Facile synthesis of CuS nanosheets probe for resonance light scattering and visual detecting l-cysteine

A highly efficient resonance light scattering (RLS) and visual probe based on mercaptosuccinic acid (MA) modified copper sulfide (CuS) nanosheets has been successfully established for sensitive and selective detection of l -cysteine ( l -Cys). The CuS nanosheets are facilely synthesized via a reductive solution route with MA as reductant and modifier at room temperature. The as-prepared CuS nanosheets have been characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), UV–vis spectra and Fourier transform infrared spectroscopy (FTIR), respectively. Experimental results indicated that formation of hydrogen bonds and thiol-Cu chemical bonds between CuS nanosheets and l -Cys significantly contributed to the sensitivity and selectivity of the proposed method no matter for RLS or visual detection of l -Cys. Under the optimum experimental conditions, the linear range of the l -Cys RLS probe was 2.78 (10σ/K)-7000   nmol/L ( r   =   0.9944), and the detection limit was 0.83   nmol/L (3σ/K). As to visual detection, the detection limit could also be extended to 75   μmol/L.