Synthesis, photophysical properties and application of dye doped water soluble silica-based nanoparticles to label bacteria E. coli O157:H7

Minh Tan Pham, Thi Van Nguyen, Thuy Duong Vu Thi, Ha Lien Nghiem Thi, Kim Thuan Tong, Thanh Thuy Tran, Viet Ha Chu, Jean-Claude Brochon and Hong Nhung Tran

Abstract

Organically modified silicate (ORMOSIL) nanoparticles (NPs) doped with rhodamine 6G and rhodamine B (RB) dyes were synthesized by Stöber method from methyltriethoxysilane CH₃Si(OCH₃)₃ precursor (MTEOS). The NPs are surface functionalized by cationic amino groups. The optical characterization of dye-doped ORMOSIL NPs was studied in comparison with that of free dye in solution. The synthesized NPs were used for labeling bacteria E. coli O157:H7. The number of bacteria have been counted using the fluorescent spectra and microscope images of labeled bacteria. The results show the ability of NPs to work as biomarkers