Aneurine hydrochloride protected fluorescent copper nanoclusters: preparation and application in the specific detection of Fe3+ in microbial samples

Abstract:

[Objective] To prepare the fluorescent stable aneurine hydrochloride (VB₁)-protected copper nanoclusters with VB₁ as a protective ligand and reducing agent for the detection of trace amounts of Fe³⁺. [Methods] We used VB₁ as a protective ligand and reducing agent to synthesize VB₁-protected copper nanoclusters. Then, we characterized the copper nanoclusters by UV visible absorption spectrum, fluorescence spectrum, and particle size, and explored their pH responsiveness, selectivity to Fe³⁺, and linear range in the detection of Fe³⁺. [Results] The prepared VB₁-protected copper nanoclusters had good water solubility, excellent stability, and ultrafine size. As the fluorescent probes to detect Fe³⁺, the copper nanoclusters showed good linearity in the ranges of 0–5 μmol/L and 5–500 μmol/L, with the limit of detection of 0.085 μmol/L. When being used to detect Fe³⁺ in the actual microbial sample of Trichophyton, the copper nanoclusters showed the recovery rate between 95.67% and 107.94%. [Conclusion] We used VB₁ as a protective ligand and reducing agent to prepare fluorescent stable VB₁-protected copper nanoclusters. On the basis of the selective quenching of Fe³⁺ by the copper nanoclusters, we established a simple, rapid, and sensitive method for the detection of Fe³⁺ and successfully applied it to the detection of Fe³⁺ in Trichophyton. This method has a good application prospect in actual microbial samples.