TWO PHOTON INDUCED FLUORESCENCE OF ALKANES, DETERGENTS & MEMBRANES

胆甾烷是一种完全饱和的烷烃， 胆固醇。 我们观察到胆甾烷的荧光发射 当用皮秒激光脉冲激发时，最大值接近235 nm 在298 nm处。 在235 nm处的这种发射被证明是由于双光子 激发 胆甾烷在环戊烷中的荧光寿命 在1.4ns附近。 胆甾烷是有效的碰撞 用甲醇和氧气淬灭。 这些结果表明 胆甾烷或其类似物可用作内源性探针， 生物膜 双光子激发避免了真空的使用 紫外线波长（130-170 nm），这需要特殊的光学器件， 排除氧气。 这一观察可能会导致更普遍的 使用烷烃荧光作为细胞膜的探针。

Cholestane is a fully saturated alkane with a structure analogous to cholesterol. We observed fluorescence emission from cholestane with a maximum near 235 nm when excited with picosecond laser pulses at 298 nm. This emission at 235 nm was shown to be due to two-photon excitation. The fluorescence lifetime of cholestane in cyclopentane was found to be near 1.4 ns. Cholestane is efficiently collisionaly quenched by methanol and oxygen. These results suggest that cholestane or its analogs can be used as intrinsic probes in biological membranes. Two-photon excitation avoids the use of vacuum ultraviolet wavelength (130-170 nm), which require special optics and exclusion of oxygen. This observation may lead to the more general use of alkane fluorescence as a probe of cell membranes.