Multicolor fluorescence regulation of N doped silicon quantum dots and the multiple applications

Abstract

Currently-reported silicon quantum dots (SiQDs) usually have blue fluorescence, which limits its applications in biological fields, so it is of great significance to develop SiQDs with non-blue fluorescence, especially adjustable multicolor fluorescence. In this study, neutral red was selected as the dopant to prepare a series of N doped silicon quantum dots (N-SiQDs) with adjustable fluorescence colors from blue to orange by simply controlling preparation conditions. Due to the complexion between the N-SiQDs and Cu2+, the fluorescence of N-SiQDs was quenched, and thus N-SiQDs were employed as the fluorescent probe for the detection of Cu2+ in tap water and artificial cerebrospinal fluid with good selectivity, wide linear range (0.05–5 μM) and low detection limit (0.02 μM). In addition, the N-SiQDs were applicable to cell imaging and intracellular detection of Cu2+ as the orange fluorescence of the N-SiQDs could avoid background fluorescence interference from biological samples. Furthermore, N-SiQDs of varied fluorescence colors could be well solidified, exhibiting the potential for the optical device. The present study provided an easy-to-handle and effective way to synthesize multicolor fluorescent SiQDs.