Hamamatsu Photonics K. K., Joko-cho, Hamamatsu 431-3196, Japan.
Phys Chem Chem Phys. 2009 Nov 14;11(42):9850-60. doi: 10.1039/b912178a. Epub 2009 Sep 17.
We reevaluate the absolute fluorescence and phosphorescence quantum yields of standard solutions by using a novel instrument developed for measuring the absolute emission quantum yields of solutions. The instrument consists of an integrating sphere equipped with a monochromatized Xe arc lamp as the light source and a multichannel spectrometer. By using a back-thinned CCD (BT-CCD) as the detector, the sensitivity for spectral detection in both the short and long wavelength regions is greatly improved compared with that of an optical detection system that uses a conventional photodetector. Using this instrument, we reevaluate the absolute fluorescence quantum yields (Phi(f)) of some commonly used fluorescence standard solutions by taking into account the effect of reabsorption/reemission. The value of Phi(f) for 5 x 10(-3) M quinine bisulfate in 1 N H(2)SO(4) is measured to be 0.52, which is in good agreement with the value (0.508) obtained by Melhuish by using a modified Vavilov method. In contrast, the value of Phi(f) for 1.0 x 10(-5) M quinine bisulfate in 1 N H(2)SO(4), which is one of the most commonly used standards in quantum yield measurements based on the relative method, is measured to be 0.60. This value is significantly larger than Melhuish's value (0.546), which was estimated by extrapolating the value of Phi(f) for 5 x 10(-3) M quinine bisulfate solution to infinite dilution using the self-quenching constant. The fluorescence quantum yield of 9,10-diphenylanthracene in cyclohexane is measured to be 0.97. This system can also be used to determine the phosphorescence quantum yields (Phi(p)) of metal complexes that emit phosphorescence in the near-infrared region: the values of Phi(p) for Ru(bpy)(3) (bpy = 2,2'-bipyridine) are estimated to be 0.063 in water and 0.095 in acetonitrile under deaerated conditions at 298 K, while that in aerated water, which is frequently used as a luminescent reference in biological studies, is reevaluated to be 0.040.
我们使用一种新型仪器重新评估了标准溶液的绝对荧光和磷光量子产率，该仪器用于测量溶液的绝对发射量子产率。该仪器由一个积分球组成，配备有单色化的 Xe 弧光灯作为光源和多通道光谱仪。通过使用背照式 CCD（BT-CCD）作为探测器，与使用传统光电探测器的光学检测系统相比，在短波长和长波长区域的光谱检测灵敏度大大提高。使用该仪器，我们考虑到再吸收/再发射的影响，重新评估了一些常用荧光标准溶液的绝对荧光量子产率（Phi(f)）。在 1N H(2)SO(4)中，5 x 10(-3) M 硫酸奎宁的 Phi(f)值测量为 0.52，与 Melhuish 使用改进的 Vavilov 方法获得的 0.508 值非常吻合。相比之下，在 1N H(2)SO(4)中，1.0 x 10(-5) M 硫酸奎宁的 Phi(f)值测量为 0.60，这是相对方法中量子产率测量最常用的标准之一，该值明显大于 Melhuish 估计的 0.546 值，该值是通过使用自猝灭常数将 5 x 10(-3) M 硫酸奎宁溶液的 Phi(f)值外推到无限稀释来估计的。在环己烷中，9,10-二苯基蒽的荧光量子产率测量为 0.97。该系统还可用于测定发射近红外磷光的金属配合物的磷光量子产率（Phi(p)）：在 298 K 下，Ru(bpy)(3)（bpy = 2,2'-联吡啶）在水中的 Phi(p)值估计为 0.063，在乙腈中的 Phi(p)值估计为 0.095，在脱氧条件下，而在充氧水中，该值经常被用作生物研究中的发光参考，被重新评估为 0.040。
