Detection And Inactivation Of Pathogenic Bacteria Based On Glow-type Chemiluminescence Sensor

Foodborne bacterial infection seriously threatens human health.It is of great significance to build a multifunctional platform for pathogen point-of-care testing（POCT）and elimination.However,most of the developed strategies either focus on the sensitive detection of pathogenic bacteria without function of subsequent bacterial inactivation or focus on the high-efficiency inactivation without function of early warning.POCT is an effective method for rapid detection of bacteria outside the laboratory,and chemiluminescence（CL）has broad prospects in in-situ POCT because its free of excitation light source and high sensitivity.However,the short CL time is not conducive to the repeatability and stability.Therefore,the development of long-time and high-intensity CL system is the focus of research in recent years.In this study,a pathogenic bacteria detection and inactivation platform was designed and constructed from mercaptophenylboronic acid（MPBA）with bacterial recognition function and copper selenide(Cu Se _NPs)with peroxidase-like and photothermal property(Cu Se _NPs@MPBA).First,we found that functionalization of the MPBA on the surface of Cu Se _NPs could impart slow diffusion effect at the catalytic interface,which significantly prolonged the CL duration and switched from flash-type to glow-type.Second,MPBA can bind to peptidoglycan on the bacterial cell wall and form Cu Se _NPs@MPBA/bacterial complex,the complex is separated from the system via simple centrifugation,resulting in obvious decrease of CL intensity owing to the reduction of the catalyst in the supernatant.Finally,Cu Se _NPs also has superiority of photothermal properties.The attached Cu Se _NPs@MPBA can cause temperature increment of Cu Se _NPs@MPBA/bacteria under NIR irradiation.Thus,temperature can also serve as readout signal for bacterial detection with thermal camera as detector.At the same time,the pathogenic bacteria can be simultaneously inactivated via the photothermal treatment of Cu Se _NPs@MPBA,which is beneficial to prevent secondary contamination and transmission.Therefore,this multifunctional nanoplatform can act as a visual sensor and bactericide for S.aureus and E.coli,the use of smartphone makes the detection more simple,portable and reliable.With CL as the output signal,the limits of detection（LOD）for S.aureus and E.coli are 1.25 CFU m L^-1 and 1.01 CFU m L^-1,respectively.Satisfactory detection limit can also be obtained by using temperature as output signal.The bactericidal rate was 99.2%against S.aureus and 99.8%against E.coli,respectively.It is easy to operate,inexpensive,and has great potential in food safety,environmental monitoring and clinical applications.