Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an, 710062, PR China.
Analyst. 2009 Jul;134(7):1361-5. doi: 10.1039/b819842j. Epub 2009 Apr 2.
We report herein the development of a highly sensitive and selective colorimetric detection method for cysteine using gold nanoparticles probes. This assay relies upon the distance-dependent optical properties of gold nanoparticles, the self-assembly of cysteine on gold nanoparticles, and the interaction of a 2:1 cysteine/Cu2+ complex. In the presence of Cu2+, cysteine could rapidly induce the aggregation of gold nanoparticles, thereby resulting in red-to-blue (or purple) color change. The concentration of cysteine can be determined by monitoring with the naked eye or a UV-vis spectrometer. The present limit of detection for cysteine is 10 nM. This method exhibits excellent selectivity for cysteine over other alpha-amino acids, glutathione, thioglycolic acid and mercaptoethyl alcohol.
我们在此报告了一种使用金纳米粒子探针的高灵敏度和选择性比色检测半胱氨酸的方法。该测定法依赖于金纳米粒子的距离相关光学性质、半胱氨酸在金纳米粒子上的自组装以及 2:1 半胱氨酸/Cu2+ 络合物的相互作用。在 Cu2+存在下，半胱氨酸可以迅速诱导金纳米粒子的聚集，从而导致颜色从红色变为蓝色（或紫色）。可以通过肉眼或紫外-可见分光光度计监测来确定半胱氨酸的浓度。半胱氨酸的检测限目前为 10 nM。该方法对半胱氨酸具有优异的选择性，超过其他α-氨基酸、谷胱甘肽、巯基乙酸和巯基乙醇。
