CdS quantum dots/Au nanoparticles/ZnO nanowire array for self-powered photoelectrochemical detection of Escherichia coli O157:H7

• Published in: Biosensors & bioelectronics 2020-02, Vol.149, p.111843-111843, Article 111843
• Main Authors: Dong, Xiuxiu, Shi, Zengliang, Xu, Chunxiang, Yang, Chi, Chen, Feng, Lei, Milan, Wang, Junjie, Cui, Qiannan
• Format: Article
• Language: English
• Subjects: Aptasensor; E. coli O157:H7; Photoelectrochemical; Self-powered
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2019.111843

In this paper, the hydrothermally grown ZnO nanowire array (NWs) was modified by Au nanoparticles (NPs) and CdS quantum dots (QDs) to construct a high-performance photoelectrochemical (PEC) electrode. The aligned ZnO NWs, which decorated Au NPs and CdS QDs have the effective light absorption range from UV to visible region. This hybrid structure provided a self-powered PEC electrode with a favorable energy-band configuration for fast charge separation and transportation. Meanwhile, the Au NPs and CdS QDs also made increase of the surface area to improve the immobilization of the analytes. After assembling aptamer as recognition element, this composite nanoarray was further developed as a self-powered PEC biosensor by synergizing above multiple enhancement factors. The PEC aptasensor exhibited a rapid response in a wide linear range of 10–107 CFU/mL with the detection limit as low as 1.125 CFU/mL to Escherichia coli O157:H7 (E. coli O157:H7). This approach would offer an alternative PEC transduction for fast environment monitoring and clinical diagnosis related to pathogenic bacteria. •A photoelectrochemical (PEC) platform was developed based on ZnO nanowire array decorated Au NPs and CdS QDs.•CdS QDs@ E. coli O157:H7 aptamer is in-situ synthesized.•The perfect design of PEC electrode has effective light absorption range from UV to visible region.•The LOD was as low as 1.125 CFU/mL for E. coli O157:H7.