Construction of a New Probe Based on Copper Chaperone Protein for Detecting Cu in Cells.

Biomacromolecular probes have been extensively employed in the detection of metal ions for their prominent biocompatibility, water solubility, high selectivity, and easy modification of fluorescent groups. In this study, a fluorescent probe FP was constructed. The probe FP exhibited high specificity recognition for Cu. With the combination of Cu, the probe was subjected to fluorescence quenching. The research suggested that the probe FP carried out the highly sensitive detection of Cu with detection limits of 1.7 nM. The fluorescence quenching of fluorescamine was induced by Cu perhaps due to the PET (photoinduced electron transfer) mechanism. The FP-Cu complex shows weak fluorescence, which is likely due to the PET quenching effect from Cu to fluorescamine fluorophore. Moreover, the probe FP can be employed for imaging Cu in living cells. The new fluorescent probe developed in this study shows the advantages of good biocompatibility and low cytotoxicity. It can be adopted for the targeted detection of Cu in cells, and it has promising applications in the mechanism research and diagnosis of Cu-associated diseases.