A Visible-Light-Active CuS/MoS/BiWO Aptamer Sensitively Detects the Non-Steroidal Anti-Inflammatory Drug Diclofenac.

Diclofenac is a non-steroidal, anti-inflammatory drug and is clinically used for the treatment of osteoarthritis, non-articular rheumatism, etc. This research aimed to demonstrate the creation of an upgraded photoelectrochemical (PEC) aptamer sensor for detecting diclofenac (DCF) with high sensitivity. In this work, photoactive materials and bio-identification components served as visible-light-active CuS/MoS/BiWO heterostructures and aptamers, respectively. CuS and MoS/BiWO were combined to improve photocurrent responsiveness, which helped the structure of PEC aptasensors. Additionally, the one-pot synthesis of CuS/MoS/BiWO was ecologically beneficial. With these optimizations, the photocurrent response of aptamer/CS/CuS/MoS/BiWO exhibited linearity between 0.1 and 500 nM DCF. The detection limit was 0.03 nM (S/N = 3). These results suggest that the PEC sensing technique might produce an ultra-sensitive sensor with high selectivity and stability for DCF detection.