Fluorescent probe for Cu(2+) and the secondary application of the resultant complex to detect cysteine

A special fluorescent probe has been developed, one that demonstrated excellent “off-on-type” change in fluorescence with high selectivity toward Cu(2+). Interestingly, the probe–Cu(2+) complex could detect cysteine due to the ability of this amino acid to strongly coordinate Cu(2+), and no obvious interference was observed from other amino acids and anions. According to the proposed mechanism, addition of cysteine induced decomplexation of the probe–Cu(2+) form. Furthermore, the results of confocal microscopy experiments demonstrated the potential of using the probe to image Cu(2+) in living cells and mice.