SENSITIZED LANTHANIDE LUMINESCENCE IN AOT REVERSED MICELLES - PURINE COMPOUNDS AS ENERGY DONOR

Sensitized lanthanide luminescence by purine compounds in AOT reversed micelles has been studied. A significant enhancement of sensitized ro om temperature luminescence has been observed using lanthanide Tb3+ as energy acceptor in AOT reversed micelles at low AOT concentration and W value, and weak Tb3+ emission has been observed in CTAB reversed mi celles. The results indicate that Tb3+ ions are strongly bound to the sulfonate group of the AOT surfactant. Parameters including the concen tration of AOT, solubilized water as well as acceptor concentration th at may influence the sensitized lanthanide luminescence have been exam ined. The characteristics of luminescence and lifetimes of Tb3+ were u sed to elucidate the factors that affected sensitized luminescence. Th e results shaw that Tb3+ emission is quenched by the high frequency OH vibrations of the surrounding water molecules, the loss of Tb3+ emiss ion in high AOT concentration and W value suggests that the Tb3+ catio n retains water in its coordination sites. The quenching process is st atic quenching. The low AOT concentration and W value should be reconm mended for obtaining high sensitivity in analytical application. The d etection limits for purine and its deriviations are between 8.0 x 10(- 9)similar to 8.0 x 10(-7) mol.dm(-3).