Simple Light-Triggered Fluorescent Labeling of Silica Nanoparticles for Cellular Imaging Applications.

A simple and mild light-triggered fluorescent labeling approach, based on the photolysis and reactive carbene insertion of diazirine, to rapidly generate fluorescent nanoparticles is reported. Proof of concept studies demonstrated that the non-fluorescent SiNPs could be covalently labeled by diazirine-conjugated fluorescein (dFITC) upon photo irradiation (λ=365 nm) to afford fluorescent SiNPs with good fluorescent stability and low cytotoxicity. In vitro cellular imaging results indicated that the internalization of SiNPs into living cells could be readily visualized based on fluorescein-labeled SiNPs (F-SiNPs) in real time. We believe that the light-triggered labeling approach may offer a valuable method for surface modification of nanomaterials to achieve new functions.