Department of Chemistry, University of Isfahan, Isfahan, 81746-73441, Iran.
Biosens Bioelectron. 2012 Mar 15;33(1):184-9. doi: 10.1016/j.bios.2011.12.050. Epub 2012 Jan 3.
The present manuscript describes a label free electrochemical aptasensor for the detection of sodium diclofenac (DCF). In order to construct the biosensor, the amino-functionalized diclofenac binding aptamer (DBA) was covalently immobilized on the surface of the glassy carbon electrode (GCE). The conformation of the DBAs on the surface of the electrode is changed when this is exposed to different concentrations of DCF. The introduction of DCF induces an alteration in the conformation of the surface immobilized DBA and causes a decrease in the charge transfer resistance of the aptasensor. However, the charge transfer resistance is increased by incubation of GCE/DBA/DCF in the secondary DBA. The changes in the charge transfer resistance have been monitored using the voltammetric and electrochemical impedance spectroscopic (EIS) techniques. The aptasensor shows two different linear dynamic ranges over 0-5.0 μM and 10 μM to 1mM, and the sensitivity of 15.7 kΩ μM(-1) and detection limit of 2.7 × 10(-7)M were obtained. The validity of the method and applicability of the aptasensor were successfully evaluated by detection of DCF in a blood serum sample without interference from the sample matrix. Furthermore, the aptasensor has shown good stability.
本研究描述了一种用于检测双氯芬酸钠（DCF）的无标记电化学适体传感器。为了构建生物传感器，将氨基功能化的双氯芬酸钠结合适体（DBA）共价固定在玻碳电极（GCE）的表面。当暴露于不同浓度的 DCF 时，DBAs 在电极表面的构象会发生变化。DCF 的引入会导致表面固定的 DBA 构象发生改变，并导致适体传感器的电荷转移电阻降低。然而，通过在二次 DBA 中孵育 GCE/DBA/DCF，电荷转移电阻会增加。使用伏安法和电化学阻抗谱（EIS）技术监测电荷转移电阻的变化。该适体传感器在 0-5.0 μM 和 10 μM 至 1mM 范围内呈现出两种不同的线性动态范围，灵敏度为 15.7 kΩ μM(-1)，检测限为 2.7 × 10(-7)M。该方法的有效性和适体传感器的适用性已通过在无样品基质干扰的情况下检测血清样品中的 DCF 得到成功评估。此外，该适体传感器表现出良好的稳定性。
