m-Dinitrobenzene directed aggregation-induced emission enhancement of cysteine modified fluorescent copper nanoclusters

Abstract

Abstract The sensing ability of l -cysteine modified fluorescent copper nanoclusters (Cys-CuNCs) was investigated in details with various nitro-aromatics. In addition to the reported sensing analyte i.e. picric acid (PA) that quenched the fluorescence of Cys-CuNCs, the presence of m-dinitrobenzene (m-DNB) dramatically enhanced the fluorescence of Cys-CuNCs in aqueous medium (PBS buffer, pH\u202f=\u202f9.0) among the other tested nitro-aromatics. The aggregation-induced emission enhancement of Cys-CuNCs in the presence of m-DNB was supported with DLS analysis. Under optimum conditions, this developed Cys-CuNCs exhibits a linear response in the concentrations range of 1.30\u202f×\u202f10−6\u202fM–9.90\u202f×\u202f10−8\u202fM with the limit of detection down to 1.3\u202f×\u202f10−7\u202fM for m-DNB.