Determination of Fe(III) ion and cellular bioimaging based on a novel photoluminescent silicon nanoparticles

The determination approaches of Fe (III) in biological samples were developed by a novel water-soluble silicon nanoparticles (SiNPs). The SiNPs were synthesized by a facile microwave-assisted method, and simultaneously featured strong blue fluorescence (photoluminescence quantum yield: 25.2%), long lifetime (similar to 13.29 ns) and good photo-stability. The fluorescence intensities of SiNPs were gradually quenched with Fe (III) concentration increasing from 2.0 to 50 mu mol/L. The detection limit of the established method was 0.56 mu mol/L and the precision for eleven replicate detections of 20 mu mol/L Fe (III) was 3.2% (relative standard deviation, RSD). The spiked recoveries were 99.0%-104.5%. Results of the lifetime decay and cyclic voltammetry (CV) evidenced that the electron transfer was responsible for the fluorescence quenching mechanism of SiNPs and Fe (III). Moreover, the SiNPs were successfully applied in the determination of Fe(III) in different environmental waters and human serum. Finally, the resulting SiNPs exhibited the green fluorescence in HeLa cells as the optical probe.

Automated summary

A novel method for determining Fe(III) in biological samples was developed using water-soluble silicon nanoparticles (SiNPs) with strong fluorescence properties. The mechanism involved electron transfer and showed low detection limits and high precision, making it suitable for applications in various environmental waters and human serum.