Highly sensitive detection of Shigella flexneri using fluorescent silica nanoparticles.

Robust signal amplification tactic is a good solution for improving detection sensitivity. Unprocessed fluorophores have many limitations. Here we describe an effective strategy for highly sensitive detection of bacteria by using fluorescent conjugated nanoparticles. The nanoparticles were synthesized using silica as matrix. Fluorescein isothiocyanate distributed in the matrix. S. flexneri specific antibody was coated on the surface of the nanoparticles. Compared to the traditional fluorescent antibody, these antibody-coated fluorescent conjugated nanoparticles were resistant to photobleaching and could ensure prolonged microscope checking for a small number of target bacteria. These nanoparticles could be used in routine bacterial detection for different species.