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Yan H, Wu L, Wang J, Zheng Y, Zhao F, Bai Q, Hu H, Liang H, Niu X. Target-triggered dual signal amplification based on HCR-enhanced nanozyme activity for the sensitive visual detection of Escherichia coli. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:496-502. [PMID: 38078483 DOI: 10.1039/d3ay01824e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
The detection of foodborne pathogens is crucial for food hygiene regulation and disease diagnosis. Colorimetry has become one of the main analytical methods in studying foodborne pathogens due to its advantages of visualization, low cost, simple operation, and no complex instrument. However, the low sensitivity limits its applications in early identification and on-site detection for trace analytes. In order to overcome such a limitation, herein we propose a joint strategy featuring dual signal amplification based on the hybridization chain reaction (HCR) and DNA-enhanced peroxidase-like activity of gold nanoparticles (AuNPs) for the sensitive visual detection of Escherichia coli. Target bacteria bound specifically to the aptamer domain in the capture hairpin probe, exposing the trigger domain for HCR and forming the extended double-stranded DNA (dsDNA) structures. The peroxidase-like catalytic capacity of AuNPs can be enhanced significantly by dsDNAs with the sticky ends of dsDNAs being adsorbed on AuNPs and the rigidity of dsDNAs causing the spatial regulation of AuNP concentration. The intensity of the enhancement was linearly related to the number of target bacteria. With the above strategy, the detection limit of our colorimetric method for Escherichia coli was down to 28 CFU mL-1 within a short analytical time (50 min). This study provides a new perspective for the sensitive and visual detection of early bacterial contamination in foods.
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Affiliation(s)
- Hangli Yan
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Linghao Wu
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Jingyu Wang
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Yi Zheng
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Fengxia Zhao
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Qinqin Bai
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Hongmei Hu
- Hengyang Center for Disease Control and Prevention, Hengyang 421001, China
| | - Hao Liang
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Xiangheng Niu
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
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