A novel rosamine-based fluorescent probe for the rapid and selective detection of cysteine in BSA, water, milk, cabbage, radish, apple, and pear.

A novel fluorescent probe (RA), based on the rosamine skeleton bearing acrylate group, has been reasonably designed and prepared, which employed an addition-cyclization-elimination sequence reaction mechanism to detect cysteine. RA displayed rapid response to cysteine within 1.5 min, and exhibited satisfactory selectivity for cysteine over H2S, glutathione (Glu), and homocysteine (Hcy), due to the formation of seven-membered lactam favored kinetically. Fluorescence ratio was utilized to detect cysteine from 6.0 to 20.0 μM with a detection limit of 0.29 μM. More, RA was used to monitor cysteine in BSA, water, milk, milk powder, cabbage, radish, apple, and pear.