A Ratio-Fluorescent Probe Based on Gold Nanoclusters and Carbon Dots for Escherichia Coli Detection

Escherichia coli, as a prevalent foodborne pathogen, can pose a significant threat to human health. Hence, developing the effective methods for Escherichia coli (E. coli) determination is vital. In this work, we constructed a new ratio fluorescent probe for the prompt detection of E.coli based on gold nanoclusters (AuNCs) and blue carbon dots (bCDs). The experimental conditions, including copper concentration incubation temperature and incubation time, were systematically optimized in order to obtain the optimal results. The fluorescence intensity ratio (I630/I450) of AuNCs and bCDs showed a good linear relationship with the concentration of E.coli. The linear concentration range was determined to be 103 - 107 CFU*mL-1, with a low limit of detection (LOD, 120 CFU*mL-1). This approach based on the mechanism of copper cocatalysis presents a sensitive and convenient strategy for the detection of E.coli, and has a promising future in the field of food safety.