A hemicyanine-based “turn-on” fluorescent probe for the selective detection of Cu²⁺ ions and imaging in living cells

A novel hemicyanine-based fluorescent probe was developed for the fast, selective, and reversible detection of Cu²⁺ ions with "turn-on" fluorescence response in the aqueous solution. The sensing mode was demonstrated through fluorescence, UV-vis, HRMS, ¹H NMR, and DFT calculations. The probe was successfully used for the imaging of Cu²⁺ ions in living cells.