Abstract

Determination of phenolic derivatives is very important in medical, food and environmental samplesbecause of their relevant significance in health care and pollution monitoring. Tyrosinase-based biosensorsare promising tools for this purpose because of several advantages with respect to currently useddetection methods.A key aspect in the development of a biosensor is the effective immobilization of the enzyme. In thiswork, ordered tyrosinase films on an optical transparent support were immobilized by a "layer-by-layer"(LbL) assembly, alternating the enzyme with the polycation polymer poly(dimethyldiallylammoniumchloride). As confirmed by UV-vis spectroscopy, the LbL deposition allowed a high loading of enzyme.The immobilized tyrosinase functionality was proven and its kinetic parameters were spectrophotometricallydetermined. The prepared biosensor was used to optically detect the o-diphenolic compoundl-3,4-dihydroxyphenyl-alanine (l-DOPA) and exhibited good repeatability and time stability. The sensingproperties of the system were studied by means of both absorption and fluorescence spectroscopy.The bioassay based on the absorbance measurements gave a LOD of 23M and a linear response up to350M. The bioassay based on the fluorescence measurements gave a LOD of 3Mand a linear responsein the range of tens of micromolar (the exact value depends on the number of mushroom tyrosinaselayers). Biosensor sensitivity could be modulated varying the number of the immobilized enzyme layers.

Autore Pugliese

• Mallardi Antonia

Tutti gli autori

• Fiorentino D.; Gallone A.; Fiocco D.; Palazzo G.; Mallardi A.

Titolo volume/Rivista

Biosensors & bioelectronics

Anno di pubblicazione

2010

ISSN

0956-5663

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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