Papers Abstract

Biocompatible silica nanoparticles conjugated with azidocoumarin fortrace level detection and visualization of endogenous H2S in PC3 cells
The silica nanoparticles (SiO2NPs) conjugated with azidocoumarin (Cy-N3) was applied for the selectiveand sensitive H2S detection, even when H2S was present in 1000-fold excess of other bio thiols and ions.In the silica nanoprobes, azide in the Cy-N3group acted as the recognition element, and the probe wasbiocompatible. The nanoprobe displayed blue emission at 456 nm and excitation at 367 nm. After intro-ducing H2S into the probe solution, the fluorescent intensity at 456 nm increased linearly as a functionof H2S concentration (correlation coefficient, 0.9970), and the limit of detection was 6 nM. The enhancedfluorescent emission intensity was due to H2S-mediated reduction of the electron-withdrawing azideinto electron-donating amine. The SiO2NPs@Cy-N3and its reaction products with H2S (SiO2NPs@Cy-NH2) were characterized by1H NMR and TEM. The probe also showed low cytotoxicity and could traceendogenous H2S in physiological pH. We therefore then successfully utilized it to detect H2S in living PC3cells. The probe was also successfully employed for detection of H2S gas using Whatman papers coatedwith SiO2NPs@Cy-N3.