Copper clusters-based luminescence assay for tetracycline and cellular imaging studies

Two copper nanoclusters (NCs) stabilized by L-cysteine and glutathione have been reported. The nanoparticles with ultrafine size had excellent water solubility and exhibited green or red emission respectively. Particularly, the two copper clusters were found to be responsive to the presence of tetracycline (TC) and on-off quenching effects were achieved. After incubation, the cell staining and target-detection features could be still effective in two adherent live cells. The nanocluster showed very low cytotoxicity and excellent biological compatibility. Accordingly, the special photophysical properties of copper NCs will be attractive for various potential applications such as bio-sensing and medical diagnosis.