Detection And Inactivation Of Pathogenic Bacteria Based On Biological Orthogonal Makers

Nowadays,bacterial infection can cause many high-risk diseases that perplex human beings and pose a serious threat to global public health.So far,the rapid and effective detection and treatment of bacterial infection in vivo have certain limitations.At the same time,after the completion of pathogen detection,it will multiply on the surface of the detection sensor,causing secondary pollution and affecting the sensitivity of the sensor.Therefore,it is of great significance to develop a rapid and sensitive integrated platform for detection and sterilization.In this study,a new AIE molecule MTPE-FCy P with near-infrared fluorescence and high active oxygen generation capacity was synthesized.Then,the amphiphilic molecule DSPE-PEG₂₀₀₀-DBCO was used to coat MTPE-FCy P by nano precipitation method to prepare hydrophobic AIE molecules into highly biocompatible nanoparticles（MTFP NPs）.Based on the fluorescence characteristics of MTFP NPs,an integrated platform for the detection and inactivation of foodborne pathogens was constructed,and further confirmed its application in real-time tracking of pathogenic bacteria infection and enhanced PDT.During the preparation of MTFP NPs,with the increase of the number of DSPE-PEG₂₀₀₀-DBCO,the size of MTFP NPs increased,and the fluorescence and ROS generation capacity of MTFP NPs also increased.The DBCO group on the surface of MTFP NPs can react with the N₃group metabolically labeled on the bacterial cell wall,showing a stronger targeting ability.Using the fluorescence signal of MTFP NPs,MRSA and KREC were selected as the model bacteria of Gram-positive bacteria and Gram-negative bacteria respectively for detection.The detection range was 10²-10⁶CFU/m L.MTFP NPs have good ROS generation ability under white light irradiation,and realize in-situ inactivation while detecting bacteria.The antibacterial efficiency is as high as 100%to prevent secondary pollution.At the same time,in order to expand the application of MTFP NPs,the in vivo application ability of MTFP NPs was further explored.The fluorescence of MTFP NPs was used to monitor the fluorescence in vivo in real time.After 4 hours of tail vein injection,it could target around the wound.Mice treated with D-Azala and MTFP NPs showed stronger and more lasting fluorescence signals in infected skin.At the same time,through photodynamic therapy,the number of bacteria in infected tissues can be significantly reduced,which can effectively promote the wound healing of mice infected with bacteria.Therefore,the study proved the advantages of biorthogonal labeling of MTFP NPs in the accurate detection and treatment of bacteria.