Synthesis of fluorescent ionic liquid-functionalized silicon nanoparticles with tunable amphiphilicity and selective determination of Hg²⁺

Abstract

Fluorescent silicon nanoparticles have attracted much attention in recent years due to their superior optical properties, strong photostability, low toxicity, and favorable biocompatibility. In this paper, we have prepared imidazolium ionic liquid-functionalized silicon nanoparticles (IL@SiNPs) via a simple one-pot hydrothermal route from 1-(trimethoxysilyl)propyl-3-methylimidazolium chloride that was denoted as [SmIm]Cl and sodium citrate. The synthetic IL@SiNPs could be a novel label-free sensing probe for sensitive and selective detection of Hg²⁺ ions with energy transfer from IL@SiNPs to Hg²⁺. A good linear relationship was obtained from 0 to 40 μmol L^-1 with a detection limit of 0.45 μM. Furthermore, the solubility of the IL@SiNPs can be facilely converted by anion exchange without complex chemical modification. The ionic liquid-modified SiNPs may show great promise in biological and environmental applications due to their excellent biocompatibility and optical performance.