Affiliation:
1. School of Medicine, Hunan Normal University, Changsha, China
2. School of Public Health, Jilin University, Changchun, China
3. Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
4. Engineering Research Center of Reproduction and Translational Medicine of Hunan Province, Changsha, China
Abstract
ABSTRACT
It is critical to develop quick, accurate, and efficient sterilization for detecting
Escherichia coli
O157:H7 in order to prevent infections and outbreaks of foodborne illnesses. Herein, we established a colorimetric biosensor with sterilizing properties using copper selenide nanoparticles to detect
E. coli
O157:H7. The sample was mixed with magnetic nanoprobes and nanozyme probes to form a sandwich structure, and then the unbound nanozyme probes were collected by magnetic separation. Finally, the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate)-hydrogen peroxide (H
2
O
2
) reporting system was added for signal amplification. The change from colorless to green can be seen with the naked eye. Under the optimal conditions, the detection range of
E. coli
O157:H7 was 10
2
–10
6
CFU/mL, and the detection limit was 0.35 × 10
2
CFU/mL. The total detection time was 80 minutes, which can be successfully applied to milk and mineral water. In addition, the colorimetric sensor can kill the target bacteria by irradiating it under a 980-nm laser for 5 minutes. In conclusion, this sensor is a promising tool for rapidly detecting foodborne pathogens and promptly eliminating bacteria.
IMPORTANCE
Escherichia coli
O157:H7 is a major threat to public health. At present, the detection methods for
E. coli
O157:H7 mainly include traditional bacterial culture, immunology (enzyme-linked immune-sorbent assay) and molecular biology techniques (polymerase chain reaction). These methods have the limitations of professional operation, waste of time and energy, and high cost. Therefore, we have developed a simple, fast, bactericidal colorimetric biosensor to detect
E. coli.
O157:H7. The entire process was completed in 80 minutes. The method has been successfully applied to milk and mineral water samples with satisfactory results, proving that the method is an effective method for real-time detection and inactivation of bacteria.
Funder
MOST | National Natural Science Foundation of China
Publisher
American Society for Microbiology