Synthesis of novel organic-inorganic hybrid fluorescent microspheres and their applications as Fe(III), Hg(II) and biothiols probes

Organic-inorganic hybrid fluorescent microspheres (OI-FMs) without typical fluorophores were prepared. Fluorescence quantum yield of OI-FMs is up to 70.0% after being heated in an oven at 120 °C (named as OI-FMs-120). Interestingly, OI-FMs-120 shows different detection performances in different solvents. It can be used for qualitative and quantitative detection of Fe3 + with a detection limit of 37.8 nM in absolute ethanol. While in aqueous solution, it can be applied as an ON-OFF-ON fluorescent probe. Fluorescence of the probe is quenched by Hg2 + and later recovered by biothiols. The detection limit is as low as 34.9 nM for Hg2 +, 91.0 nM for Cys, 0.12 μM for Hcy and 0.13 μM for GSH in aqueous medium, respectively.