Near-infrared fluorescent probe for selective detection of Cu in living cells and in Vivo.

A NIR-rhodamine fluorescent probe was designed and successfully synthesized. The structure of the probe NRh-Cu was characterized by 1H NMR, 13C NMR and HRMS. The probe was found to show high sensitivity and high selectivity. The detection limit was calculated to be as low as 0.95 ppb. The sensing mechanism was proposed and confirmed by HRMS spectra. Furthermore, it could be used for imaging Cu2+ in living cells and in vivo.