Silver nanoparticles decorated and tetraphenylethene probe doped silica nanoparticles: A colorimetric and fluorometric sensor for sensitive and selective detection and intracellular imaging of hydrogen peroxide.

In this work, we report a novel sensor for colorimetric and fluorometric H2 O2 sensing which is based on silver nanoparticles decorated and tetraphenylethene probe doped silica nanoparticles (Ag@TPE-SiO2 NPs). A positively charged tetraphenylethene (TPE) probe is doped into silica nanoparticles, and the nanoparticles exhibit strong fluorescence emission due to aggregation-induced emission (AIE) of the TPE probe. Ag nanoparticles (AgNPs) are prepared in situ on the surface of the silica nanoparticles. AgNPs serve as a nanoquencher which can quench the AIE emission of the TPE-SiO2 NPs efficiently. However, AgNPs can be oxidized to Ag+ by H2 O2 , which leads to fluorescence recovery and color fading of the Ag@TPE-SiO2 NPs. The dual-readout strategy allows sensitive analysis of H2 O2 . The detection limit of the fluorometric and colorimetric assay is 0.28 and 2.1 μM, respectively. And the nanosensor also shows good selectivity. In addition, analysis of H2 O2 in human serum and intracellular imaging of H2 O2 are both demonstrated. With the good analytical properties of merit, the proposed nanoprobe has a promising potential for H2 O2 related bioanalysis and biomedical applications.