Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
Analyst. 2018 Sep 24;143(19):4756-4763. doi: 10.1039/c8an01457d.
Alzheimer's disease (AD) affects middle- and old-age populations, and causes loss of brain weight, degradation of brain functions and memory loss. So the fast and accurate detection of AD related markers is highly important in diagnosis. We report in this work the detection of Cu2+ and dopamine (DA), which are markers related to AD, by direct electrochemistry (DEC) and electrochemiluminescence (ECL) using a silica nanochannel membrane modified glassy carbon electrode (SNM/GCE). By DEC, the detection of both Cu2+ and DA in buffer solutions was achieved with a wide linear range and a low limit of detection (LOD). The determination of DA was also achieved in terms of its quenching effect on the ECL of the tris(2,2'-bipyridyl)ruthenium(ii)/tri-n-propylamine co-reactant system in both intensity and image modes, yielding a particularly high sensitivity in the former case. In comparison with a bare GCE, the analytical sensitivity and selectivity of the SNM/GCE were superior, most likely due to the analyte pre-concentration and permselective effects of the SNM. Moreover, given that the SNM consists of perpendicular channels with a negatively charged surface, high channel density (ca. 7.5 × 1012 cm-2) and uniform size (ca. 2.3 nm in diameter), it displays a high molecular permeability and meanwhile a high selectivity in terms of molecular size and charge. So the SNM/GCE exhibited an excellent anti-fouling ability in biofluids, such as human blood and artificial cerebrospinal fluid, suppressing effectively the interference of coexisting substances (such as cells, proteins, and other big and small molecules) and providing excellent signal stability.
阿尔茨海默病（AD）影响中老年人，并导致脑重量减轻、脑功能退化和记忆力丧失。因此，快速准确地检测 AD 相关标志物对诊断非常重要。我们在这项工作中报告了使用二氧化硅纳米通道膜修饰的玻碳电极（SNM/GCE）通过直接电化学（DEC）和电化学发光（ECL）检测与 AD 相关的 Cu2+和多巴胺（DA）。通过 DEC，在缓冲溶液中实现了对 Cu2+和 DA 的宽线性范围和低检测限（LOD）的检测。还通过测定 DA 对三（2,2'-联吡啶）钌（ii）/三正丙胺共反应物体系的 ECL 的猝灭效应，以强度和图像两种模式实现了 DA 的测定，前者的灵敏度特别高。与裸 GCE 相比，SNM/GCE 的分析灵敏度和选择性更高，这可能归因于 SNM 的分析物预浓缩和选择透过性效应。此外，由于 SNM 由带负电荷表面的垂直通道组成，具有高通道密度（约 7.5×1012cm-2）和均匀的尺寸（约 2.3nm 直径），它表现出高的分子通透性和分子尺寸和电荷的高选择性。因此，SNM/GCE 在生物流体（如人血和人工脑脊液）中表现出优异的抗污能力，有效地抑制了共存物质（如细胞、蛋白质和其他大分子和小分子）的干扰，并提供了优异的信号稳定性。
