Scalable drop-casting construction of light-addressable photoelectrochemical biosensor on laser-induced graphene electrode arrays for high-throughput drug screening

A drop-casting method for the scalable construction of a solar cell-type light-addressable photoelectrochemical (PEC) sensor on commercial phenol resin (PR) plates is reported. The sensor was fabricated by laser writing of addressable laser-induced graphene (LIG) electrode arrays on PR plates with ring-disc dual-electrode cell configurations using a 405 nm laser machine. Beneficial from the good hydrophilicity of PR-based LIG and the excellent film formation of bismuth sulfide nanorods (Bi₂S₃ NRs), uniform Bi₂S₃ photovoltaic films can be reproducibly deposited onto the LIG disc photoanode array via drop casting modification, which show a sensitive photocurrent response toward thiocholine (TCl) when the ring cathode array was coated with Ag/AgCl. An acetylcholinesterase (AChE)-based PEC biosensor was therefore constructed by a similar drop-casting modification method. The resulting biosensor exhibits good sensitivity toward an AChE inhibitor, i.e., galantamine hydrobromide (GH), with a calibration range of 10–300 μM and a detection limit of 7.33 μM (S/N = 3). Moreover, the biosensor possesses good storage stability, which can achieve the high-throughput screening of AChE inhibitor drugs from traditional Chinese medicines (TCMs). The present work thus demonstrates the promising application of LIG technology in constructing light-addressable PEC sensing devices with high performance and low cost.