College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, PR China.
Anal Chim Acta. 2010 Feb 5;659(1-2):238-42. doi: 10.1016/j.aca.2009.11.057. Epub 2009 Dec 2.
A simple, rapid, and sensitive determination of total free thiol groups in biological samples using cerium (IV) as a fluorescence probe is reported. The protocol is based on the oxidation of thiols by Ce(IV) and the formation the Ce(III) disulfide complex, which gives a fluorescence enhancement of Ce(III) at 352 nm. Using glutathione (GSH) and cysteine as model compounds, incubation with Ce(IV) at 25 degrees C for 6 min results in fluorescence, whose intensity is proportional to the thiol concentration in the range of 1.00-160 nM. The detection limits for GSH and cysteine are 0.05 and 0.08 nM, respectively. Other common metal ions and amino acids have little interference to the thiol detection. Cu(II) was used as a fluorescence quencher to eliminate potential interference from tryptophan. The method has been successfully applied to assays of free thiol contents in pig liver tissue samples, with a RSD lower than 2.5% and recovery between 100.6% and 102.3%.
本文报道了一种使用铈（IV）作为荧光探针测定生物样品中总游离巯基的简单、快速、灵敏的方法。该方案基于 Ce(IV)对巯基的氧化和 Ce(III)二硫化物配合物的形成，该配合物在 352nm 处使 Ce(III)的荧光增强。使用谷胱甘肽（GSH）和半胱氨酸作为模型化合物，在 25°C 下与 Ce(IV)孵育 6 分钟会产生荧光，其强度与巯基浓度在 1.00-160nM 的范围内成正比。GSH 和半胱氨酸的检测限分别为 0.05 和 0.08 nM。其他常见的金属离子和氨基酸对巯基检测几乎没有干扰。Cu(II) 被用作荧光猝灭剂，以消除色氨酸可能的干扰。该方法已成功应用于猪肝组织样品中游离巯基含量的测定，其相对标准偏差（RSD）低于 2.5%，回收率在 100.6%至 102.3%之间。
