Nanogold/Bi2S3 Nanorods Catalyzed Silver Deposition for Carbon Nanohorns-Enhanced Electrochemical Immunosensing of Escherichia coli O157:H7. Issue 9 (1st January 2017)

• Record Type: Journal Article
• Authors: Zhang, Jing; Song, Xinhe; Xiong, Zhanbing; Dong, Haifeng; Wang, Wenchang; Chen, Zhidong
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 9(2017)
• Page Start: H572
• Page End: H578
• Publication Date: 2017-01-01
• Subjects: Bi2S3 nanorods -- Carbon nanohorns -- Electrochemical sensors -- Escherichia coli O157:H7 immunoassay -- Signal amplification -- Silver deposition; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1151706jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : This work designed an ultrasensitive electrochemical immunosensor for Escherichia coli O157:H7 ( E. coli O157:H7) detection using carbon nanohorns as immobilization scaffold and nanogold/Bi2 S3 nanorods (Au/Bi2 S3 NRs) as a signal tag to catalyze silver deposition for signal amplification. Au/Bi2 S3 NRs prepared by in situ growth of nanogold on Bi2 S3 nanorods was used as a tracing tag to label signal antibody, which induced silver deposition for anodicstripping analysis. The immunosensor was constructed by immobilizing capture antibody on carbon nanohorns modified electrode with the aid of polyethylene glycol film. Through a sandwich-type immunoreaction, Au/Bi2 S3 NRs tags were captured on the immunoconjugates to induce a silver deposition process. The electrochemical stripping signal of the deposited silver was used to monitor the immunoreaction. The Au/Bi2 S3 NRs-mediated silver enhancement along with the carbon nanohorns-promoted electron transfer led to high detection sensitivity of E. coli O157:H7 antigen. Under the optimal conditions, the immunosensor exhibited a wide linear dependence on the logarithm of the concentration of E. coli ranging from 40 to 2.0 × 10 6 cfu mL −1 with a detection limit of 6 cfu mL −1 . Moreover, the proposed sensor was successfully applied in the detection of E. coli O157:H7 in real samples indicating its possibility in practical application.