Sensitized room temperature phosphorescence of biacetyl in AOT reversed micelles-dodecylammonium α-naphthylacetate as energy donor

The energy transfer between dodecylammonium α-naphthylacetate (DA+NAA−) and biacetyl has been investigated in normal micelles of CTAC, SDS and reversed micelles of AOT. A surfactant with α-naphthylacetate counterion has been synthesized. Parameters that may influence the sensitized phosphorescence of biacetyl, including the concentration of AOT, solubilized water, and the concentration of DA+NAA− and biacetyl, have been examined. The absorption and luminescence spectra as well as polarization data are used to elucidate the factors that may affect the sensitized phosphorescence of biacetyl. It is suggested that the sensitized phosphorescence of biacetyl be affected by two factors, the protective effect afforded by micellar media and the Poisson distribution. Since the α-naphthylacetate moiety is associated with the DA+ surfactant, it is anchored to the head group in reversed micelles of AOT where biacetyl is solubilized. It has been observed that the RTP characterization of biacetyl sensitized by DA+NAA− with changing of AOT or W([H2O][AOT]) in AOT reversed micelles is different from that sensitized by NAA. The remarkable influence of water content on the sensitized phosphorescence of biacetyl has been observed with the increase of water content. The detection limit of biacetyl by using DA+NAA− as the donor is about three times lower than that by using NAA as the donor. It indicates that DA + NAA− is a more efficient donor than NAA.