CONCENTRATION DEPENDENT FLUORESCENCE SPECTROSCOPY OF ACRIDINE ORANGE

双光子激发截面（？(2))突变体测定 绿色荧光蛋白（EGFP）在大肠杆菌中的表达 波长范围810-980 nm，使用82 MHz的~80 fs激光脉冲 重复率 在每个波长，功率相关测量 进行了确认的顺序（例如，2.02 q 0.02的pH 11）的 非线性过程，导致观察到的荧光。 的 依赖？(2)对缓冲液的pH值（4.9、5.8、8和11）进行了测定。 也调查了。 ? (2)= 97 q 5 x 10-50 cm4.s/光子。 在950 nm处测量pH 11。 在pH 5时，该值降低约76 缓冲液 以~950 nm为中心的宽带表明， S2<-S 0跃迁为~ 21053 cm-1，似乎与 缓冲液的pH值。 ~840 nm处弱肩的强度 随着pH值的降低而略有增加。 比较 单光子和双光子激发激发截面和见解 所涉及到的光谱学。

Two-photon excitation cross-section (?(2)) measurements of mutant Green Fluorescent Protein (EGFP) has been carried out in the wavelength range of 810-980 nm using ~80 fs laser pulses at 82 MHz repetition rate. At each wavelength, power-dependent measurements were conducted to confirm the order (e.g. 2.02 q 0.02 for pH11) of the nonlinear process that leads to the observed fluorescence. The dependence of ?(2) on pH-value (4.9, 5.8, 8, and 11) of the buffer was also investigated. ?(2) = 97 q 5 x 10-50 cm4.s/photon.molecule was measured at 950 nm for pH11. This value was reduced by ~76% in pH5 buffer. A broad band centered at ~950 nm suggests that the energy of S2<---- S0 transition is ~ 21053 cm-1 and seems to be independent of the pH of the buffer. The intensity of a weak shoulder at ~840 nm slightly increases as the pH-value decreases. Comparison between the one- and two-photon excitation excitation cross-section and insights on the involved spectroscopy are drawn.