Laccase Polyphenolic Biosensor Supported on MnO₂@GNP Decorated SPCE: Preparation, Characterization, and Analytical Application

Based on graphene nanoplatelets capability to build block composites, as well well-known electrochemical characteristic of the manganese oxide materials, in present research, a nanocomposite, formed from (GNP) and manganese(IV)-oxide (MnO2) nanoparticles, has been proposed novel convenient support for enzyme immobilization. Performance screen printed carbon electrodes (SPCEs) was significantly improved after their modification with GNP@MnO2 (SPCE/GNP@MnO2). The polyphenolic index biosensor prepared by applying drop coating technique using laccase Nafion®. Developed shows fast reliable amperometric response toward caffeic acid, model compound, at operating potential +0.40 V (vs Ag/AgCl), wide linear range detection limit 1.9 μmol l−1. procedure successfully applied determination indexes wine samples. Recovery tests indicate excellent accuracy precision method, concluding that can offer fast, accurate, precise index. More importantly, our results suggest great application real