Facile fabrication of visible light photoelectrochemical immunosensor for SCCA detection based on BiOBr/Bi2S3 heterostructures via self-sacrificial synthesis method

Publication date: 1 June 2019

Source: Talanta, Volume 198

Author(s): Dawei Fan, Chunzhu Bao, Xin Liu, Jinhui Feng, Dan Wu, Hongmin Ma, Huan Wang, Qin Wei, Bin Du

Abstract

A novel visible light photoelectrochemical immunosensor based on BiOBr/Bi₂S₃ heterostructures was fabricated to detect squamous cell carcinoma antigen (SCCA). Bi₂S₃ nanoparticles formed on the BiOBr microflowers by the self-sacrificial synthesis method based on the facile reaction between BiOBr and S^2- ions. The BiOBr/Bi₂S₃ composites exhibited excellent visible light photoelectrochemical activity, when ascorbic acid (AA) was employed as a perfect electron donor. The photocurrent intensity of BiOBr/Bi₂S₃ modified ITO electrode arrived at around 20 µA, which was approximately 30 times than that of pure BiOBr. Dopamine formed easily polydopamine film via self-polymerization on the surface of BiOBr/Bi₂S₃ composites to immobilize SCCA antibody. Under the optimal condition, this photoelectrochemical immunosensor realized the ultrasensitive determination of SCCA. With the logarithm of SCCA concentration in the range of 0.001–75 ng mL⁻¹, the specific binding between SCCA and antibody led to the linearly decrease of photocurrent signal with a low detection limit of 0.3 pg mL⁻¹ (S/N = 3). This facilely constructed photoelectrochemical immunosensor maybe have promising practical application in photocatalysis, analytical detection and biosensor, etc.

Graphical abstract

from A via a.sfakia on Inoreader http://bit.ly/2TOFH9A