been achieved with SERS. Despite the dramatic improvement in the sensitivity and the high selectivity afforded by the SERS method, the acceptance of SERS as a general analytical tool has been hindered by a lack of stability and reproducibility in the substrates. This lack of stability has been particularly troublesome because unstable substrates exhibit reduced shelf lives as well as a reduced ability to monitor processes that occur under non-ideal conditions such as high temperature or harsh chemical environments. In this thesis, two different works are reported that address the two major hurdles facing the SERS field in the development of a stable and reproducible SERS substrate. First, the development of a SERS-active substrate that exhibits improved temporal and thermal stability and is capable of in-situ high temperature measurement of analytes adsorbed on the surface is presented. The substrates are prepared by depositing an ultra-thin layer of alumina by Atomic Layer Deposition (ALD) onto silver island films grown by thermal evaporation. We demonstrate the application of alumina-coated substrates to the measurement of the dehydration of trace amounts of calcium nitrate tetrahydrate as a function of temperature. As a development of the above mentioned work, the combination of a silver/gold layered architecture obtained by thermal evaporation with an ultra-thin alumina overlayer to generate a re-usable SERS substrate that is simple, relatively inexpensive and stable is reported. The relative thicknesses of the silver and gold and the alumina overlayer was optimized to deliver the maximum SERS enhancement and optimal stability when the substrate was subjected to high temperature. Utilizing the method of thermal desorption of the analyte, the substrate surface is regenerated and able to be reused multiple times with little reduction in SERS activity. Second, in the development of a reproducible SERS substrate, the application of monodisperse silver nanocube colloidal substrate in microfluidic SERS is demonstrated. In static SERS experiments, one often has to search for “hot spots”, which are positions of a drastically increased SERS signal compared to the rest of the probe volume, in an inhomogeneous solution. To overcome this problem and prevent the decomposition and or fragmentation of SERS substrate and analyte, respectively, the implementation of flow cell is a promising way. At the beginning analyte, colloidal solution and aggregation agent were brought into a mixing chamber, where they were thoroughly mixed before being directed to a sample cell for detection. With this method, a relatively high amount of sample volume is necessary. In addition to the advantages listed above, efforts have been made to reduce the required amount of the sample solution by the design of low-cost poly (dimethylsiloxane) chips via soft lithography technique. The sample solution is passively pumped through the microfluidic channel, where an optical detection window is implemented for acquisition of a SERS spectrum.

In this thesis, we focus on theoretical investigations on metal interfaces where many heterogeneous chemical reactions take place. Surface-enhanced Raman scattering (SERS) spectroscopy and the modern electrochemical methods are important in-situ techniques that have been widely employed for a variety of applications. Theoretical simulations have become an indispensable tool to infer the molecular details of interfacial structures that are not directly accessible from experimental measurements. In this context, we have proposed several new theoretical models for both SERS and interfacial electrochemistry, which allow us to provide molecular-level understanding of the interfacial structures under the realistic experimental conditions.   The first part of the thesis has addressed the basic theory of SERS that offers the vibrational structure of the interfacial molecules. It is well known that the huge enhancement of Raman intensity in this technique can be attributed to two independent factors, namely the physical and chemical enhancements. The former is resulted from the enhanced electromagnetic field induced by the plasmonic excitations, while the latter comes from the changing of interaction between the molecule and the surface. The interplay between these two enhancement factors, which has long been an issue of debate, is revealed in this thesis. They are coupled through molecular polarizability. A practical computational approach is proposed and used to demonstrate the importance of the coupling on different molecular systems. It is found that for certain systems the coupling factor can be as large as 106. This finding is of great importance towards a comprehensive understanding of the SERS mechanisms and a quantitative prediction of the enhancement factor.   The other part of the thesis is devoted to the theory of interfacial electrochemistry, in particular the effects of water solution. A novel protocol that combines classical molecular dynamics (MD) and the first principles density functional theory (DFT) calculations is proposed to address the statistical behavior of interfacial properties. Special attention has been paid to the work function of Pt(111) surface and CO adsorption energy on Pt(111) surface in aqueous solution. It has been found that in this case the work function of Pt surface illustrates a surprisingly broad distribution under the room temperature, sheds new light on the understanding of reaction activity of the surface. The proposed protocol is able to provide results in very good agreement with experiments and should be applied routinely in future studies. / <p>QC 20120515</p>

Large and small nanospheres, large and small nanoplates, nanorods and nanostars have been synthesized and fabricated into SERS substrates consisting of sandwiched and aggregated structure. Using 633 nm laser as excitation, individual SERS spectra of each labeling molecules, benzenethiol, 4-nitrobenzenethiol and 4-quinolinethiol, have been successfully obtained and the combination of these three molecules have the least amount of overlapping and can all be identified from the reference multiplexed spectra. Among all the substrates that have analyzed, the substrate made from nanospheres with sandwiched structure is able to produce multiplexed SERS spectra with more details and higher reproducibility. Although multiplexed SERS spectra can also be observed from substrates made from small nanoplates, nanostars and nanorods substrates with sandwiched structures, the unique peaks representing the labeling molecules are less consistent in their intensity. In addition, substrates with micro sized plates in sandwiched configuration are found to exhibit much lower SERS activities and this can be due to the size of the plate being much greater than the light source, restraining the surface plasmon resonance effect. Most of the substrates fabricated with aggregated nanoparticles have very low reproducibilities and saturated signals with 633 nm excitation. The spectra peaks are much easier to identify and are much more reproducible when 785 nm excitation have been adopted. This can be due to the size of the aggregated nanoparticles are much bulkier which a deeper penetrating light source is required to induce more molecules labels to exhibit SERS activities. A novel SERS substrate has been fabricated with nanoparticle-thiol-microplate sandwiched configuration by using a double ended thiol molecules, benzenedithiol, to strongly connect nanospheres and the plates together. However, the measurement of the SERS activity is limited by the overpowering of the light source, which has frequently melted and evaporated the plate samples once they have been exposed to the excitation radiation. In addition, instead of spreading evenly on the microplate surfaces, the nanoparticles have appeared to be aggregated which may have increased the difficulty in obtaining SERS activity.

Large and small nanospheres, large and small nanoplates, nanorods and nanostars have been synthesized and fabricated into SERS substrates consisting of sandwiched and aggregated structure. Using 633 nm laser as excitation, individual SERS spectra of each labeling molecules, benzenethiol, 4-nitrobenzenethiol and 4-quinolinethiol, have been successfully obtained and the combination of these three molecules have the least amount of overlapping and can all be identified from the reference multiplexed spectra. Among all the substrates that have analyzed, the substrate made from nanospheres with sandwiched structure is able to produce multiplexed SERS spectra with more details and higher reproducibility. Although multiplexed SERS spectra can also be observed from substrates made from small nanoplates, nanostars and nanorods substrates with sandwiched structures, the unique peaks representing the labeling molecules are less consistent in their intensity. In addition, substrates with micro sized plates in sandwiched configuration are found to exhibit much lower SERS activities and this can be due to the size of the plate being much greater than the light source, restraining the surface plasmon resonance effect. Most of the substrates fabricated with aggregated nanoparticles have very low reproducibilities and saturated signals with 633 nm excitation. The spectra peaks are much easier to identify and are much more reproducible when 785 nm excitation have been adopted. This can be due to the size of the aggregated nanoparticles are much bulkier which a deeper penetrating light source is required to induce more molecules labels to exhibit SERS activities. A novel SERS substrate has been fabricated with nanoparticle-thiol-microplate sandwiched configuration by using a double ended thiol molecules, benzenedithiol, to strongly connect nanospheres and the plates together. However, the measurement of the SERS activity is limited by the overpowering of the light source, which has frequently melted and evaporated the plate samples once they have been exposed to the excitation radiation. In addition, instead of spreading evenly on the microplate surfaces, the nanoparticles have appeared to be aggregated which may have increased the difficulty in obtaining SERS activity.

Research work on fabricating organized and reproducible SERS substrates has been done in this thesis. Nano-aperture arrays with circular, bow-tie and cross bow-tie shapes were fabricated by using FIB milling. These arrays were imaged under SEM and their parameters were measured. The optical transmission properties of these arrays were measured by white light transmission. It was found that the shape of the nano-aperture could determine these arrays’ abilities to support SPR. Different shapes would give different SPR modes and generated optical transmission peaks at varied wavelengths. For nano-aperture array with identical shapes, the varied parameters, such as periodicity or tip-to-tip distances, would affect the position of the transmission peaks. Slight increase or decrease of these parameters can be manipulated to adjust the peak positions, catering to the best resonance of the excitation laser used in Raman spectroscopy. The enhancement properties of these arrays as SERS substrates were measured by Raman spectroscopy. Different SERS enhancement properties could be found across different shaped nano-aperture arrays and cross bow-tie nano-aperture arrays give the best SERS enhancement. For nano-aperture array with identical shapes, the varied parameters would affect its ability of SERS enhancement. Near field simulations were carried out in order to explain the relationship of the SERS results and these arrays’ SPR ability. Electrochemical study on these ordered nano-aperture arrays was also carried out in this thesis. / Graduate

Designer drugs are some of the most commonly abused substances in the world. They are synthesized through slight chemical modifications of existing substances, evading the law while maintaining the desired effects of the pharmaceutical or illicit substance. These drugs are often marketed as “herbal” or “natural,” but are fully synthetic. Due to their constant, rapid emergence, there is a need for a rapid method of identification, both in the field as well as in the laboratory. One group of these designer drugs are synthetic piperazines. Named for the piperazine ring found in their chemical structures, synthetic piperazines are central nervous system stimulants that have the reputation of mimicking the psychoactive effects of the illicit compounds amphetamine and 3, 4-methylenedioxymethampetamine (MDMA). Over the past 10 years, synthetic piperazine cases submitted to forensic laboratories in the United States have greatly increased, including a 30-fold increase between 2007 and 2009 alone. Surface enhanced Raman spectroscopy (SERS) was investigated as a method for the rapid qualitative analysis of synthetic piperazines. SERS is a type of vibrational spectroscopy, which utilizes the interaction of light and matter to elucidate details of the chemical structure of a molecule. SERS combines laser spectroscopy with the optical properties of metallic nanostructures, resulting in strongly enhanced signals from the Raman scattering of light. Each chemical structure will give a unique SERS spectrum and this, coupled with the minimal-to-no sample preparation and the portability of a SERS instrument, makes SERS a strong candidate for the identification of not only synthetic piperazines, but all designer drugs. To evaluate the use of SERS for the qualitative analysis of synthetic piperazines, eight synthetic piperazines were adsorbed onto a SERS substrate. The interaction with the gold nanoparticles enhanced the Raman scattering for all eight of the synthetic piperazines and SERS spectra were obtained. All eight drugs were found to give a robust and reproducible signal, requiring a fewer number of scans, less laser power, and less time for analysis compared with traditional Raman spectroscopy. When compared with traditional Raman spectra, the synthetic piperazines demonstrated sensitivity enhancement factors of up to 10^8 using SERS. A partial least squares-discriminant analysis (PLS-DA) statistical model was built and used to evaluate the analytical sensitivity and specificity of the SERS method. The PLS-DA model helped determine a limit of detection of 10 μg/mL of BZP. All eight synthetic piperazines could be identified by the statistical model below an error rate of 20% when compared to each other- a strong indication of a method with high specificity.Through this research, it has been demonstrated that SERS can be applied efficiently as a qualitative technique for the analysis of synthetic piperazines.

Submitted by LEONARDO NEGRI FURINI null (rocar16@gmail.com) on 2016-03-29T02:57:24Z No. of bitstreams: 1 Tese_Leonardo N Furini.pdf: 2619312 bytes, checksum: b2216153a5a2166faa49fa60ceeb02d0 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-03-29T19:50:09Z (GMT) No. of bitstreams: 1 furini_ln_dr_bauru.pdf: 2619312 bytes, checksum: b2216153a5a2166faa49fa60ceeb02d0 (MD5) / Made available in DSpace on 2016-03-29T19:50:09Z (GMT). No. of bitstreams: 1 furini_ln_dr_bauru.pdf: 2619312 bytes, checksum: b2216153a5a2166faa49fa60ceeb02d0 (MD5) Previous issue date: 2016-02-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Nesta tese filmes de Langmuir foram empregados para estudar a interação entre lipídios e um fungicida denominado carbendazim (MBC) e espectroscopia de impedância e espalhamento Raman amplificado em superfície (SERS, do inglês surface-enhanced Raman scattering) empregados na detecção deste fungicida. Os lipídios utilizados para formar os filmes de Langmuir foram brometo de dioctadecildimetilamônio (DODAB), brometo de didodecildimetilamônio (DDAB), 1,2-dipalmitoil-sn-3-glicerofosfatidilcolina (DPPC) e 1,2-dipalmitoil-sn-3-glicero-[fosfo-rac-(1-glicerol)] (DPPG) e o estudo da interação foi realizado com e sem MBC na subfase aquosa.Os resultados mostraram que o MBC interage fortemente com o DODAB e DDAB, moderadamente com o DPPC e fracamente com o DPPG, indicando que a interação é de origem eletrostática. Unidades sensoriais compostas por eletrodos interdigitados recobertos com filmes LbL de DODAB/NiTsPc e perileno/DPPG compuseram uma língua eletrônica capaz de distinguir diferentes concentrações de MBC em solução via espectroscopia de impedância. Analisando individualmente cada unidade sensorial, a composta pelo filme LbL de DODAB/NiTsPc foi a que apresentou melhor desempenho frente ao MBC. Os estudos SERS foram realizados em três etapas. Na primeira, várias morfologias de nanopartículas foram sintetizadas e avaliadas quais apresentam melhor sinal SERS do MBC. Deste estudo ficou determinado que as nanopartículas esféricas de prata apresentaramo melhor sinal SERS do MBC. A interação do MBC com a superfície destas nanopartículas foi realizada a partir de espectros SERS do MBC em vários pHs. Cálculos teóricos foram utilizados para atribuição dos modos vibracionais do MBC e assim ajudar na interpretação dos resultados experimentais. De principal relevância, das espécies de MBC as formas neutra (MBC0 ) e desprotonada (MBC- ) apresentam afinidade pela superfície de prata, originando assim sinal SERS. Por fim, o limite de detecção do MBC foi determinado via SERS utilizando um procedimento que garante a reprodutibilidade das medidas, uma vez que a técnica SERS não é, ainda, uma técnica analítica de rotina. / This work Langmuir films were employed to study the interaction between lipids and a fungicide called carbendazim (MBC), impedance spectroscopy and surface-enhanced Raman scattering (SERS) were used in the detection of this fungicide.The lipids employed to Langmuir films were dioctadecyldimethylammonium bromide (DODAB), didodecyldimethylammonium bromide (DDAB), 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) with and without MBC in the subphase. The results show that the MBC interacts strongly with DODAB and DDAB, moderately with DPPC and weakly to DPPG, indicating that it is electrostatic interaction. Sensor units composed of interdigitated electrodes coated with LbL films DODAB/NiTsPc and perilene/DPPG composed an electronic tongue able to distinguish different MBC concentrations in solution, via impedance spectroscopy. Analyzing each sensory unit, the composed with LbL film DODAB/NiTsPc showed the best performance. The SERS studies were performed in three stages. The first one, several morphologies of nanoparticles were synthesized and evaluated which have better SERS signal of MBC. From this study it was concluded that the spherical nanoparticles of silver have better SERS signal of MBC and the subsequent results were obtained only with this nanoparticle. The interaction between MBC and surface of these nanoparticles was carried out by SERS spectra of MBC at several pHs. Here, theoretical calculations were used for assignment of vibrational modes of the MBC and thus help in the interpretation of experimental results. According to experimental and theoretical results neutrally (MBC0 ) and deprotonated (MBC- ) species have affinity for the silver surface and then show SERS signal. Finally, the MBC limit of detection was determined via SERS using a procedure which ensures the reproducibility of the measurements, since SERS technique is not, yet, a routine analytical technique. / CNPq: 159047/2012-9

Submitted by Sabrina Alessio Camacho null (sabrina.alessio@gmail.com) on 2018-02-28T15:16:28Z No. of bitstreams: 1 Tese_Sabrina Alessio Camacho.pdf: 5079527 bytes, checksum: 10f4f3ced26424a88ddd35b29e074c25 (MD5) / Approved for entry into archive by Maria Marlene Zaniboni null (zaniboni@bauru.unesp.br) on 2018-02-28T18:45:55Z (GMT) No. of bitstreams: 1 camacho_sa_dr_bauru.pdf: 5079527 bytes, checksum: 10f4f3ced26424a88ddd35b29e074c25 (MD5) / Made available in DSpace on 2018-02-28T18:45:56Z (GMT). No. of bitstreams: 1 camacho_sa_dr_bauru.pdf: 5079527 bytes, checksum: 10f4f3ced26424a88ddd35b29e074c25 (MD5) Previous issue date: 2018-01-24 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho abrange a síntese de nanopartículas metálicas com propriedades plasmônicas específicas incorporadas a filmes finos nanoestruturados de moléculas de interesse, como metaloporfirinas e outras. Nanopartículas de ouro (AuNPs 16 nm) foram incorporadas a filmes Langmuir-Blodgett (LB) de metaloporfirina visando o efeito SERS (espalhamento Raman amplificado em superfície). A incorporação das AuNPs se deu por codeposição, a partir das interações entre as AuNPs (presentes na subfase do filme de Langmuir) e as moléculas de metaloporfirina (espalhadas na interface ar/água). Nanopartículas de ouro recobertas com sílica (Au-SHINs), com tamanhos diferentes (40 e 100 nm) e mesma espessura de recobrimento (10 nm), também foram incorporadas em filmes LB e em solução aquosa visando o efeito SEF (fluorescência amplificada em superfície). Três variáveis foram aplicadas para aumentar a fluorescência: tamanho de nanopartícula, agregação e temperatura da amostra. Resultados teóricos e experimentais mostraram que as Au-SHINs 100 nm apresentam uma intensidade de amplificação cerca de 3 vezes maior e um espalhamento 2 ordens de grandeza maior que as Au-SHINs 40 nm, levando a maiores fatores de amplificação (EF). Além disso, a agregação das Au-SHINs com eletrólito e a diminuição da temperatura da amostra também resultou em maiores EF. Visando uma aplicação ambiental, AuNPs 100 nm e Au-SHINs 100 nm recobertas com 4 nm de sílica foram aplicadas na detecção do herbicida ametrina. Soluções etanólicas com concentração de 10-5 mol/L em coloides de AuNPs e Au-SHINs foram detectadas via SERS. Já em cana-de-açúcar, a detecção foi possível somente com AuNPs, porém, com concentrações no intervalo de 10-4 a 10-8 mol/L, sendo 5,3 x 10-8 mol/L o limite máximo de resíduos de ametrina permitido em produtos agrícolas. Visando uma aplicação biológica, Au-SHINs 100 nm recobertas com 10 e 4 nm de sílica foram utilizadas na fabricação de SEF e SERS tags, respectivamente, para detecção dos antígenos IgM e do vírus da Zika em plataformas de imunoensaio. Os limites de detecção alcançados foram de 5,0 e 12,5 ng/mL para os antígenos IgM e Zika, respectivamente. Neste último caso foi possível a distinção com antígenos da Dengue, evitando a reatividade cruzada, um entrave freqüentemente encontrado em ensaios de diagnóstico da Zika. / The present work covers the synthesis of metallic nanoparticles with specific plasmonic properties incorporated into nanostructured thin films of target molecules, as metalloporphyrins and others. Gold nanoparticles (AuNPs 16 nm) were incorporated into Langmuir-Blodgett (LB) films of metalloporphyrin aiming the SERS effect (surface-enhanced Raman spectroscopy). AuNPs were incorporated by co-deposition, taking advantage of the interaction between the AuNPs (in the Langmuir film subphase) and the metalloporphyrin molecules (sprayed at the air/water interface). Gold shell-isolated nanoparticles (Au-SHINs), with different sizes (40 and 100 nm) and same silica shell thickness (10 nm), were also incorporated into LB films and in aqueous solution targeting the SEF effect (surface-enhanced fluorescence). Three variables were applied to increase the fluorescence: size of nanoparticle, aggregation and sample temperature. Theoretical and experimental results showed that the Au-SHINs 100 nm have an enhancement intensity about 3 times higher and a scattering 2 orders of magnitude higher than the Au-SHINs 40 nm, leading to higher enhancement factors (EF). Besides, the aggregation of Au-SHINs with electrolyte and the sample temperature decreased also resulted to higher EF. Aiming an environmental application, AuNPs 100 nm and Au-SHINs 100 nm coated with 4 nm of silica were applied to detect the herbicide ametryn. Ethanolic solution with concentration of 10-5 mol/L in AuNPs and Au-SHINs colloids were detected via SERS. While in sugar cane, the detection was only possible with AuNPs, however, with concentrations at the range from 10-4 to 10-8 mol/L, being 5.3 x 10-8 mol/L the maximum residual limit of ametryn allowed in agricultural products. Aiming a biological application, Au-SHINs 100 nm coated with 10 and 4 nm of silica were used in the development of SEF and SERS tags, respectively, for detecting IgM and Zika virus antigens on immunoassay platforms. The limits of detection were 5.0 and 12.5 ng/mL for IgM and Zika antigens, respectively. In the latter, it was possible the distinction with Dengue antigens, preventing the cross-reactivity, an obstacle frequently found in diagnostic assays of Zika. / 2013/01897-4