A novel visible light photoelectrochemical aptasensor for detection of bisphenol A

BPA (bisphenol A) is an organic compound that is widely used to make epoxy and polycarbonate resins [1]. Epoxy resins are used extensively for many applications such as industrial flooring, adhesives, sealants, can coating and printed circuit boards [2]. Polycarbonate resins are light-weight, high performance plastics that are mainly used to make medical equipment, water bottles, digital media (e.g. CDs and DVDs) and some reusable food-contact containers [3]. The safety of BPA has been extensively studied. Numerous scientific studies and government assessment show that human exposure to BPA which is released into environment from manufacturing processes or plastic products under severe conditions (e.g. acidic, basic and other physical conditions) can affect the functions of brain, thyroid, ovary, reproductive organs and increasing the rate of cancer [4]. Therefore, it is important to determine the BPA level in food samples and environment.Photoelectrochemical (PEC) detection represents a novel and dynamically developing analytical technique which has attracted substantial research scrutiny for its satisfactory analytical performances [5]. PEC detection possesses potential merits than traditional electrochemical methods because of its total separation and different energy form of the excitatil (photocurrent). Different from electrochemical analysis, PEC detection system requires a photoactive working electrode to produce photocurrent signal under photoirradiation.In this study, Ag-gC3N4 nanocomposite was used as novel photoactive materials to establish the PEC aptasensor for the detection of BPA. Here, first of all, the Ag-gC3N4 nanocomposite was immobilized on the surface of FTO electrode. Then the electrode was electrodeposited with gold nanoparticles (Au NPs). In the next step, SH-aptamer was adsorbed on the Ag-gC3N4/Au NPs nanocomposite through S-Au bond. Under optimal conditions, the proposed sensor showed a low detection limit and good selectivity for target analysis. The potential applicability of the PEC aptasensor was confirmed by detecting BPA in real samples.