L-Histidine Stabilized Copper Nanoclusters as a Fluorescence Probe for Determination of Fluazinam

In this contribution, a one-pot synthesis method possessing the advantages of simple, green and low-cost had been researched for the preparation of L-histidine-stabilized Cu nanoclusters (Cu NCs). Subsequently, the structure and optical properties of as-prepared Cu NCs were studied by using Fourier transform infrared (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy and UV-Vis absorption spectroscopy. TEM image of the Cu NCs showed high dispersion with an average diameter of 2.0 nm. Fluorescence spectrum displayed that the Cu NCs emitted green fluorescence (emission wavelength of 492 nm) under excitation wavelength of 393 nm. Moreover, the as-synthesized Cu NCs illustrated excellent performances, such as good water solubility, UV stability and high-salt resistance. Interestingly, the fluorescence intensity of as-prepared Cu NCs was obviously quenched in the presence of fluazinam. Under optimal conditions, the relative fluorescence intensity was linear with the fluazinam concentrations from 1 to 40 μ M, with a detection limit of 0.25 μ M. Eventually, the fluorescence sensor was successfully used to determine fluazinam in real water samples.