Department of Chemistry, East China Normal University, Shanghai 200062, PR China.
J Phys Chem B. 2012 Sep 13;116(36):11180-6. doi: 10.1021/jp302792u. Epub 2012 Sep 4.
In this paper, an electrochemical acetylcholinesterase (AChE) inhibition assay based on three-dimensional ordered macroporous (3DOM) composite was conducted. The 3DOM composite was first fabricated on the glassy carbon electrode by electropolymerization of aniline in the presence of ionic liquid (IL) on a sacrificial silica nanospheres template. After the silica nanospheres were etched, an IL-doped polyaniline (IL-PANI) film with 3DOM morphology was formed. Then, gold nanoparticles (AuNPs) were decorated on the IL-PANI film by electrodeposition. The immobilized AChE on the 3DOM composite displayed favorable affinity to substrate acetylthiocholine chloride (ATCh), and the 3DOM composite showed excellent electrocatalytic effect on thiocholine, the hydrolysis product of ATCh. The presence of IL and AuNPs could improve the sensitivity by accelerating the electron transfer. The designed AChE biosensor was successfully applied to evaluate the AChE inhibition induced by endogenous neurotoxin 1(R),2N-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [(R)-NMSal]. The results demonstrate that (R)-NMSal exerts a considerable effect on AChE activity, and the inhibition is reversible. The developed method offers a new approach for AChE inhibition assay, which is of great benefit in understanding the mechanism behind neurotoxin-induced neurodegenerative disorders.
本文构建了一种基于三维有序大孔（3DOM）复合结构的电化学乙酰胆碱酯酶（AChE）抑制测定法。首先，在牺牲模板二氧化硅纳米球存在的情况下，通过电聚合苯胺在玻碳电极上制备 3DOM 复合结构。然后，刻蚀二氧化硅纳米球后，形成具有 3DOM 形态的离子液体掺杂聚苯胺（IL-PANI）薄膜。接着，通过电沉积将金纳米颗粒（AuNPs）修饰到 IL-PANI 薄膜上。固定在 3DOM 复合结构上的 AChE 对底物产乙酰硫代胆碱（ATCh）具有良好的亲和力，并且 3DOM 复合结构对 ATCh 的水解产物硫代胆碱表现出优异的电催化作用。IL 和 AuNPs 的存在可以通过加速电子转移来提高灵敏度。所设计的 AChE 生物传感器成功地用于评估内源性神经毒素 1(R),2N-二甲基-6,7-二羟基-1,2,3,4-四氢异喹啉 [(R)-NMSal] 引起的 AChE 抑制。结果表明，(R)-NMSal 对 AChE 活性有显著影响，且抑制作用是可逆的。所开发的方法为 AChE 抑制测定提供了一种新途径，这对于理解神经毒素诱导的神经退行性疾病的机制非常有益。
