Environmentally benign and biocompatible sensing platform for electroanalytical determination of bisphenol A in the aquatic environment

Abstract

In this work, a facilely fabricated enzymatic biosensor composed of reduced graphene oxide (rGO), chitosan (Chi), and tyrosinase (Tyr) is developed for bisphenol A (BPA) determination. rGO with varying properties is obtained by different GO reduction routes. A trend correlating the sensing efficiency toward BPA with the population and distribution of surface oxygen functional groups on rGO is identified. Compared to other reducing routes, rGO fabricated using ascorbic acid, an environmentally benign reductant, has a lower amount of oxidation debris and higher contents of carboxyl groups. The increased content of carboxyl carbon in ascorbic acid-reduced graphene oxide (AArGO) contributes to promoting amide linkage (i.e., formation of more N-(C=O) groups) with chitosan, benefitting the assembly with tyrosinase to enhance BPA determination performance. The proposed Tyr/Chi/AArGO-modified electrodes serve to benefit rational designs of graphene-based nanocomposites for BPA determination and realize an environmentally benign, biocompatible, and facilely fabricated sensing platform for emerging contaminants in the aquatic environment.