Highly selective, naked-eye and fluorescent “off-on” probe for detection of histidine/histidine-rich proteins and its application in living cell imaging

A highly selective colorimetric and fluorescence enhanced probe S1 (M2@Cu) for histidine and histidine-rich proteins has been developed. In neutral aqueous ethanol solution, probe S1 can selectively detect histidine out of twenty DNA encoded amino acids by showing a color change from brownish red to light green, and with a fluorescence enhancement up to 99-fold at 537 nm, simultaneously.