Target mediated bioreaction to engineer surface vacancy effect on Bi2O2S nanosheets for photoelectrochemical detection of FEN1.

Photoelectrochemistry represents a promising technique for bioanalysis, though its application for the detection of Flap endonuclease 1 (FEN1) has not been tapped. Herein, this work reports the exploration of creating oxygen vacancies (Ov) in situ onto the surface of Bi 2 O 2 S nanosheets via the attachment of dopamine (DA), which underlies a new anodic PEC sensing strategy for FEN1 detection in label-free, immobilization-free and high-throughput modes. In connection to the target-mediated rolling circle amplification (RCA) reaction for modulating the release of the DA aptamer to capture DA, the detection system showed good performance toward FEN1 analysis with a linear detection range of 0.001–10 U/mL and a detection limit of 1.4 × 10−4 U/mL (S/N = 3). This work features the bioreaction engineered surface vacancy effect of Bi 2 O 2 S nanosheets as a PEC sensing strategy, which allows a simple, easy to perform, sensitive and selective method for the detection of FEN1. This sensing strategy might have wide applications in versatile bioasssays, considering the diversity of a variety of biological reactions may produce the DA aptamer. Synopsis: A PEC sensing platform based on Bi 2 O 2 S nanosheets has been constructed, which utilizes target mediated rolling ring amplification reaction to regulate the release of dopamine. Dopamine binds to the surface of Bi 2 O 2 S in situ to form surface defects and complete signal transduction, thereby realizing the facile and high-throughput detection of target FEN1. [Display omitted] • Dopamine coordination generates oxygen vacancies in situ on the surface of Bi 2 O 2 S nanosheets. • A label-free, immobilization-free, and high-throughput PEC sensing platform for FEN1 detection was developed. • The FEN1 was detected with a low detection limit of 1.42 × 10−4 U/mL. • The first report on the PEC detection of FEN1. • A new perspective was provided to explore Bi 2 O 2 S materials as an efficient PEC signal transducer. [ABSTRACT FROM AUTHOR]