Synthesis of NiO-Doped ZnO Nanoparticle-Decorated Reduced Graphene Oxide Nanohybrid for Highly Sensitive and Selective Electrochemical Sensing of Bisphenol A in Aqueous Samples

Bisphenol A (BPA) is broadly used in the plastic industry and has several health effects, especially on the brain and prostate gland of fetuses. BPA is a major environmental pollutant that drains into bodies of water and leaches from food packaging. Since it is a known endocrine disruptor, its extensive release into the environment is a serious concern. Thus, regular monitoring of BPA through a reliable and sensitive method is a strategy that can help alleviate its impact. To tackle this issue, an excellent conductive material based on a NiO/ZnO/rGO nanohybrid was used as an electrocatalyst to determine BPA in drinking water samples. The engineered material was characterized through XRD, EDX, and SEM. The EDX mapping was also used to examine the purity, surface texture, and focused elemental composition of the NiO/ZnO/rGO nanohybrid. The average size of the prepared material was calculated as 43.7 nm, which confirmed the nanometric size of the engineered nanohybrid material. The conductive behavior of the fabricated sensor NiO/ZnO/rGO/PtE was examined through electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The modified sensor revealed an excellent conductive nature with ohmic resistance calculated to be 412 ω, which is lower than that of the bare electrode and GO/PtE (3628 and 2239 ω, respectively). Under optimal parameters, the fabricated sensor showed excellent response for BPA. With a linear dynamic range of 0.07-30 μM, NiO/ZnO/rGO/PtE manifested the lowest possible detection limit found (4.0 nM). The analytical applicability of the proposed sensor was investigated in bottled and tap water. Furthermore, both the acceptable recovery values and anti-interference ability indicated the effectiveness and potential commercial utilization of NiO/ZnO/rGO/PtE. The recovery values for mineral and tap water were 97.0%, 99.0%, and 97.3% and 101%, 99.6%, and 98.7%, respectively.