Electrochemical Biosensing Interface Based on Carbon Dots-Fe3O4 Nanomaterial for the Determination of Escherichia coli O157:H7.

Xiaofeng Lin,Ying Kuang,Yanqiu Mei,Xiaoming Ma,Qitong Huang,Min Yang,Chen He,Yan Luo,Huifang Zhang

doi:10.3389/fchem.2021.769648

Xiaofeng Lin, Ying Kuang + Show 7 more

Open Access

https://doi.org/10.3389/fchem.2021.769648

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Abstract

Escherichia coli (E. coli) O157:H7 can cause many food safety incidents, which seriously affect human health and economic development. Therefore, the sensitive, accurate, and rapid determination of E. coli O157:H7 is of great significance for preventing the outbreak and spread of foodborne diseases. In this study, a carbon dots-Fe3O4 nanomaterial (CDs-Fe3O4)-based sensitive electrochemical biosensor for E. coli O157:H7 detection was developed. The CDs have good electrical conductivity, and the surface of carbon dots contains abundant carboxyl groups, which can be used to immobilize probe DNA. Meanwhile, the CDs can be used as a reducing agent to prepare CDs-Fe3O4 nanomaterial. The Fe3O4 nanomaterial can improve the performance of the electrochemical biosensor; it also can realize the recovery of CDs-Fe3O4 due to its magnetism. As expected, the electrochemical biosensor has excellent specificity of E. coli O157:H7 among other bacteria. The electrochemical biosensor also exhibited good performance for detecting E. coli O157:H7 with the detection range of 10–108 CFU/ml, and the detection limit of this electrochemical biosensor was 6.88 CFU/ml (3S/N). Furthermore, this electrochemical biosensor was successfully used for monitoring E. coli O157:H7 in milk and water samples, indicating that this electrochemical biosensor has good application prospect. More importantly, this research can provide a new idea for the detection of other bacteria and viruses.

Highlights

In recent years, food poisoning caused by foodborne pathogens has frequently occurred worldwide, which is the most prominent public health problem in the world (Hou et al, 2020; Duan et al, 2021)
Some bioanalytical methods have been applied for E. coli O157: H7 detection, including enzyme-linked immunosorbent assay (ELISA) (Guo et al, 2016; Zhao et al, 2020), lateral flow immunochromatographic detection technology (Xie et al, 2014; Ye et al, 2020), polymerase chain reaction (PCR) (Dong et al, 2015), and so on
The above morphology characterization can indicate that carbon dots (CDs)-Fe3O4 nanomaterial has been successfully prepared

Summary

Introduction

Food poisoning caused by foodborne pathogens has frequently occurred worldwide, which is the most prominent public health problem in the world (Hou et al, 2020; Duan et al, 2021). A CDs-Fe3O4 nanomaterial-based electrochemical biosensor is constructed for detecting E. coli O157:H7, which is highly sensitive and reliable (Figure 1). This electrochemical biosensor can achieve a good linear and detection limit for monitoring E. coli O157:H7.

Results

Conclusion