Fluorophore-quencher complexes (Cu/Al) of coumarin Schiff bases as chemosensors for the detection of L-glutamic acid and L-arginine: and studies.

This study reports the development of new probes RR1 ((1)-1-(1-(6-bromo-2-oxo-2-chromen-3-yl)ethylidene)ethyl thiosemicarbazone) and RR2 ((1)-1-(1-(6-bromo-2-oxo-2-chromen-3-yl)ethylidene)phenyl thiosemicarbazone), which selectively showed fluorescence turn 'OFF' response towards Cu and Al. Further, complexes of RR1-Cu2+ and RR2-Al3+ acted as chemosensors for the detection of L-amino acids. RR1-Cu2+ selectively detected L-arginine (fluorescence turn 'ON'), and RR2-Al3+ selectively detected L-glutamic acid (fluorescence turn 'ON'). The existence of the fluorophore-quencher complexes RR1-Cu2+ and RR2-Al3+ was confirmed by theoretical studies. Further, the chemosensors RR1-Cu2+ and RR2-Al3+ have three possible structural isomers ( - A, B and C) and ( - D, E and F), as confirmed by theoretical studies. bio-imaging of the probes (RR1 and RR2), complexes (RR1-Cu2+ and RR2-Al3+) and complexes associated with L-arginine () and L-glutamic acid () was performed in the MDA-MB-231 cell line using their IC concentrations. In addition, live cell imaging studies were conducted using as the model organism.