ONE & TWO PHOTON INDUCED FLUORESCENCE OF NADH

我们研究了nadh的稳态和时间分辨发射。 NAMH是由单光子和双光子激发产生的。类似 观察到了两种激发模式的发射光谱。这个 对于双光子激发，NADH的基本各向异性接近0.54 从690到740 nm，比0.37的值高46% 观察到的是单光子激发。两者之间的细微差别 观察到了单光子和双光子NADH的多指数衰变。 激发，但目前可用的分辨率不允许我们 结论是衰变是不同的。NADH-LADH-IBA络合物的形成 使NADH荧光的平均寿命延长一个数量级 由单光子和双光子激发产生。分子内 与NADH的腺嘌呤部分的相互作用是导致 在激发波长观测到的NADH荧光的退偏振 OPE小于300 nm，TPE小于600 nm。NADH显示 双光子激发的一个小截面表明 来自NADH的荧光将较难观察到 双光子荧光显微镜，可能不会干扰 用于标记细胞的其他外源性探针的TPIF观察。

We examined the steady-state and time-resolved emission of NADH and NAMH resulting from one-photon and two-photon excitation. Similar emission spectra were observed for both modes of excitation. The fundamental anisotropy of NADH is near 0.54 for two-photon excitation from 690 to 740 nm, which is 46% higher than the value of 0.37 observed for one-photon excitation. Minor differences in the multi-exponential decays of NADH were observed for one- and two-photon excitation, but presently available resolution does not allow us to conclude the decays are distinct. NADH-LADH-IBA complex formation led to an order of magnitude larger average lifetimes of NADH fluorescence resulting from one- and two-photon excitation. Intramolecular interactions with adenine part of NADH are responsible for the depolarization of NADH fluorescence observed for excitation wavelength below 300 nm for OPE and 600 nm for TPE, respectively. NADH displays a low cross-section for two-photon excitation which suggests that fluorescence from NADH will be moderately difficult to observe with two-photon fluorescence microscopy, and may not interfere with observations of TPIF of other extrinsic probes used to label cells.