Lighting of a rhodamine-based fluorescent lamp using ClO4- as a connector: detection by the naked eye and cell imaging studies of trace amounts of ClO4- ions

A visible light excitable (lambda(ex) = 520 nm), rhodamine-based, perchlorate selective 'turn on' fluorescent probe, RHENTU, is prepared and characterized by spectroscopic techniques. The probe is suitable for use in the detection of ClO4- by the naked eye. It is also capable of detecting ClO4- in contaminated living cells under a fluorescence microscope. Common anions viz. F-2, Cl-2, Br-2, I-2, N-, NCO2, NO-, NO32, SCN2, CN2, CH3COO-, SO42- and H2PO4- do not interfere with these processes. The binding constant of RHENTU for ClO4 2 has been determined to be 2.9 x 10(3) M-1/2 using the Benesi-Hildebrand equation. Addition of ClO42 to RHENTU afforded an intense red emission with a quantum yield (4.5 x 10(-2)) five times greater than that of free RHENTU. The lowest detection limit (LOD) of RHENTU for ClO4- is 1 x 10(-7) M.