Mikula Edyta, Wyslouch-Cieszynska Aleksandra, Zhukova Liliya, Verwilst Peter, Dehaen Wim, Radecki Jerzy, Radecka Hanna
Institute of Animal Reproduction and Food Research Polish Academy of Science, Tuwima 10, 10-748 Olsztyn, Poland.
Curr Alzheimer Res. 2017;14(3):345-351. doi: 10.2174/1567205013666161108110542.
Alzheimer's disease (AD) is the most common form of dementia. The process of AD can begin 20 years before any symptom of cognitive loss. Thus, the development of systems for early diagnosis and prevention is very important. The mechanism of AD is still under debate. Nevertheless, higher levels of glycated albumin in cerebrospinal fluid and plasma are observed in AD patients. Therefore, glycated albumin could be a biomarker of AD development.
Electrochemical biosensor for direct determination of glycated albumin was based on thiol derivative of pentetic acid (DTPA) complex with Cu(II) created on gold electrode surface. His-tagged domains of Receptors for Advanced Glycation End Products (RAGE) were applied as analytical active element for glycated albumin recognition. The binding of glycated albumin by His6- RAGE domains was monitored using Osteryoung square - wave voltammetry.
Electrodes modified with His6 - RAGE VC1 natural domain generated decrease of Cu(II) redox currents in the presence of glycated albumin. Human albumin, Aβ 1-40 and S100B protein caused negligible influence on biosensors responses towards glycated albumin. The detection limits were: 2.3 pM, 1.1 pM, 2.9 pM and 3.1 pM in the presence of: buffer, buffer + albumin, buffer + S100B, buffer + Aβ1-40 , respectively.
The presented electrochemical biosensor was successfully applied for the determination of glycated albumin. Considering analytical parameters such as good selectivity and sensitivity in pM range, biosensor could be recommended as an analytical tool for medical samples analysis.
阿尔茨海默病（AD）是最常见的痴呆形式。AD的进程可能在出现任何认知丧失症状的20年前就已开始。因此，开发早期诊断和预防系统非常重要。AD的发病机制仍在争论中。然而，在AD患者的脑脊液和血浆中观察到糖化白蛋白水平较高。因此，糖化白蛋白可能是AD发展的生物标志物。
用于直接测定糖化白蛋白的电化学生物传感器基于在金电极表面形成的与铜（II）络合的喷替酸（DTPA）硫醇衍生物。晚期糖基化终产物受体（RAGE）的His标签结构域用作糖化白蛋白识别的分析活性元件。使用奥斯特杨方波伏安法监测His6-RAGE结构域与糖化白蛋白的结合。
用His6-RAGE VC1天然结构域修饰的电极在存在糖化白蛋白的情况下，铜（II）氧化还原电流降低。人白蛋白、Aβ1-40和S100B蛋白对生物传感器对糖化白蛋白的响应影响可忽略不计。在存在以下物质时的检测限分别为：2.3 pM、1.1 pM、2.9 pM和3.1 pM，分别对应：缓冲液、缓冲液+白蛋白、缓冲液+S100B、缓冲液+Aβ1-40。
所展示的电化学生物传感器成功应用于糖化白蛋白的测定。考虑到诸如在pM范围内具有良好的选择性和灵敏度等分析参数，该生物传感器可推荐作为医学样品分析的工具。
