Boosting the Electrochemical Performance of PI-5-CA/C-SWCNT Nanohybrid for Sensitive Detection of E. coli O157:H7 From the Real Sample

Huan Wang; Yanmiao Fan; Qiaoli Yang; Xiaoyu Sun; Hao Liu; Wei Chen; Ayesha Aziz; Shenqi Wang

doi:10.3389/fchem.2022.843859

Boosting the Electrochemical Performance of PI-5-CA/C-SWCNT Nanohybrid for Sensitive Detection of E. coli O157:H7 From the Real Sample

Front Chem. 2022 Feb 10:10:843859. doi: 10.3389/fchem.2022.843859. eCollection 2022.

Authors

Huan Wang¹, Yanmiao Fan², Qiaoli Yang¹, Xiaoyu Sun¹, Hao Liu¹, Wei Chen¹, Ayesha Aziz¹, Shenqi Wang¹

Affiliations

¹ Advanced Biomaterials and Tissue Engineering Center, College of Life Science and Technology, Huazhong University of Life Science and Technology, Wuhan, China.
² School of Chemical Science and Engineering Fiber and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden.

Abstract

Redox activity is an important indicator for evaluating electrochemical biosensors. In this work, we have successfully polymerized indole-5-carboxylic acid into poly-5-carboxyindole nanomaterials (PI-5-CA), using its superior redox activity, and introduced carboxylated single-walled carbon nanotubes (C-SWCNTs) to synthesize a composite material. Finally, a synthesized composite material was used for the modification of the glass carbon electrode to fabricate the PI-5-CA/C-SWCNTs/GCE-based immunosensor and was successfully applied for the sensitive detection of E. coli O157:H7. The fabricated immunosensor exhibited an outstanding electrocatalytic activity toward the detection of E. coli O157:H7 with a remarkably lowest limit of detection (2.5 CFU/ml, LOD = 3 SD/k, n = 3) and has a wide linear range from 2.98×10¹ to 2.98×10⁷ CFU/ml. Inspired from the excellent results, the fabricated electrode was applied for the detection of bacteria from real samples (water samples) with a good recovery rate (98.13-107.69%) as well as an excellent stability and specificity. Owing to its simple preparation, excellent performance, and detection time within 30 min, our proposed immunosensor will open a new horizon in different fields for the sensitive detection of bacteria from real samples.

Keywords: E. coli O157:H7; carboxylated single-walled carbon nanotubes; electrochemical immunosensor; indole-5-carboxylic acid; plate counting method; poly-5-carboxyindole.