AbstractThe authors report on an amperometric method for the determination of glycoprotein by using an aptamer as the bioreceptor. The detection scheme is making use of aggregated citrate-capped silver nanoparticles (AgNPs) on a gold electrode. Aggregation is accomplished by addition of 4-mercaptophenylboronic acid (MPBA) which acts as a cross-linker due to the formation of Ag-S bonds and of boronate esters. A thiolated DNA aptamer was then attached to the electrode in order to capture glycoprotein. Once captured, the glycoprotein reacts with MPBA through the formation of boronate esters. The electrochemical signal is thus amplified by the formation of a network of AgNPs which act as redox reporters. To demonstrate the feasibility of the method, prostate specific antigen (PSA) was chosen as a model analyte. The detection limit for PSA is as low as 0.2 pg mL−1. In our preception, this method provides a powerful tool for studying the glycan function in biological and physiological processes. Graphical abstractSchematic of the electrochemical method for the detection of glycoprotein. It is based on 4-mercaptophenylboronic acid (MPBA)-induced in situ formation of citrate-capped silver nanoparticle (AgNP) aggregates as the redox reporters. The MPBA molecules act as the cross-linkers of AgNP assembly based on the formation of Ag-S bonds and on boronate ester covalent interactions.

中文翻译：

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基于4-巯基苯基硼酸诱导的银纳米颗粒原位聚集的电化学糖蛋白适体传感器

摘要 作者报道了一种以适体为生物受体测定糖蛋白的电流法。检测方案是在金电极上使用聚集的柠檬酸盐封端的银纳米粒子 (AgNPs)。聚集是通过添加 4-巯基苯基硼酸 (MPBA) 实现的，MPBA 由于形成 Ag-S 键和硼酸酯而起到交联剂的作用。然后将硫醇化 DNA 适体连接到电极上以捕获糖蛋白。一旦被捕获，糖蛋白就会通过硼酸酯的形成与 MPBA 反应。因此，通过形成充当氧化还原报告分子的 AgNPs 网络来放大电化学信号。为了证明该方法的可行性，选择前列腺特异性抗原 (PSA) 作为模型分析物。PSA 的检测限低至 0.2 pg mL-1。在我们看来，这种方法为研究生物和生理过程中的聚糖功能提供了强大的工具。图解 检测糖蛋白的电化学方法示意图。它基于 4-巯基苯基硼酸 (MPBA) 诱导原位形成柠檬酸盐封端的银纳米颗粒 (AgNP) 聚集体作为氧化还原报告分子。MPBA 分子作为 AgNP 组装的交联剂，基于 Ag-S 键的形成和硼酸酯共价相互作用。它基于 4-巯基苯基硼酸 (MPBA) 诱导原位形成柠檬酸盐封端的银纳米颗粒 (AgNP) 聚集体作为氧化还原报告分子。MPBA 分子作为 AgNP 组装的交联剂，基于 Ag-S 键的形成和硼酸酯共价相互作用。它基于 4-巯基苯基硼酸 (MPBA) 诱导原位形成柠檬酸盐封端的银纳米颗粒 (AgNP) 聚集体作为氧化还原报告分子。MPBA 分子作为 AgNP 组装的交联剂，基于 Ag-S 键的形成和硼酸酯共价相互作用。