Photocathodic immunosensors generally exhibit fortified anti-interference abilities than photoanodic ones against the detection in biological specimens. Yet, the weak photocurrent signals of the photocathodes have limited evidently the detection performance. Herein, an efficient and feasible photoelectrochemical (PEC) immunosensor was developed on the basis of the featured photocathode-photoanode operating system. In the proposal, the elaborated PEC immunosensor integrated photocathode with photoanode, and the immune recognition occurred just on the photocathode. To illustrate the performance, α-fetoprotein (AFP) was selected as a target antigen (Ag) for detection. TiO2 nanoparticles were decorated with AgInS2 quantum dots (AIS QDs) to fabricate the TiO2/AIS photoanode, and the carbon nanotubes (CNTs) were modified with CuInS2 nanoflowers (CIS NFs) to prepare the CNT/CIS photocathode for the capture AFP antibody (Ab) anchoring. Target Ag detection depended on significant decrease of the photocurrent signal produced by large steric hindrance of the captured AFP molecules. Coupling excellent photoelectric property with anti-interference ability in this elegant PEC immunosensor, sensitive and specific probing of target Ag was realized. The proposed photocathode-photoanode integrating strategy provides a promising way to explore other high-performance PEC immunosensors against the detection in biological matrixes.
Keywords: AFP; Immunosensor; Photoanode; Photocathode; Photoelectrochemistry.
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