Preparation and use of tyrosine-capped copper nanoclusters as fluorescent probe to determine rutin

For the first time, we developed a facile, green and low-cost strategy to prepare blue-green emitting fluorescence copper nanoclusters (Cu NCs) by using tyrosine as a protecting agent and hydrazine hydrate as a reducing agent. The tyrosine-protected Cu NCs (Tyr-Cu NCs) were analyzed through fluorescence spectroscopy, UV–vis absorption spectroscopy, fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The as-prepared Cu NCs was well dispersed and possessed good water solubility, excellent photostability and resistance to sodium chloride. The fluorescence intensity of Tyr-Cu NCs (around 480 nm under the excitation wavelength of 435 nm) was obviously quenched in the presence of rutin. According to this characteristic, a selective and sensitive fluorescence analytical method for the determination of rutin was established. The analytical method had a good linear relationship between F 0 /F and the concentrations of rutin (range from 0.1–60 μM) and the detection limit (LOD) was 0.016 μM. The possible mechanism of fluorescence quenching was caused by the IFE and static quenching. Meaningfully, the fluorescent probe was successfully employed to detect rutin in bovine serum samples.