Design and Function of Fluorescent Silica Nanoparticles for Bacteria Detection

Food safety is one of the concerned issues. As a result, the managements to protect consumers adequately from foodborne illness are to be required. The standard method for specific pathogen detection is culture method. However, conventional methods based on culture have disadvantages of time-consuming, which might cause infectious diseases to spread rapidly. Therefore, rapid and simple methods for bacteria detection have been attracting much attention in this research area. Recently, we developed dipicolylamine (dpa)-modified fluorescent silica nanoparticles (FSiNP) for bacteria detection. In this study, we prepared two FSiNPs (Bt/dpa-HCC/FSiNP and B/FSiNP) whose surfaces were modified with dipicolylamine or phenyl boronic acid. Cu-Bt/dpa-HCC/FSiNP formed aggregates with both S. aureus and E. coli, whereas B/FSiNP formed aggregates with S. aureus selectively. Bt/dpa-HCC/FSiNP could examine the existence of bacteria in water and B/FSiNP could detect either S. aureus or E. coli. These results demonstrated that surface-functionalized silica nanoparticles could detect bacteria in water