Faculty of Chemistry, Kharazmi University, Tehran, Iran.
Faculty of Chemistry, Kharazmi University, Tehran, Iran.
Mater Sci Eng C Mater Biol Appl. 2017 Apr 1;73:700-708. doi: 10.1016/j.msec.2016.12.119. Epub 2016 Dec 26.
For the first time, gold nanostars (GNS) were applied for electrostatic and covalent immobilizing a thiol modified Dopamine aptamer on the pencil graphite electrode and signal amplification. Dopamine aptamer was immobilized on the gold nanostars through electrostatic interaction between negatively charged phosphate groups of aptamer and positively charged gold nanostars and AuS well known covalent interaction. In the presence of Dopamine in the test solution, the charge transfer resistance (R) on the electrode surface increased with the increase of the Dopamine concentration due to specific interaction between Dopamine aptamer and Dopamine molecules, which made a barrier for electrons and inhibited the electron-transfer. So, the proposed approach showed a high sensitivity and a wide linearity to Dopamine in the range from 1.0 (±0.1) to 100.0 (±0.3) ngL (ppt) with detection and quantification limits of 0.29 (±0.10) and 0.90 (±0.08) ngL (ppt), respectively. Finally, the sensor was successfully used for determination of Dopamine in biological (human blood plasma and urine) samples. The results open up the path for manufacturing cost effective aptasensors for other biomedical applications.
首次将金纳米星（GNS）应用于静电和共价固定硫醇修饰的多巴胺适体在铅笔石墨电极上，并进行信号放大。多巴胺适体通过适体的负电荷磷酸基团与带正电荷的金纳米星之间的静电相互作用以及众所周知的 AuS 共价相互作用固定在金纳米星上。在测试溶液中存在多巴胺的情况下，由于多巴胺适体与多巴胺分子之间的特异性相互作用，电极表面的电荷转移电阻（R）随着多巴胺浓度的增加而增加，这为电子提供了障碍并抑制了电子转移。因此，该方法对多巴胺的检测范围从 1.0（±0.1）至 100.0（±0.3）ngL（ppt）具有高灵敏度和宽线性，检测限和定量限分别为 0.29（±0.10）和 0.90（±0.08）ngL（ppt）。最后，该传感器成功地用于生物（人血浆和尿液）样品中多巴胺的测定。这些结果为制造用于其他生物医学应用的具有成本效益的适体传感器开辟了道路。
