Enzymatic polyphenol index biosensor based on Graphene nanoplatelets decorated with MnO2 Nanoparticles. Preparation, characterization and Analytical application
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A nanocomposite formed from graphene nanoplatelets (GNP) and manganese oxide (MnO2) nanoparticles (GNP/MnO2) was proposed as a novel and suitable support for enzyme immobilisation. The performances of screen-printed carbon electrodes (SPCEs) was highly improved after modification with GNP/MnO2 (SPCE/GNP/MnO2). The polyphenol index biosensor was prepared by surface modification of SPCE/GNP/MnO2 with drop coating of the laccase (from Trametes Versicolor) and Nafion®. All electrochemical measurements were carried out in acetate buffer, pH=4.60. The developed laccase biosensor shows fast and reliable amperometric response toward caffeic acid, as model compound, at operating potential of +0.40 V (vs. Ag/AgCl), with a linear range from 5 μmol L-1 to 2.75 mmol L-1 (r2 = 0.9997), with detection limit of 2.38 μmol L-1. Moreover, effects of possible interfering compounds were investigated. The developed procedure was successfully applied for the determination of total polyphenol content in red a...nd white wine samples. In order to validate the proposed method, the polyphenol content in wine samples, under optimized parameters, was determined using a glassy carbon electrode. Recovery tests (95.7-97.5%) shows satisfactory accuracy and precision of the developed method, concluding that proposed construction of biosensor can offer fast, stable and reproducible determination of the polyphenol index.
Ključne reči:graphene nanoplatelets / manganese oxide / polyphenol index biosensor / total polyphenol content / wine samples
Izvor:Book of Abstracts - YISAC 2019 (26th Young Investigators’ Seminar on Analytical Chemistry), 2019, 38-
- University of Pardubice, 2019
- 26th Young Investigators’ Seminar on Analytical Chemistry, June 24 – 27, 2019, Pardubice, Czech Republic