上海科技大学知识管理系统

["With the rise of bacterial infections and antibiotic resistance, spectroscopic devices originally developed for bacterial detection have shown promise to rapidly identify bacterial strains and determine the ratio of live to dead bacteria. However, the detection of the photoreactivated pathogens remains a critical concern. This study utilizes fluorescence and Raman spectroscopy to analyze bacterial responses to UV irradiation and subsequent photoreactivation. Our experimental results reveal limitations in fluorescence spectroscopy for detecting photoreactivated bacteria, as the intense fluorescence of tryptophan and tyrosine amino acids masks the fluorescence emitted by thymine molecules. Conversely, Raman spectroscopy proves more effective, showing a detectable decrease in band intensities of E. coli bacteria at 1248 and 1665 cm-1 after exposure to UVC radiation. Subsequent UVA irradiation results in the partial restoration of these band intensities, indicating DNA repair and bacterial photoreactivation. This enhanced understanding aims to improve the accuracy and effectiveness of these spectroscopic tools in clinical and environmental settings.","This study investigates the effectiveness of fluorescence and Raman spectroscopy in detecting bacterial photoreactivation. Fluorescence spectroscopy shows limitations, because the intense fluorescence of tryptophan and tyrosine masks fluorescence emitted by thymine molecules. In contrast, Raman spectroscopy proves more effective in identifying photoreactivated bacteria. Our experimental results indicate that specific Raman band intensities of E. coli decrease due to bacterial inactivation after UVC exposure. These intensities partially recover with subsequent UVA irradiation, demonstrating DNA repair and bacterial photoreactivation. These findings aim to enhance the accuracy of spectroscopic methods in clinical and environmental applications, addressing the critical concern of detecting photoreactivated pathogens.image"]