Analytical and Testing Center, Shanxi Normal University, Shanxi, Linfen 041004, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Aug;79(3):418-22. doi: 10.1016/j.saa.2011.02.045. Epub 2011 Mar 30.
The competitive reaction between ethambutol and two fluorescent probes (i.e., berberine and palmatine) for occupancy of the cucurbit[7]uril (CB[7]) cavity was studied by spectrofluorometry. The CB[7] reacts with these probes to form stable complexes, and the fluorescence intensity of the complexes is greatly enhanced. In addition, the excitation and emission wavelengths of their complexes moved to wavelengths of 343 nm and 495 nm, respectively. However, the addition of ethambutol dramatically quenches the fluorescence intensity of the two complexes. Accordingly, a couple of new fluorescence quenching methods for the determination of ethambutol were established. The methods can be applied for quantifying ethambutol. A linear relationship between the fluorescence quenching values (ΔF) and ethambutol concentration exists in the range of 5.0-1000.0 ng mL(-1), with a correlation coefficient (r) of 0.9997. The detection limit is 1.7 ng mL(-1). The fluorescent probe of berberine has higher sensitivity than palmatine. This paper also discusses the mechanism of fluorescence indicator probes.
通过荧光光谱法研究了乙胺丁醇与两种荧光探针（即小檗碱和巴马汀）竞争占据葫芦[7]脲（CB[7]）空腔的反应。CB[7]与这些探针反应形成稳定的配合物，并且配合物的荧光强度大大增强。此外，它们的配合物的激发和发射波长分别移动到 343nm 和 495nm。然而，乙胺丁醇的加入会显著猝灭两个配合物的荧光强度。因此，建立了几种用于测定乙胺丁醇的新荧光猝灭方法。这些方法可用于定量乙胺丁醇。在 5.0-1000.0ng mL(-1)范围内，荧光猝灭值（ΔF）与乙胺丁醇浓度之间存在线性关系，相关系数（r）为 0.9997。检测限为 1.7ng mL(-1)。小檗碱荧光探针比巴马汀具有更高的灵敏度。本文还讨论了荧光指示剂探针的机理。
