Luminescent AIZS-GO nanocomposites as fluorescent probe for detecting copper(II) ion

A selective copper(II) sensor based on graphene oxide (GO) modified Ag-In-Zn-S (AIZS) quantum dots (QDs) was proposed. The fluorescence of the water-soluble AIZS QDs was quenched after addition of Cu2+ ion, which was triggered by the aggregation of the QDs in the form of R-COO-(Cu2+)-OOC-R, as verified by the TEM and FTIR. The fluorescence probe can be applied to detect Cu2+ ion in a wide concentration range of 0-850 μM based on the degree of fluorescence quenching, with its limitation of detection (LOD) and R2 of 0.18 μM and 0.99, respectively. Moreover, the nanosensor can distinguish Cu2+ ion from other ions, offering great potentials in copper(II) determination in drinking water.