Dual-mode visible light-induced aptasensing platforms for bleomycin detection based on CdS-In2S3 heterojunction

CdS-In2S3 heterojunction with enhanced photoelectrochemical (PEC) performance was synthesized to construct dual-mode visible light-induced biosensors for highly sensitive and selective detection of bleomycin (BLM). Due to improved absorption in the visible region and suppressed recombination of electron-hole pairs in the heterojunction, CdS-In2S3 composite exhibited enhanced photocurrent response under visible light illumination. Using CdS-In2S3 as photoactive materials and BLM-binding aptamer as recognition element, a PEC aptasensor displaying a declined photocurrent response to BLM was facilely constructed, which was linear to BLM concentration in the range of 5.0-250 nM. On the other hand, the CdS-In(2)S(3 )photoanode was employed to construct a photofuel cell (PFC). In such a PFC, the oxidation of water on CdS-In2S3 photoanode under visible light illumination and the reduction of oxygen on Pt cathode led to the generation of electricity. When BLM-binding aptamer was immobilized on CdS-In2S3 photoanode, the output power of the PFC was inversely proportional to the logarithm of BLM concentration from 10 to 250 nM, offering a visible light-induced self-powered sensing platform for BLM detection. Both of the proposed sensors showed high selectivity, good reproducibility and high stability. They were successfully applied to the determination of BLM in human serum samples.