Poly(4-vinylphenylboronic acid) functionalized polypyrrole/graphene oxide nanosheets for simultaneous electrochemical determination of catechol and hydroquinone

Abstract

Novel poly(4-vinylphenylboronic acid) (P4VPBA) functionalized polypyrrole/graphene oxide (PPy/GO) nanosheets, which combined the advantages of GO, PPy and PBA groups, were successfully prepared by a simple polymerization of 4-vinylphenylboronic acid (4VPBA) on the surface of pre-treated PPy/GO containing vinyl groups. Because of the synergistic effects of GO with excellent 2D structures and large surface area, PPy with good electronic conductivity and PBA with high recognition capability, P4VPBA/PPy/GO modified glassy carbon electrode presented excellent electrochemical sensing capabilities toward catechol (CC) and hydroquinone (HQ) with good stability, high sensitivity and selectivity, especially giving a large anodic peak potential difference between CC and HQ enough to well distinguish and simultaneously determine the two dihydroxybenzene isomers in their mixture. It is found that PBA groups on the surface of P4VPBA/PPy/GO nanosheets played an essential role for the discrimination and simultaneous electrochemical determination of CC and HQ, which may be due to the selective formation of stable cyclic esters by the covalent interaction between PBA groups and related molecules with a cis-diol in an alkaline aqueous solution. Therefore, P4VPBA/PPy/GO nanosheets can act as a good electrode material for building a steady electrochemical sensor for detecting the two dihydroxybenzene isomers with high sensitivity and selectivity.