Derikvand Hanieh, Roushani Mahmoud, Abbasi Amir Reza, Derikvand Zohreh, Azadbakht Azadeh
Department of Chemistry, Khorramabad Branch, Islamic Azad University, Khorramabad, Iran.
Department of Chemistry, Ilam University, Ilam, Iran.
Anal Biochem. 2016 Nov 15;513:77-86. doi: 10.1016/j.ab.2016.06.013. Epub 2016 Jun 26.
In this work, a novel sensing nanocomposite with highly dispersed platinum nanoparticles (PtNPs) on carbon nanotubes (CNTs) functionalized with polyethyleneimine (PEI) has been developed as a platform for immobilization of diclofenac (DIF) aptamer. PtNPs/PEI/CNTs nanocomposite provided abundant NH2 groups for the immobilization of DIF-specific aptamer. Attachment of DIF-aptamer at the surface of modified electrode was performed through the formation of phosphoramidate bonds between the amino group of PEI and the phosphate group of the aptamer at the 5' end. Nickel hexacyanoferrate (NiHCF) as signal probe was electrodeposited at the surface of nanocomposite by a simple electrodeposition method including two consecutive procedures. Under optimal conditions, DIF was detected by impedance spectroscopy (EIS) quantitatively. By adding DIF as the target at the surface of modified electrode, the aptamer specifically binds to DIF and its end folds into a DIF-binding junction, which leads to retarding the interfacial electron transfer of the probe at the surface of modified electrode. Sensitive quantitative detection of DIF was carried out by monitoring the increase of charge transfer resistance (Rct) by increasing the DIF concentration. The proposed aptasensor showed a good detection range from 10 to 200 nM with an unprecedented detection limit of 2.7 nM.
在这项工作中，已开发出一种新型传感纳米复合材料，其在经聚乙烯亚胺（PEI）功能化的碳纳米管（CNT）上具有高度分散的铂纳米颗粒（PtNP），作为固定双氯芬酸（DIF）适配体的平台。PtNP/PEI/CNT纳米复合材料为固定DIF特异性适配体提供了丰富的NH₂基团。通过在PEI的氨基与适配体5'端的磷酸基团之间形成磷酰胺键，将DIF适配体附着在修饰电极表面。作为信号探针的六氰合铁酸镍（NiHCF）通过一种简单的电沉积方法（包括两个连续步骤）电沉积在纳米复合材料表面。在最佳条件下，通过阻抗谱（EIS）对DIF进行定量检测。通过在修饰电极表面加入作为靶标的DIF，适配体特异性结合DIF，其末端折叠成DIF结合连接体，这导致修饰电极表面探针的界面电子转移受阻。通过监测随着DIF浓度增加电荷转移电阻（Rct）的增加，对DIF进行灵敏的定量检测。所提出的适配体传感器显示出良好的检测范围，为10至200 nM，检测限低至2.7 nM，这是前所未有的。
