[Research on rapid detection technology of airborne pathogenic organisms based on up-conversion phosphor technology]

Objective: To explore the application of up-conversing phosphor technology (UPT) to detect pathogenic organisms in the air. Methods: The performance of UPT was verified with Staphylococcus aureus, Yersinia pestis and Escherichia coli O157 as simulated strains, including stability, specificity, sensitivity and response time tests; Air particle sampler is used to collect air samples in the field microenvironment test chamber, and UPT is used for detection. At the same time, compared with the traditional culture method, the practicability of UPT is verified. Results: The coefficient of variation in laboratory was 9.62% and 8.02% when the concentration of 10⁷ CFU/ml and 10⁸ CFU/ml were detected by UPT. The results were less than the allowable target, and the detection system had good stability. The specificity of UPT was verified by Staphylococcus aureus. The results showed that no non-Staphylococcus aureus was detected, and the positive detection rate of different kinds of Staphylococcus aureus was 100%. The specificity of the detection system was good. The sensitivity of UPT for detecting Staphylococcus aureus was 10⁴ CFU/ml. Detection sensitivity of Yersinia pestis ≥10³ CFU/ml; The detection sensitivity of Escherichia coli O157 is ≥10³ CFU/ml, and the response time of UPT to bacteria is within 15 min (all 10 min 15 s). The detection results of bacteria contentration in the air of the on-site microenvironment test cabin by UPT showed that when the concentration of Escherichia coli O157 in the air reached above 10⁴ CFU/m³, the detection results of UPT were positive, and with the increase of air concentration, the numerical concentration measured by UPT showed an upward trend, which was positively correlated with the concentration of bacteria in the air. Conclusion: UPT may be feasible as a rapid method to evaluate the species and contentration of pathogenic organisms in the air.