CONCENTRATION DEPENDENT FLUORESCENCE SPECTROSCOPY OF ACRIDINE ORANGE

突变体的双光子激发截面(？(2))测量 绿色荧光蛋白(EGFP)已经在 810-980 nm的波长范围，使用82 MHz的~80ps激光脉冲 重复率。在每个波长，与功率相关的测量 的订单(例如PH11为2.02 Q 0.02)进行了确认 导致观测到的荧光的非线性过程。这个 ？(2)对缓冲液的pH值(4.9、5.8、8和11)的依赖关系为 也进行了调查。？(2)=97q5×10-50cm4.s/光子。 PH11在950 nm处测量。在PH5中，该值降低了约76% 缓冲区。以~950 nm为中心的宽带表明， S_2&lt；-S_0跃迁为~21053厘米~(-1)，似乎与 缓冲液的pH值。弱肩在~840 nm处的强度 随pH值的降低而略有增加。两个版本之间的比较 单、双光子激发截面及其启示 对所涉及的光谱进行了绘制。

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.