Manganese-Doped Zinc-Mediated Assembly of Gold Nanoclusters as a Dual-Emitting Fluorescent Probe for Surface-Controlled Ratiometric Detection of Biothiols in Complex Biofluids.

We developed a ratiometric fluorescent probe using zinc-mediated assemblies of Mn2+-doped gold nanoclusters for the sensitive detection of biologically relevant thiols. Thiol binding selectively enhanced the nanoclusters's emission at 477 nm, while Mn2+ emission at 570 nm remained unaltered, enabling precise ratiometric sensing. The probe showed performance in complex media, like blood serum, and showed high selectivity, with no allied response to non-thiol analogues. This platform offers a reliable and practical tool for thiol detection under physiological conditions.