One-Step Green Preparation of N-Doped Silicon Quantum Dots for the on-off Fluorescent Determination of Hydrogen Peroxide

Abstract

By using (3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane) and o-phenylenediamine as the reaction substrate, N-doped silicon quantum dots (N-SiQDs) with high quantum yield and excellent optical properties were synthesized by a one-step, simple, low-cost, and green method. Sequentially a N-SiQDs/silver nanoparticles (N-SiQDs/Ag NPs) nanocomplex was constructed as a nanoprobe to develop an “on-off” fluorescent sensing platform for hydrogen peroxide (H2O2). The produced N-SiQDs was characterized by various methods such as transmission electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Due to the surface plasmon-enhanced energy transfer from donor N-SiQDs to acceptor Ag NPs, the fluorescence of N-SiQDs is quenched (“off”) by Ag NPs. In the presence of hydrogen peroxide, it etches the Ag NPs to release N-SiQDs and further increases the fluorescence intensity from N-SiQDs (“on”). Based on this principle, an “on-off” fluorescent sensing platform for hydrogen peroxide was successfully developed. Under the optimized experimental conditions, the results show that the developed sensing platform has a low detection limit (1.5 μM) and wide linear range (5.0 to 200.0 µM) for the determination of hydrogen peroxide.