Phase-modulation fluorometer using an ultraviolet light-emitting diode
Phase-modulation fluorometer using an ultraviolet light-emitting diode
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DOI：
10.1007/s10043-000-0495-x
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发表时间：
2000-11-01
期刊：
影响因子：
1.2
通讯作者：
Araki, T
中科院分区：
文献类型：
--
作者：
Iwata, T;Kamada, T;Araki, T
我们已经构建了一个相位调制荧光计使用市售的紫外发光二极管（UV LED）作为激发光源。紫外LED的中心波长为370 nm，光谱带宽为10 nm。将10 mA（pp）调制电流叠加在5 mA的偏置电流上，固定频率在1-20 MHz范围内。样品上的平均UV功率为250 μ W。通过光电倍增管检测荧光信号，并将其输入多功能数字示波器。使用数字示波器的操作功能直接读出从扩散板获得的荧光信号和参考信号之间的相位差。为了证明系统的性能，测量了25 ppm罗丹明6 G在乙醇中的荧光寿命和10 ppm硫酸奎宁在0.1 N H（2）SO（4）中的荧光寿命。计算出的寿命分别为5.8 ns和19.1 us，与文献报道的一致。紫外发光二极管和数字示波器的组合使得荧光计简单，易于构建，成本低。
We have constructed a phase-modulation fluorometer using a commercially-available ultraviolet light-emitting diode (UV LED) as an excitation light source. The center wavelength of the UV LED is 370 nm and its spectral bandwidth is 10 nm. A 10 mA(pp) modulation-current was superimposed on a bias current of 5 mA with a fixed frequency in the range of 1-20 MHz. The average UV power on the sample was 250 muW. The fluorescence signal was detected by a photomultiplier tube and was fed into a versatile digital oscilloscope. The phase difference between the fluorescence signal and the reference signal obtained from a diffusion plate was directly read out using the operational functions of the digital oscilloscope. To demonstrate the system performance, fluorescence lifetimes of 25 ppm rhodamine 6G in ethanol and of 10 ppm quinine sulfate in 0.1 N H(2)SO(4) were measured. The calculated lifetimes of 5.8 ns and 19.1 us, respectively, agreed with those reported in the literature. The combination of the UV LED and the digital oscilloscope made the fluorometer simple and easy to construct with low cost.