Detection of Bacillus Anthracis Using Fluorescence Immunoassay with Quantum Dots Labels

A method for detecting Bacillus anthracis (B. anthracis) was developed using indirect immunofluorescence technique with quantum dots (QDs) as fluorescent probes. B. anthracis could be selectively labeled with QDs, which was demonstrated by fluorescence microscope and F4500 spectrofluorometer. A laboratory-made system including biosensor and device was used as detection apparatus. A linear relationship of the fluorescence intensity and log total count of B. anthracis was obtained with correlation coefficient of 0.9554 from 1 × 102 CFU mL−1 to 1 × 106 CFU mL−1 and a low relative standard deviation (RSD) of 2.19%. By comparing the fluorescence intensity of B. anthracis and other bacillus, this method showed good specificity. Because of simple operation and less detection time (1 h) than traditional methods and quantitative detection, this method has potential prospect in monitoring B. anthracis and other biowarfare agents.