The fluorescence enhancement effect of the Tb-Gd-guanosine-5′-triphosphate-phen system and its analytical application

It has been found that Tb3+ can react with guanosine-5'-triphosphate (GTP) and o-phenanthroline (phen), resulting in the intrinsic fluorescence of Tb3+ This fluorescence can be enhanced by adding La Gd3+, LU3+, SC3+, y(3+), and so on, among which Gd3+ produces the greatest enhancement. These are new columinescence systems. The experiments indicate under optimum conditions, the fluorescence intensity of the Tb-Gd-GTP-phen system is proportional to the concentration of GTP over the range 1x10(-9) to 3x10(-5) mol/1. The detection limit is 3.1x10(-10) mol/1. The proposed method provides the most sensitive fluorimetry of GTP so far. The mechanism of the Tb-Gd-GTP-phen system has also been studied. The data indicates that there is a large congeries of Tb-Gd-GTP-phen, and the fluorescence enhancement of the Tb-Gd-GTP-phen system is considered to originate from intramolecular and intermocular energy transfers, and the energy-insulating sheath of the Gd complex.