Photo induced chemical modification of surface ligands for aggregation and luminescence modulation of copper nanoclusters in the presence of oxygen.

Surface modification of nanoparticles has been a popular approach to tailor the properties of nanoparticles. Herein we report the unprecedented photo oxidation of cysteine moeties on the surface of copper nanoclusters (Cu NCs) leading to aggregation of Cu NCs, which further led to quenching of luminescence of the latter. Upon illumination of a dispersion of Cu NCs at 365 nm wavelength light, the luminescence of Cu NCs was completely quenched.