Photoelectrochemical aptasensor for the detection of 17β-estradiol based on In2S3 and CdS co-sensitized cerium doped TiO2
In this work, a photoelectrochemical (PEC) aptasensor for the detection of 17β-estradiol (E2) based on an In2S3 and CdS co-sensitized cerium (Ce) doped TiO2 (Ce:TiO2) electrode was constructed successfully. In2S3 with advantages of narrow band gap, attractive photoelectric conversion efficiency, and its own superiorities such as hypotoxicity and low pollution could work as one promising material in PEC sensing detection field. Here, a PEC aptasensor making use of In2S3 was fabricated for the detection of E2. Besides, Ce doped into TiO2 introduced a new intrinsic energy band into TiO2, which created an easier electron transfer path. In2S3 and CdS co-loaded on Ce:TiO2 not only improved the photocurrent response but also expanded light absorption range. Meanwhile, an aptamer with specific sequence, served as a recognition unit, was used to specifically bind with E2 to enable detection. Under optimal conditions, the as-prepared aptasensor exhibited linearity range of 10-5-100 ng/mL with detection limit of 4.0 fg/mL. The aptasensor also showed satisfied selectivity, stability and acceptable reproducibility.