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Fabrication of an Amperometric Flow-Injection Microfluidic Biosensor Based on Laccase for In Situ Determination of Phenolic Compounds

We aim to develop an in situ microfluidic biosensor based on laccase from Trametes pubescens with flow-injection and amperometry as the transducer method. The enzyme was directly immobilized by potential step chronoamperometry, and the immobilization was studied using cyclic voltammetry and electroc...

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Detalles Bibliográficos
Autores principales: Gonzalez-Rivera, Juan C., Osma, Johann F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Hindawi Publishing Corporation 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4609777/
https://www.ncbi.nlm.nih.gov/pubmed/26509166
http://dx.doi.org/10.1155/2015/845261
Descripción
Sumario:We aim to develop an in situ microfluidic biosensor based on laccase from Trametes pubescens with flow-injection and amperometry as the transducer method. The enzyme was directly immobilized by potential step chronoamperometry, and the immobilization was studied using cyclic voltammetry and electrochemical impedance spectroscopy. The electrode response by amperometry was probed using ABTS and syringaldazine. A shift of interfacial electron transfer resistance and the electron transfer rate constant from 18.1 kΩ to 3.9 MΩ and 4.6 × 10(−2) cm s(−1) to 2.1 × 10(−4) cm s(−1), respectively, evidenced that laccase was immobilized on the electrode by the proposed method. We established the optimum operating conditions of temperature (55°C), pH (4.5), injection flow rate (200 µL min(−1)), and applied potential (0.4 V). Finally, the microfluidic biosensor showed better lower limit of detection (0.149 µM) and sensitivity (0.2341 nA µM(−1)) for ABTS than previous laccase-based biosensors and the in situ operation capacity.