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

Abstract

In this work, we report a novel sensor for colorimetric and fluorometric H₂O₂ 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 H₂O₂, which leads to fluorescence recovery and color fading of the Ag@TPE-SiO₂ NPs. The dual-readout strategy allows sensitive analysis of H₂O₂. 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 H₂O₂ in human serum and intracellular imaging of H₂O₂ are both demonstrated. With the good analytical properties of merit, the proposed nanoprobe has a promising potential for H₂O₂ related bioanalysis and biomedical applications.

Keywords: Aggregation-induced emission; Colorimetry; H(2)O(2) detection; Intracellular imaging; Tetraphenylethene; Turn-on fluorescence.