An Ultrasensitive Photoelectrochemical Biosensor based on AgBiS2/CdS Photoanode and Multiple Signal Amplification Strategy for the Detection of Dibutyl Phthalate Plasticizer

Herein, a novel AgBiS2/CdS heterojunction was developed for the construction of sensitive biosensor for dibutyl phthalate (DBP) detection. Compared with the pristine CdS, the AgBiS2/CdS heterojunction exhibited enhanced photocurrent because of the promoted photo-carriers transfer due to the matched energy band arrangement between AgBiS2 and CdS. Based on this AgBiS2/CdS photoanode and a signal amplification strategy integrates DNAzyme-assisted walker reaction and hybridization chain reaction, a sensitive PEC sensing platform was designed for the detection of DBP. A wide detection ranges from 1 fM to 10 nM and a low detection limit of 0.3 fM were achieved. The proposed PEC biosensor with satisfactory sensitivity, selectivity, and stability shows potential application in environmental monitoring.