Improved stability and altered selectivity of tyrosinase based graphite electrodes for detection of phenolic compounds

Nistor, C. E.; Emnéus, Jenny; Gorton, Lo; Ciucu, Anton Alexandru

doi:10.1016/s0003-2670(99)00071-9

Cited by 167 publications

(85 citation statements)

References 50 publications

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“…4, 2002 great variety of organs and tissues, primarily lungs, liver, kidneys and genito-urinary system. 5,6 Many phenols, especially chlorophenols, are known for their persistency in the environment and propensity for bioconcentration and biomagnification. 7 Several procedures have been developed for the determination of phenolic compounds, such as chromotographic techniques, fluorimetric and spectrophotometric methods.…”

Section: Introductionmentioning

confidence: 99%

“…7 Several procedures have been developed for the determination of phenolic compounds, such as chromotographic techniques, fluorimetric and spectrophotometric methods. 6,8 However, these techniques do not easily allow continuous monitoring in real samples. They are expensive, time-consuming, need skilled operators, and sometimes require preconcentration and extraction steps that increase the risk of samples loss.…”

Section: Introductionmentioning

confidence: 99%

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Electrochemical biosensor-based devices for continuous phenols monitoring in environmental matrices

Freire¹,

Durán²,

Kubota³

2002

J. Braz. Chem. Soc.

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Desenvolveu-se um método de análise em fluxo para a determinação contínua de compostos fenólicos em matrizes ambientais, usando-se uma membrana de diálise para amostragem e biossensores a base de lacase e tirosinase para a detecção destes compostos. A resposta dos biossensores frente a diferentes compostos fenólicos foi investigada. O biossensor a base de lacase mostrou uma alta sensibilidade para guaiacol e cloroguaiacol, enquanto que o biossensor de tirosinase foi mais sensível para fenol e clorofenol. Ambos os biossensores apresentaram respostas seletivas para concentrações destes compostos em níveis micromolares. Limites de detecção de 1,1 x 10 -7 mol L -1 para guaiacol e de 1,9 x 10 -7 mol L -1 para cloroguaiacol foram obtidos usando-se o biossensor a base de lacase. Empregando-se o biossensor a base de tirosinase obteve-se limites de detecção de 1,5 x 10 -7 mol L -1 para fenol e de 9,0 x 10 -8 mol L -1 para clorofenol. O método de análise em fluxo proposto apresentou um faixa linear de trabalho entre 1,0 mmol L -1 e 100,0 mmol L -1, nas condições operacionais otimizadas dos biossensores (biossensor a base de lacase: pH 5,0 e potencial de trabalho 0 mV vs Ag/AgCl; biossensor a base de tirosinase: pH 5,0 e potencial de trabalho 50 mV vs Ag/AgCl). Uma amostra real de efluente papeleiro foi analisada pelo sistema proposto e pelo método colorimétrico de referência e os resultados discutidos.A flow system method for continuous determination of phenolic compounds in environmental matrices was employed using a dialysis membrane sampler and laccase-and tyrosinase-based biosensors as detector. The biosensors response to different phenolic compounds was investigated. The laccase-based biosensor showed high sensitivity to guaiacol and chloroguaiacol, while the tyrosinase-based biosensor was more sensitive to phenol and chlorophenol. Both of the biosensors presented highly selective measurements of micromolar concentration of these compounds. Detection limits around 1.1 x 10 -7 mol L -1 for guaiacol and 1.9 x 10 -7 mol L -1 for chloroguaiacol could be estimated for the laccase-based biosensor. Using the tyrosinase-based biosensor detection limits of 1.5 x 10 -7 mol L -1 for phenol and 9.0 x 10 -8 mol L -1 for chlorophenol were observed. The proposed flow method presented a linear response range between 1.0 mmol L -1 and 100.0 mmol L -1 , in the optimized operational conditions (laccase-based biosensor: pH 5.0 and 0 mV vs Ag/AgCl as working potential; tyrosinase-based biosensor: pH 5.5 and 50 mV vs Ag/AgCl as working potential). Real paper mill effluent sample was analyzed by this system and by the reference colorimetric method and the results were discussed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrochemical biosensor-based devices for continuous phenols monitoring in environmental matrices

Freire¹,

Durán²,

Kubota³

2002

J. Braz. Chem. Soc.

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“…Um número considerável de poluentes orgânicos, que encontram-se largamente distribuídos no meio ambiente, possuem estrutura fenólica 1 . Fenóis e seus derivados, como clorofenóis e compostos aromáticos relacionados, são conhecidos devido a sua elevada toxicidade e por serem compostos comuns em efluentes industriais, oriundos das atividades de produção de: plásticos, corantes, tintas, drogas, antioxidantes, polímeros sintéticos, resinas, pesticidas, detergentes, desinfetantes, refinaria de óleo e principalmente de papel e celulose [1][2][3][4][5][6][7][8] .…”

Section: Introductionunclassified

“…Fenóis e seus derivados, como clorofenóis e compostos aromáticos relacionados, são conhecidos devido a sua elevada toxicidade e por serem compostos comuns em efluentes industriais, oriundos das atividades de produção de: plásticos, corantes, tintas, drogas, antioxidantes, polímeros sintéticos, resinas, pesticidas, detergentes, desinfetantes, refinaria de óleo e principalmente de papel e celulose [1][2][3][4][5][6][7][8] . Compostos fenólicos também estão largamente presentes na natureza como componentes naturais da madeira (lignina e tanino) e são responsáveis pelas propriedades organolépticas e cores de muitas frutas e flores 8 .…”

Section: Introductionunclassified

Biossensores amperométricos para determinação de compostos fenólicos em amostras de interesse ambiental

Rosatto¹,

Freire²,

Durán³

et al. 2001

Quím. Nova

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“…The K m,app value for the free enzyme in solution was estimated to be 240 µM using catechol as the substrate. 57 Nistor et al reported that K m,app for immobilized tyrosinase was 230 µM using catechol as the substrate, 58 and Morales et al and Reviejo et al reported that K m,app for immobilized tyrosinase was about 400 and 440 µM using phenol as the substrate. 59,60 Compared with these reported data the obtained K m,app values in this study are relatively large, it may be ascribed to the relatively strong immobilization conditions employed in this study (covalent vs. adsorption or graphite composite 59,60 ).…”

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confidence: 99%

Sensing Characteristics of Tyrosinase Immobilized and Tyrosinase, Laccase Co-immobilized Platinum Electrodes

2004

Bulletin of the Korean Chemical Society

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Tyrosinase was covalently immobilized on platinum electrode according to the method we developed for laccase (Bull. Korean Chem. Soc. 2002, 23(7), 385) and p-chlorophenol, p-cresol, and phenol could be detected with sensitivities of 334, 139 and 122 nA/µM and the detection limits of 1.0, 2.0, and 2.5 µM, respectively. The response time (t 90% ) is 3 seconds for p-chlorophenol, and 5 seconds for p-cresol and phenol. The optimal pHs of the sensor are in the range of 5.0−6.0. This sensor can tolerate at least 500 times repeated injections of pchlorophenol with retaining 80% of initial activity. In case of tyrosinase and laccase co-immobilized platinum electrode, the sensitivities are 560 nA/µM for p-phenylenediamine (PPD) and 195 nA/µM for p-chlorophenol, respectively. The sensitivity of the bi-enzyme sensor for PPD increases 70% compared to that of only laccase immobilized one, but the sensitivity for p-chlorophenol decreases 40% compared to that of only tyrosinase immobilized one. The sensitivity increase for the bi-enzyme sensor for PPD can be ascribed to the additional catalytic function of the co-immobilized tyrosinase. The sensitivity decrease for p-chlorophenol can be explained by the "blocking effect" of the co-immobilized laccase, which hinders the mass transport through the immobilized layer. If PPD was detected with the electrode that had been used for p-chlorophenol, the sensitivity decreased 20% compared to that of the electrode that had been used only for PPD. Similarly, if p-chlorophenol was detected with PPD detected electrode, the sensitivity also decreased 20%. The substrate-induced conformation changes of the enzymes in a confined layer may be responsible for the phenomena.

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Improved stability and altered selectivity of tyrosinase based graphite electrodes for detection of phenolic compounds

Cited by 167 publications

References 50 publications

Electrochemical biosensor-based devices for continuous phenols monitoring in environmental matrices

Electrochemical biosensor-based devices for continuous phenols monitoring in environmental matrices

Biossensores amperométricos para determinação de compostos fenólicos em amostras de interesse ambiental

Sensing Characteristics of Tyrosinase Immobilized and Tyrosinase, Laccase Co-immobilized Platinum Electrodes

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