Nano Drug Delivery Research Center, Kermanshah University of Medical Sciences, P.O. Box 6714967346, Kermanshah, Iran.
Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, P.O. Box 1419733131, Tehran, Iran.
Mikrochim Acta. 2017 Dec 18;185(1):59. doi: 10.1007/s00604-017-2570-z.
The authors describe an electrochemical method for aptamer-based determination of insulin at femtomolar concentrations. The surface of a screen printed electrode was modified with ordered mesoporous carbon that was chemically modified with 1,3,6,8-pyrenetetrasulfonate (TPS). The amino-terminated aptamer was then covalently linked to TPS via reactive sulfonyl chloride groups. Subsequently, the redox probe Methylene Blue (MB) was interacted into the aptamer. The MB-modified binds to insulin and this results in the release of MB and a decreased signal as obtained by differential pulse voltammetry, best at a working voltage of -0.3 V (versus silver pseudo-reference electrode). Insulin can be quantified by this method in the 1.0 fM to 10.0 pM concentration range, with a 0.18 fM limit of detection (at 3σ/slope). The assay was applied to the determination of insulin in spiked human serum samples. The method is highly sensitive, selective, stable, and has a wide analytical range. Graphical abstract The surface of a screen printed electrode was modified with ordered mesoporous carbon-1,3,6,8-pyrenetetrasulfonate. The amino-terminated aptamer was then linked to the 1,3,6,8-pyrenetetrasulfonate. Then, the Methylene Blue was interacted into the aptamer. The modified electrode was applied to the determination of insulin.
作者描述了一种电化学方法，用于在飞摩尔浓度下基于适配体的胰岛素测定。通过化学修饰的 1,3,6,8-四磺基苯（TPS）对丝网印刷电极的表面进行修饰，用 TPS 对有序介孔碳进行化学修饰。然后，将氨基末端的适配体通过反应性磺酰氯基团共价连接到 TPS 上。随后，将氧化还原探针亚甲蓝（MB）与适配体相互作用。MB 修饰物与胰岛素结合，这导致 MB 的释放和通过差分脉冲伏安法获得的信号减少，在工作电压为-0.3 V（相对于银伪参比电极）时最佳。通过该方法可以在 1.0 fM 至 10.0 pM 的浓度范围内定量胰岛素，检测限为 0.18 fM（在 3σ/斜率处）。该测定法应用于人血清样品中胰岛素的测定。该方法具有高灵敏度、选择性、稳定性和宽的分析范围。
