Self-powered molecular imprinted photoelectrochemical sensing platform of sialic acid employing WO 3 /Bi 2 S 3 photoanode and CuInS 2 photocathode

A dual-photoelectrode molecular imprinted photoelectrochemical (PEC) sensor is first built for the determination of sialic acid (SA) without additional energy supply. Specifically, WO /Bi S heterojunction behaves as a photoanode to provide amplified and stable photocurrent for the PEC sensing platform, which is attributed to the matched energy levels of WO and Bi S promoting the electron transfer and improving photoelectric conversion properties. CuInS micro-flowers functionalized by molecularly imprinted polymers (MIPs) are served as photocathode to recognize SA, avoiding the deficiency of high production cost and poor stability from biological enzymes, aptamers, or antigen-antibodies. The inherent deviation between the Fermi level of the photoanode and the photocathode guarantees a spontaneous power supply for the PEC system. Benefiting from the photoanode and recognition elements, the as-fabricated PEC sensing platform has a strong anti-interference ability and high selectivity. Moreover, the PEC sensor displays a wide linear range of 1 nM-100 μM and a low detection limit of 7.1 × 10 M (S/N = 3) based on the relationship between photocurrent signal and SA concentration. Accordingly, this research provides a new and valuable approach to detecting various molecules.