Neste trabalho, pretendeu-se explorar a possibilidade da utilização de SERS em aplicações bioanalíticas empregando papel como substrato. Neste sentido, investigou-se o acoplamento de SERS com a técnica de ring oven e/ou com ferramentas quimiométricas visando compensar as suas limitações, tais como a baixa seletividade, o efeito de matriz, o processo ineficiente de amostragem e de fabricação de substratos SERS baseados em papel.
A utilização do modelo PLS-DA com estimativa de incerteza ainda é pouco explorada no desenvolvimento de métodos quimiométricos, sendo que, até o nosso conhecimento, este é o primeiro modelo utilizado em conjunto com o efeito SERS reportado na literatura. Neste caso, foram utilizados substratos SERS baseados em papel fabricados pelo método clássico ou de imersão. O método SERS-PLS-DA desenvolvido mostrou ser eficiente na discriminação de bactérias no nível de gênero e espécies, após um mínimo preparo de amostra, com resultados muito similares aos obtidos utilizando o sequenciamento do gene 16S rRNA. Essa discriminação bacteriana foi possibilitada pelas diferenças na composição química na parece celular, especificamente na variação da proporção dos produtos de degradação de bases purínicas. Assim, acredita-se que o método poderia ser estendido para a discriminação de uma grande variedade de micro-organismos além de bactérias (vírus, por exemplo), e como método auxiliar no descobrimento de novas espécies bacterianas.
A deposição direta de GNPs em papel de impressão é uma estratégia eficiente e rápida para o preparo de substratos SERS baseados em papel, podendo proporcionar uma repetibilidade adequada para realizar análises químicas quantitativas de amostras com matrizes complexas. A combinação de estudos experimentais e teóricos mostrou que o controle da quantidade de GNPs depositadas é fundamental para a obtenção de substratos SERS com elevado fator de intensificação. Esses substratos SERS foram utilizados para a quantificação in situ de ácido úrico em uma matriz de urina sintética por meio do uso de MCR-ALS acoplado com o método de adição de padrão. O método SERS-MCR-ALS mostrou- se adequado para resolver a sobreposição de bandas espectrais e compensar o efeito de matriz, o que permitiu a quantificação de ácido úrico em concentrações clinicamente relevantes. Neste sentido, o método proposto possui o potencial para ser implementado no diagnóstico precoce de pré-eclâmpsia diretamente no local
onde o paciente se encontra (point of care) e para a determinação de ácido úrico em outros fluídos biológicos com matrizes complexas (e.g. plasma ou soro sanguíneo).
O acoplamento sinérgico da técnica de ring oven e SERS (técnica ROP- SERS), proposto nesta tese, é uma excelente estratégia para melhorar o processo de amostragem e a sensibilidade comumente proporcionada por meio do uso de substratos de papel. A possibilidade de síntese in situ de GNPs em papel de filtro foi demonstrada pela primeira vez; entretanto, o controle do crescimento das mesmas e a formação de hot spots ainda precisa ser estudado. Em contraste, a deposição direta de GNPs na borda do anel de analito mostrou ser uma forma mais eficiente de obter sinais intensos e com boa repetibilidade. Além disso, essa estratégia possibilitou a redução do tempo de preparo de amostra e, ao mesmo tempo, a pré- concentração do analito, possibilitando o controle da sensibilidade. A técnica ROP- SERS foi utilizada com sucesso em duas aplicações bioanalíticas: o monitoramento de bases purínicas em DNA e a determinação de adenosina em urina. Na primeira aplicação, o método de adição de padrão e o uso de padrões internos permitiram compensar o efeito de matriz e obter medidas com uma alta repetibilidade. Assim, a técnica ROP-SERS mostrou-se adequada para o monitoramento de bases purínicas e a proporção (C+G)/(A+T) em DNA e, consequentemente, para a prevenção de uma grande variedade de doenças relacionadas com a degeneração do DNA. Na segunda aplicação, a adenosina, considerada como um potencial biomarcador de câncer em urina, foi quantificada em concentrações fisiologicamente relevantes por meio do uso de MCR-ALS acoplado com o método de adição de padrão. Assim, acredita-se que o método ROP-SERS-MCR-ALS proposto poderia ser implementado no diagnóstico precoce e não invasivo de câncer e na detecção de outras moléculas biologicamente relevantes.
Portanto, as aplicações bioanalíticas desenvolvidas neste trabalho indicam que a espectroscopia Raman intensificada por superfície pode ser utilizada de forma eficiente no cuidado da saúde humana, empregando apenas papel como plataforma analítica.
REFERÊNCIAS
[1] M. Daniels, T. Donilon, T.J. Bollyky, The Emerging Global Health Crisis: Noncommunicable Diseases in Low- and Middle-Income Countries. Independent Task Force Report No. 72, Council on Foreign Relations, 2014. [2] L. Chen, T. Evans, S. Anand, J.I. Boufford, H. Brown, M. Chowdhury, M.
Cueto, L. Dare, G. Dussault, G. Elzinga, E. Fee, D. Habte, P. Hanvoravongchai, M. Jacobs, C. Kurowski, S. Michael, A. Pablos-Mendez, N. Sewankambo, G. Solimano, B. Stilwell, A. de Waal, S. Wibulpolprasert, Human resources for health: overcoming the crisis, Lancet. 364 (2004) 1984–1990. [3] R.A. Shaw, H.H. Mantsch, Infrared Spectroscopy in Clinical and Diagnostic
Analysis, in: Encycl. Anal. Chem., John Wiley & Sons, Ltd, Chichester, UK, 2006: pp. 1–20.
[4] G.J. Thomas, Raman spectroscopy of protein and nucleic acid assemblies, Annu. Rev. Biophys. Biomol. Struct. 28 (1999) 1–27.
[5] J.L. West, N.J. Halas, Engineered nanomaterials for biophotonics applications: Improving sensing, imaging, and therapeutics, Annu. Rev. Biomed. Eng. 5 (2003) 285–292.
[6] J. Ferraro, Introductory Raman Spectroscopy, Academic Press, Cambridge, MA, 2002.
[7] E. Smith, G. Dent, Modern Raman Spectroscopy – A Practical Approach, John Wiley & Sons, Ltd, Hoboken, NJ, 2005.
[8] A.C. Ferrari, D.M. Basko, Raman spectroscopy as a versatile tool for studying the properties of graphene, Nat. Nanotechnol. 8 (2013) 235–246.
[9] X.J. Gu, W. Jiang, Characterization of polymorphic forms of fluconazole using fourier transform Raman spectroscopy, J. Pharm. Sci. 84 (1995) 1438–1441. [10] S. Bresson, D. Rousseau, S. Ghosh, M. El Marssi, V. Faivre, Raman
spectroscopy of the polymorphic forms and liquid state of cocoa butter, Eur. J. Lipid Sci. Technol. 113 (2011) 992–1004.
[11] M.K. Nieuwoudt, S.E. Holroyd, C.M. McGoverin, M.C. Simpson, D.E. Williams, Raman spectroscopy as an effective screening method for detecting adulteration of milk with small nitrogen-rich molecules and sucrose, J. Dairy
Sci. 99 (2016) 2520–2536.
[12] R.H. Clarke, W.M. Chung, Q. Wang, S. DeJesus, U. Sexerman, Determination of aromatic composition of fuels by laser Raman spectroscopy, J. Raman Spectrosc. 22 (1991) 79–82.
[13] M.R. Almeida, C.H.V. Fidelis, L.E.S. Barata, R.J. Poppi, Classification of Amazonian rosewood essential oil by Raman spectroscopy and PLS-DA with reliability estimation, Talanta. 117 (2013) 305–311.
[14] C.J. Strachan, T. Rades, K.C. Gordon, J. Rantanen, Raman spectroscopy for quantitative analysis of pharmaceutical solids, J. Pharm. Pharmacol. 59 (2007) 179–192.
[15] A.S. Haka, K.E. Shafer-Peltier, M. Fitzmaurice, J. Crowe, R.R. Dasari, M.S. Feld, Diagnosing breast cancer by using Raman spectroscopy, Proc. Natl. Acad. Sci. 102 (2005) 12371–12376.
[16] P. Vítek, E.M.A. Ali, H.G.M. Edwards, J. Jehlička, R. Cox, K. Page, Evaluation of portable Raman spectrometer with 1064 nm excitation for geological and forensic applications, Spectrochim. Acta Part A. 86 (2012) 320–327.
[17] E.L. Izake, Forensic and homeland security applications of modern portable Raman spectroscopy, Forensic Sci. Int. 202 (2010) 1–8.
[18] J. Jehlicka, P. Vitek, H.G.M. Edwards, M. Hargreaves, T. Capoun, Application of portable Raman instruments for fast and non-destructive detection of minerals on outcrops, Spectrochim. Acta Part A. 73 (2009) 410–419.
[19] R. Aroca, Surface-Enhanced Vibrational Spectroscopy, John Wiley & Sons, Ltd, Chichester, UK, 2006.
[20] D.S. Moore, R.J. Scharff, Portable Raman explosives detection, Anal. Bioanal. Chem. 393 (2009) 1571–1578.
[21] B. Robert, Resonance Raman spectroscopy, Photosynth. Res. 101 (2009) 147–155.
[22] M. Fleischmann, P.J. Hendra, A.J. McQuillan, Raman spectra of pyridine adsorbed at a silver electrode, Chem. Phys. Lett. 26 (1974) 163–166.
[23] D.L. Jeanmaire, R.P. Van Duyne, Surface Raman spectroelectrochemistry, J. Electroanal. Chem. Interfacial Electrochem. 84 (1977) 1–20.
[24] M.G. Albrecht, J.A. Creighton, Anomalously intense Raman spectra of pyridine at a silver electrode, J. Am. Chem. Soc. 99 (1977) 5215–5217.
[25] P.G. Etchegoin, E.C. Le Ru, Basic Electromagnetic Theory of SERS, in: Surface Enhanced Raman Spectroscopy, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2010: pp. 1–37.
[26] S.-Y. Ding, E.-M. You, Z.-Q. Tian, M. Moskovits, Electromagnetic theories of surface-enhanced Raman spectroscopy, Chem. Soc. Rev. 46 (2017) 4042– 4076.
[27] S.M. Morton, L. Jensen, Understanding the molecule-surface chemical coupling in SERS., J. Am. Chem. Soc. 131 (2009) 4090–4098.
[28] B.N.J. Persson, K. Zhao, Z. Zhang, Chemical Contribution to Surface- Enhanced Raman Scattering, Phys. Rev. Lett. 96 (2006) 207401.
[29] P.L. Stiles, J.A. Dieringer, N.C. Shah, R.P. Van Duyne, Surface-Enhanced Raman Spectroscopy, Annu. Rev. Anal. Chem. 1 (2008) 601–626.
[30] K. Hering, D. Cialla, K. Ackermann, T. Dörfer, R. Möller, H. Schneidewind, R. Mattheis, W. Fritzsche, P. Rösch, J. Popp, SERS: a versatile tool in chemical and biochemical diagnostics, Anal. Bioanal. Chem. 390 (2008) 113–124.
[31] M. Fan, G.F.S. Andrade, A.G. Brolo, A review on the fabrication of substrates for surface enhanced Raman spectroscopy and their applications in analytical chemistry, Anal. Chim. Acta. 693 (2011) 7–25.
[32] K. Kneipp, H. Kneipp, R. Manoharan, E.B. Hanlon, I. Itzkan, R.R. Dasari, M.S. Feld, Extremely Large Enhancement Factors in Surface-Enhanced Raman Scattering for Molecules on Colloidal Gold Clusters, Appl. Spectrosc. 52 (1998) 1493–1497.
[33] X.M. Lin, Y. Cui, Y.H. Xu, B. Ren, Z.Q. Tian, Surface-enhanced Raman spectroscopy: Substrate-related issues, Anal. Bioanal. Chem. 394 (2009) 1729–1745.
[34] S.L. Kleinman, R.R. Frontiera, A.-I. Henry, J.A. Dieringer, R.P. Van Duyne, Creating, characterizing, and controlling chemistry with SERS hot spots, Phys. Chem. Chem. Phys. 15 (2013) 21–36.
[35] A. Hakonen, P.O. Andersson, M. Stenbæk Schmidt, T. Rindzevicius, M. Käll, Explosive and chemical threat detection by surface-enhanced Raman scattering: A review, Anal. Chim. Acta. 893 (2015) 1–13.
[36] N.A.A. Hatab, J.M. Oran, M.J. Sepaniak, Surface-enhanced Raman spectroscopy substrates created via electron beam lithography and
nanotransfer printing, ACS Nano. 2 (2008) 377–385.
[37] P. Mosier-Boss, Review of SERS Substrates for Chemical Sensing, Nanomaterials. 7 (2017) 142.
[38] L. Polavarapu, L.M. Liz-Marzán, Towards low-cost flexible substrates for nanoplasmonic sensing, Phys. Chem. Chem. Phys. 15 (2013) 5288.
[39] Y.H. Ngo, D. Li, G.P. Simon, G. Garnier, Gold nanoparticle-paper as a three- dimensional surface enhanced Raman scattering substrate, Langmuir. 28 (2012) 8782–8790.
[40] Y. Zhu, M. Li, D. Yu, L. Yang, A novel paper rag as ‘D-SERS’ substrate for detection of pesticide residues at various peels, Talanta. 128 (2014) 117–124. [41] H. Torul, H. Çiftçi, D. Çetin, Z. Suludere, I.H. Boyacı, U. Tamer, Paper
membrane-based SERS platform for the determination of glucose in blood samples, Anal. Bioanal. Chem. 407 (2015) 8243–8251.
[42] Y. Zhu, L. Zhang, L. Yang, Designing of the functional paper-based surface- enhanced Raman spectroscopy substrates for colorants detection, Mater. Res. Bull. 63 (2015) 199–204.
[43] L.F. Sallum, F.L.F. Soares, J.A. Ardila, R.L. Carneiro, Optimization of SERS scattering by Ag-NPs-coated filter paper for quantification of nicotinamide in a cosmetic formulation, Talanta. 118 (2014) 353–358.
[44] C.-C. Lin, C. Lin, C. Kao, C.-H. Hung, High efficiency SERS detection of clinical microorganism by AgNPs-decorated filter membrane and pattern recognition techniques, Sensors Actuators B Chem. 241 (2017) 513–521.
[45] S.E.J. Bell, A. Stewart, Quantitative SERS Methods, in: Surface Enhanced Raman Spectroscopy, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2010: pp. 71–86.
[46] E. Le Ru, P. Etchegoin, Principles of Surface-Enhanced Raman Spectroscopy, Elsevier Science, 2008.
[47] B. Sharma, P. Bugga, L.R. Madison, A.I. Henry, M.G. Blaber, N.G. Greeneltch, N. Chiang, M. Mrksich, G.C. Schatz, R.P. Van Duyne, Bisboronic acids for selective, physiologically relevant direct glucose sensing with surface- enhanced Raman spectroscopy, J. Am. Chem. Soc. 138 (2016) 13952–13959. [48] V. Ranc, Z. Markova, M. Hajduch, R. Prucek, L. Kvitek, J. Kaslik, K. Safarova,
determination of dopamine in an artificial cerebrospinal fluid and a mouse striatum using Fe3O4/Ag nanocomposite, Anal. Chem. 86 (2014) 2939–2946. [49] A.B. Zrimsek, A. Henry, R.P. Van Duyne, Single molecule surface-enhanced
Raman spectroscopy without nanogaps, J. Phys. Chem. Lett. 4 (2013) 3206– 3210.
[50] T. Dadosh, J. Sperling, G.W. Bryant, R. Breslow, T. Shegai, M. Dyshel, G. Haran, I. Bar-Joseph, Plasmonic control of the shape of the Raman spectrum of a single molecule in a silver nanoparticle dimer, ACS Nano. 3 (2009) 1988– 1994.
[51] M.V. Cañamares, C. Chenal, R.L. Birke, J.R. Lombardi, DFT, SERS, and single-molecule SERS of crystal violet, J. Phys. Chem. C. 112 (2008) 20295– 20300.
[52] W.A. Hassanain, E.L. Izake, A. Sivanesan, G.A. Ayoko, Towards interference free HPLC-SERS for the trace analysis of drug metabolites in biological fluids, J. Pharm. Biomed. Anal. 136 (2017) 38–43.
[53] D.P. Cowcher, R. Jarvis, R. Goodacre, Quantitative online liquid chromatography-surface-enhanced Raman scattering of purine vases, Anal. Chem. 86 (2014) 9977–9984.
[54] R.G. Brereton, J. Jansen, J. Lopes, F. Marini, A. Pomerantsev, O. Rodionova, J.M. Roger, B. Walczak, R. Tauler, Chemometrics in analytical chemistry—part I: history, experimental design and data analysis tools, Anal. Bioanal. Chem. 409 (2017) 5891–5899.
[55] H.-F. Köhn, L.J. Hubert, Hierarchical Cluster Analysis, in: Wiley StatsRef Stat. Ref. Online, John Wiley & Sons, Ltd, Chichester, UK, 2015: pp. 1–13.
[56] S. Wold, K. Esbensen, P. Geladi, Principal component analysis, Chemom. Intell. Lab. Syst. 2 (1987) 37–52.
[57] M.A. Sharaf, D.L. Illman, B.R. Kowalski, Chemometrics, John Wiley & Sons, Hoboken, NJ, 1986.
[58] G. Ragno, G. Ioele, A. Risoli, Multivariate calibration techniques applied to the spectrophotometric analysis of one-to-four component systems, Anal. Chim. Acta. 512 (2004) 173–180.
[59] O. Alharbi, Y. Xu, R. Goodacre, Simultaneous multiplexed quantification of nicotine and its metabolites using surface enhanced Raman scattering,
Analyst. 139 (2014) 4820–4827.
[60] R.P. Cogdill, P. Dardenne, Least-squares support vector machines for chemometrics: An introduction and evaluation, J. Near Infrared Spectrosc. 12 (2004) 93–100.
[61] S. Wold, M. Sjöström, L. Eriksson, PLS-regression: a basic tool of chemometrics, Chemom. Intell. Lab. Syst. 58 (2001) 109–130.
[62] T. Azzouz, R. Tauler, Application of multivariate curve resolution alternating least squares (MCR-ALS) to the quantitative analysis of pharmaceutical and agricultural samples, Talanta. 74 (2008) 1201–1210.
[63] D. Ballabio, V. Consonni, Classification tools in chemistry. Part 1: Linear models. PLS-DA, Anal. Methods. 5 (2013) 3790–3798.
[64] N.F. Pérez, J. Ferré, R. Boqué, Calculation of the reliability of classification in discriminant partial least-squares binary classification, Chemom. Intell. Lab. Syst. 95 (2009) 122–128.
[65] B.G. Botelho, N. Reis, L.S. Oliveira, M.M. Sena, Development and analytical validation of a screening method for simultaneous detection of five adulterants in raw milk using mid-infrared spectroscopy and PLS-DA, Food Chem. 181 (2015) 31–37.
[66] A. de Juan, J. Jaumot, R. Tauler, Multivariate Curve Resolution (MCR). Solving the mixture analysis problem, Anal. Methods. 6 (2014) 4964–4976.
[67] J. Jaumot, A. de Juan, R. Tauler, MCR-ALS GUI 2.0: New features and applications, Chemom. Intell. Lab. Syst. 140 (2015) 1–12.
[68] W. Windig, Spectral data files for self-modeling curve resolution with examples using the Simplisma approach, Chemom. Intell. Lab. Syst. 36 (1997) 3–16. [69] M.B. Mamián-López, R.J. Poppi, Standard addition method applied to the
urinary quantification of nicotine in the presence of cotinine and anabasine using surface enhanced Raman spectroscopy and multivariate curve resolution, Anal. Chim. Acta. 760 (2013) 53–59.
[70] T.M. Wassenaar, Bacteria: The Benign, the Bad, and the Beautiful, John Wiley & Sons, Hoboken, NJ, 2012.
[71] A.S. Evans, H.A. Feldman, Bacterial Infections of Humans: Epidemiology and Control, Springer, Verlag, NJ, 1982.
https://pt.wikipedia.org/wiki/Ciclo_do_nitrogênio#/media/File:Nitrogen_Cycle_pt .png (acessado em 15/08/2018).
[73] J.M. Janda, S.L. Abbott, 16S rRNA Gene sequencing for bacterial identification in the diagnostic laboratory: Pluses, perils, and pitfalls, J. Clin. Microbiol. 45 (2007) 2761–2764.
[74] P.C.Y. Woo, S.K.P. Lau, J.L.L. Teng, H. Tse, K.-Y. Yuen, Then and now: use of 16S rDNA gene sequencing for bacterial identification and discovery of novel bacteria in clinical microbiology laboratories, Clin. Microbiol. Infect. 14 (2008) 908–934.
[75] S. Sauer, A. Freiwald, T. Maier, M. Kube, R. Reinhardt, M. Kostrzewa, K. Geider, Classification and Identification of Bacteria by Mass Spectrometry and Computational Analysis, PLoS One. 3 (2008) e2843.
[76] I.A. Ratiu, V. Bocos-Bintintan, A. Patrut, V.H. Moll, M. Turner, C.L.P. Thomas, Discrimination of bacteria by rapid sensing their metabolic volatiles using an aspiration-type ion mobility spectrometer (a-IMS) and gas chromatography- mass spectrometry GC-MS, Anal. Chim. Acta. 982 (2017) 209–217.
[77] A. Sengupta, M. Mujacic, E.J. Davis, Detection of bacteria by surface- enhanced Raman spectroscopy, Anal. Bioanal. Chem. 386 (2006) 1379–1386. [78] W.R. Premasiri, J.C. Lee, A. Sauer-Budge, R. Théberge, C.E. Costello, L.D.
Ziegler, The biochemical origins of the surface-enhanced Raman spectra of bacteria: a metabolomics profiling by SERS, Anal. Bioanal. Chem. 408 (2016) 4631–4647.
[79] J. Turkevich, P.C. Stevenson, J. Hillier, A study of the nucleation and growth processes in the synthesis of colloidal gold, Discuss. Faraday Soc. 11 (1951) 55–75.
[80] C.H. Lee, L. Tian, S. Singamaneni, Paper-based SERS swab for rapid trace detection on real-world surfaces, ACS Appl. Mater. Interfaces. 2 (2010) 3429– 3435.
[81] Y.H. Ngo, D. Li, G.P. Simon, G. Garnier, Effect of cationic polyacrylamides on the aggregation and SERS performance of gold nanoparticles-treated paper, J. Colloid Interface Sci. 392 (2013) 237–246.
[82] W.W. Yu, I.M. White, Inkjet printed surface enhanced Raman spectroscopy array on cellulose paper, Anal. Chem. 82 (2010) 9626–9630.
[83] W.-L.-J. Hasi, X. Lin, X.-T. Lou, S. Lin, F. Yang, D.-Y. Lin, Z.-W. Lu, Chloride ion-assisted self-assembly of silver nanoparticles on filter paper as SERS substrate, Appl. Phys. A. 118 (2015) 799–807.
[84] D.M. Carty, C. Delles, A.F. Dominiczak, Novel biomarkers for predicting preeclampsia, Trends Cardiovasc. Med. 18 (2008) 186–194.
[85] D.-H. Kang, A role for uric acid in the progression of renal disease, J. Am. Soc. Nephrol. 13 (2002) 2888–2897.
[86] L. Duley, The global impact of pre-eclampsia and eclampsia, Semin. Perinatol. 33 (2009) 130–137.
[87] L.K. Wagner, Diagnosis and management of preeclampsia, Am. Fam. Physician. 70 (2004) 2317–2324.
[88] C.S. Buhimschi, E.R. Norwitz, E. Funai, S. Richman, S. Guller, C.J. Lockwood, I. a. Buhimschi, Urinary angiogenic factors cluster hypertensive disorders and identify women with severe preeclampsia, Am. J. Obstet. Gynecol. 192 (2005) 734–741.
[89] E. Akyilmaz, A biosensor based on urate oxidase–peroxidase coupled enzyme system for uric acid determination in urine, Talanta. 61 (2003) 73–79.
[90] S.M.U. Ali, Z.H. Ibupoto, M. Kashif, U. Hashim, M. Willander, A potentiometric indirect uric acid sensor based on ZnO nanoflakes and immobilized uricase, Sensors. 12 (2012) 2787–2797.
[91] Y. Yue-dong, Simultaneous determination of creatine, uric ccid, creatinine and hippuric acid in urine by high performance liquid chromatography, Biomed. Chromatogr. 12 (1998) 47–49.
[92] L. Zhao, J. Blackburn, C.L. Brosseau, Quantitative detection of uric acid by electrochemical-surface enhanced Raman spectroscopy using a multilayered Au/Ag substrate, Anal. Chem. 87 (2015) 441–447.
[93] M. Ringler, A. Schwemer, M. Wunderlich, A. Nichtl, K. Kürzinger, T.A. Klar, J. Feldmann, Shaping emission spectra of fluorescent molecules with single plasmonic nanoresonators, Phys. Rev. Lett. 100 (2008) 203002.
[94] Y. Xu, Electromagnetic scattering by an aggregate of spheres, Appl. Opt. 34 (1995) 4573-4588.
[95] P.B. Johnson, R.W. Christy, Optical Constants of the Noble Metals, Phys. Rev. B. 6 (1972) 4370–4379.
[96] T. Brooks, C.W. Keevil, A simple artificial urine for the growth of urinary pathogens, Lett. Appl. Microbiol. 24 (1997) 203–206.
[97] B.R. Shmaefsky, How- To-Do-It Artificial Urine for Laboratory Testing, Am. Biol. Teach. 52 (1990) 170–172.
[98] R.D. Deegan, O. Bakajin, T.F. Dupont, G. Huber, S.R. Nagel, T.A. Witten, Capillary flow as the cause of ring stains from dried liquid drops, Nature. 389 (1997) 827–829.
[99] US Department of Health and Human Services, Regulations Implementing the Clinical Laboratory Improvement Amendments of 1988 (CLIA), Final Rule. (1992) 7002–7086.
[100] J. Saurina, C. Leal, R. Compañó, M. Granados, M.D. Prat, R. Tauler, Estimation of figures of merit using univariate statistics for quantitative second- order multivariate curve resolution, Anal. Chim. Acta. 432 (2001) 241–251. [101] R. Carabias-Martı́nez, E. Rodrı́guez-Gonzalo, B. Moreno-Cordero, J. Pérez-
Pavón, C. Garcı́a-Pinto, E. Fernández Laespada, Surfactant cloud point extraction and preconcentration of organic compounds prior to chromatography and capillary electrophoresis, J. Chromatogr. A. 902 (2000) 251–265.
[102] M. Rezaee, Y. Assadi, M.-R. Milani Hosseini, E. Aghaee, F. Ahmadi, S. Berijani, Determination of organic compounds in water using dispersive liquid- liquid microextraction., J. Chromatogr. A. 1116 (2006) 1–9.
[103] L. Maldaner, I.C.S.F. Jardim, Determination of some organic contaminants in water samples by solid-phase extraction and liquid chromatography-tandem mass spectrometry, Talanta. 100 (2012) 38–44.
[104] J. Cortez, C. Pasquini, Ring-oven based preconcentration technique for microanalysis: Simultaneous determination of Na, Fe, and Cu in fuel ethanol by laser induced breakdown spectroscopy, Anal. Chem. 85 (2013) 1547–1554. [105] H. Weisz, Microanalysis by Ring-Oven Technique, 2nd ed., Pergamon, New
York, 1970.
[106] F. Feigl, Organic spot test analysis, Anal. Chem. 27 (1955) 1315–1318.
[107] P.W. West, A.J. Llacer, C. Cimerman, Contributions to the ring oven technique, Microchim. Acta. 50 (1962) 1165–1168.
[108] F. Ordoveza, P.W. West, Microdetermination of caffeine using the ring oven technique, Anal. Chim. Acta. 30 (1964) 227–233.
[109] N.G. Buckman, J. Hill, R.J. Magee, Identification and determination of microgram amounts of phenol and chlorophenols by the ring oven technique, Microchem. J. 478 (1983) 470–478.
[110] L.R. Brito, M.P.F. da Silva, J.J.R. Rohwedder, C. Pasquini, F.A. Honorato, M.F. Pimentel, Determination of detergent and dispensant additives in gasoline by ring-oven and near infrared hypespectral imaging, Anal. Chim. Acta. 863 (2015) 9–19.
[111] A. Pietrzyk, S. Suriyanarayanan, W. Kutner, R. Chitta, M.E. Zandler, F. D’Souza, Molecularly imprinted polymer (MIP) based piezoelectric microgravimetry chemosensor for selective determination of adenine, Biosens. Bioelectron. 25 (2010) 2522–2529.
[112] P. Cekan, S.T. Sigurdsson, Identification of single-base mismatches in duplex DNA by EPR spectroscopy, J. Am. Chem. Soc. 131 (2009) 18054–18056. [113] Y. Badralmaa, V. Natarajan, Impact of the DNA extraction method on 2-LTR
DNA circle recovery from HIV-1 infected cells, J. Virol. Methods. 193 (2013) 184–189.
[114] H. Fan, F.Q. Yang, S.P. Li, Determination of purine and pyrimidine bases in natural and cultured Cordyceps using optimum acid hydrolysis followed by high performance liquid chromatography, J. Pharm. Biomed. Anal. 45 (2007) 141– 144.
[115] M. Haunschmidt, W. Buchberger, C.W. Klampfl, Investigations on the migration behaviour of purines and pyrimidines in capillary electromigration techniques with UV detection and mass spectrometric detection, J. Chromatogr. A. 1213 (2008) 88–92.
[116] M.U. Anu Prathap, R. Srivastava, B. Satpati, Simultaneous detection of guanine, adenine, thymine, and cytosine at polyaniline/MnO2 modified electrode, Electrochim. Acta. 114 (2013) 285–295.
[117] N.A. Mautjana, D.W. Looi, J.R. Eyler, A. Brajter-Toth, Sensitivity of positive ion mode electrospray ionization mass spectrometry (ESI MS) in the analysis of purine bases in ESI MS and on-line electrochemistry ESI MS (EC/ESI MS), Electrochim. Acta. 55 (2009) 52–58.
[118] Biophilia. Hanging On For Dear Life.
em 15/08/2018).
[119] V. Verdolino, R. Cammi, B.H. Munk, H.B. Schlegel, Calculation of pKa values of nucleobases and the guanine oxidation products guanidinohydantoin and spiroiminodihydantoin using density functional theory and a polarizable continuum model, J. Phys. Chem. B. 112 (2008) 16860–16873.
[120] C. Carrillo-Carrión, S. Armenta, B.M. Simonet, M. Valcárcel, B. Lendl, Determination of pyrimidine and purine bases by reversed-phase capillary liquid chromatography with at-line surface-enhanced Raman spectroscopic detection employing a novel SERS substrate based on ZnS/CdSe silver– quantum dots, Anal. Chem. 83 (2011) 9391–9398.
[121] J.N. Davidson, The Biochemistry of the Nucleic Acids, seventh ed, Cox & Nyman, Norfolk, UK, 1972.
[122] D.W. Kufe, R.E. Pollock, R.R. Weichselbaum, R.C. Bast, T.S. Gansler, J.F. Holland, Cancer Medicine, 6th ed., BC Decker, Hamilton (ON), Canada, 2003. [123] World Health Organization (WHO), Cancer, (n.d.).
http://www.who.int/mediacentre/ factsheets/fs297/en/ (acessado em 15/08/2018).
[124] Cancer. Tipos de câncer mais comuns nas mulheres e nos homens. https://saude.abril.com.br/medicina/os-tipos-de-cancer-mais-comuns-nas- mulheres-e-nos-homens/ (acessado em 15/08/2018).
[125] K. Bensalah, F. Montorsi, S.F. Shariat, Challenges of cancer biomarker profiling, Eur. Urol. 52 (2007) 1601–1609.
[126] J. Spychala, Tumor-promoting functions of adenosine, Pharmacol. Ther. 87 (2000) 161–173.
[127] T. Yang, X. Guo, Y. Wu, H. Wang, S. Fu, Y. Wen, H. Yang, Facile and label- free detection of lung cancer biomarker in urine by magnetically assisted surface-enhanced Raman scattering, ACS Appl. Mater. Interfaces. 6 (2014) 20985–20993.
[128] W.-Y. Hsu, C.-J. Chen, Y.-C. Huang, F.-J. Tsai, L.-B. Jeng, C.-C. Lai, Urinary nucleosides as biomarkers of breast, colon, lung, and gastric cancer in Taiwanese, PLoS One. 8 (2013) e81701.
[129] T. Yamamoto, Y. Moriwaki, S. Takahashi, T. Fujita, Z. Tsutsumi, J. Yamakita, K. Shimizu, M. Shioda, S. Ohta, K. Higashino, Determination of adenosine and
deoxyadenosine in urine by high-performance liquid chromatography with