ORGN 669 |
| The application of conjugated polyelectrolytes (CPEs) in developing sensors and biosensors has been studied extensively, due to the extraordinarily efficient quenching of the luminescence emission from CPEs by small molecule electron and energy acceptors. Several effects have been proposed to account for the observed superquenching behavior, for which a “sphere-of-action” model is widely applied to analyze the Stern-Volmer plot data. In this contribution, we show that the aggregation of a CPE (PPECO2-185) induced by the presence of Ca2+ affects greatly the quenching behavior of small molecule quenchers in methanol. With increased concentrations of Ca2+, increased factions of PPECO2-185 aggregate. Simultaneously, in the Stern-Volmer plot, the initial slow-rising period (“induction period”) corresponding to low quencher concentrations is compressed. The results imply that aggregation and/or other conformational changes of CPEs induced by added small molecule quenchers shares important contribution to the overall quenching efficiency. |
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High-Energy Species
1:00 PM-4:40 PM, Thursday, 30 March 2006 Georgia World Congress Center -- C303, Oral
Division of Organic Chemistry |