Carbon quantum dots (CQDs) are a nanoscale luminescent material composed of carbon elements, with excellent optical properties, low toxicity, biocompatibility, water solubility and chemical stability. CQDs can be combined with biomolecules (such as DNA, antibodies, enzymes, etc.) to form fluorescent biosensors used to detect various bioanalytical targets, such as bacteria, viruses, proteins, nucleic acids, etc.

The application of carbon quantum dot fluorescent biosensors in E. coli detection refers to the use of carbon quantum dot fluorescent biosensors to achieve rapid, sensitive and specific detection of E. coli in food or water. Escherichia coli is a common foodborne pathogenic bacteria, which can cause diarrhea, abdominal pain, fever and other symptoms, and even lead to hemolUS syndrome and sepsis in severe cases. Therefore, the timely and effective detection of Escherichia coli is of great significance for ensuring food safety and human health.

Based on the application of carbon quantum dot fluorescent biosensor in Escherichia coli detection:

The recent potential of carbon quantum dots in emerging technologies and nanosecurity, including biosensing, drug delivery, energy and bioimaging. A fluorescent biosensor based on carbon quantum dots and single-stranded DNA (ssDNA) that enables the detection of E. coli O157: H7 is mentioned. The sensor utilizes electrostatic interactions between carbon QDs and ssDNA to reduce the fluorescence intensity. When added to the target E. coli, the ssDNA binds to the antigen on its surface, thus releasing carbon QDs to restore the fluorescence intensity. E. coli O157: H7 can be quantitatively detected by measuring changes in fluorescence intensity.

Electrochemical biosensing interface of carbon quantum dots-Fe3O4 nanomaterials (CQDs-Fe3O4), used for the detection of Escherichia coli O157: H7. The sensing interface utilizes CQDs-Fe3O4 as a carrier for the probe DNA and is immobilized on a glass carbon electrode by electrochemical reduction. When added to the target E. coli, the probe DNA binds to the antigen on its surface, thereby changing the resistance and capacitance of the electrode surface. Quantitative detection of E. coli O157: H7 can be achieved by measuring the changes in the electrochemical impedance spectrum (EIS) signal.

Reference Documentation:

[1]Fluorescent carbon dots are the new quantum dots: an overview of their potential in emerging technologies and nanosafety.

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