College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
Analyst. 2012 Aug 21;137(16):3794-9. doi: 10.1039/c2an35734h. Epub 2012 Jul 5.
In this paper, we report a simple, sensitive and selective colorimetric visualization of dopamine (DA) using dithiobis(succinimidylpropionate) (DSP)-modified gold nanoparticles (AuNPs) as probes and ferric ions as cross-linkers. Via the standard amine coupling reaction between the amino groups of DA and activated carboxyl groups of DSP, DA molecules can be assembled onto the surface of DSP-AuNPs. Accordingly, Fe(3+) ions induce a change of DSP-AuNPs in color and UV-vis absorbance by coordinating to the catechol groups of the anchored DA. The pH dependence and mechanism of this method are discussed. A detection limit of 2 nM was obtained, which is lower than those achievable with currently used chromatographic and electrochemical techniques. The feasibility for the detection of DA in artificial cerebrospinal fluid has been demonstrated.
在本文中，我们报告了一种使用二硫代双（琥珀酰亚胺基丙酸酯）（DSP）修饰的金纳米粒子（AuNPs）作为探针，以铁离子作为交联剂，对多巴胺（DA）进行简单、灵敏和选择性比色可视化的方法。通过 DA 的氨基与 DSP 中活化的羧基之间的标准胺偶联反应，DA 分子可以组装到 DSP-AuNPs 的表面。因此，Fe(3+)离子通过与锚定的 DA 的儿茶酚基团配位，诱导 DSP-AuNPs 的颜色和紫外可见吸收发生变化。讨论了该方法的 pH 依赖性和机制。获得了 2 nM 的检测限，低于目前使用的色谱和电化学技术所能达到的检测限。已经证明了该方法在人工脑脊液中检测 DA 的可行性。
