Fabrication of a sensitive electrochemical sensor platform using reduced graphene oxide-molybdenum trioxide nanocomposite for BPA detection: An endocrine disruptor

Abstract

Bisphenol A (BPA) is a potential endocrine-disrupting compound (EDC) that has adversely affected human health and the environment. Thus, there is an urgent need to develop a convenient, highly sensitive, and accurate method to detect BPA. Herein, we have developed a very efficient, sensitive electrochemical BPA sensor utilizing reduced graphene oxide (rGO) and molybdenum trioxide nanoparticles (MoO3Nps) nanocomposite. The in situ synthesis of MoO3Nps onto the surface of rGO sheets was achieved through one-pot hydrothermal synthesis at a lower temperature where the chemical functionality and two-dimensional structure of rGO combined with MoO3Nps has provided an excellent platform for BPA detection. The synergistic effect between rGO and MoO3Nps can effectively utilize their larger active surface area, superior conductivity, and enhanced electrochemical behavior. The morphological, structural, and electrochemical changes of the rGO_MoO3Nps nanocomposite have been characterized through X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and electrochemical techniques. The thin films of rGO_MoO3Nps nanocomposite were fabricated using electrophoretic deposition on indium tin oxide coated glass. The proposed sensor rGO_MoO3Nps/ITO exhibited high sensitivity of 13.96 µA (log nM)−1 cm2, wider linear range (0.76 × 10−9 µM–0.820 µM), and lowest limit of detection (0.12 nM) achieved till now, in comparison to earlier nanocomposite based sensor platforms. Furthermore, the sensor displayed good selectivity towards BPA and has the application in real samples such as packaged water, canned cold drink, and processed milk. Thus, rGO_MoO3Nps nanocomposite could emerge as a promising material for the detection of other estrogenic substrates also.