Choi Young-Bong, Kim Nam-Hyuk, Kim Seung-Hoi, Tae Gun-Sik, Kim Hyug-Han
Department of chemistry, College of Natural Science, Dankook University, Anseo-Dong, Cheonan 330-714, Korea.
Department of biology, College of Natural Science, Dankook University, Anseo-Dong, Cheonan 330-714, Korea.
Sensors (Basel). 2014 Oct 13;14(10):18886-97. doi: 10.3390/s141018886.
By directly coordinating hippuric acid (HA) to the ferrate (Fe) as an electron transfer mediator, we synthesized a Fe-HA complex, which shows a good electrochemical signal and thus enables the electrochemical immunoanalysis for HA. We electrodeposited organic films containing imidazole groups on the electrode surface and then bonded Ni ion (positive charge) to induce immobilization of Fe-HA (negative charge) through the electrostatic interaction. The heterogeneous competitive immunoassay system relies on the interaction between immobilized Fe-HA antigen conjugate and free HA antigen to its antibody (anti-HA). The electric signal becomes weaker due to the hindered electron transfer reaction when a large-sized HA antibody is bound onto the Fe-HA. However, in the presence of HA, the electric signal increases because free HA competitively reacts with the HA antibody prior to actual reaction and thus prevents the HA antibody from interacting with Fe-HA at the electrode surface. This competition reaction enabled an electrochemical quantitative analysis of HA concentration with a detection limit of 0.5 μg mL(-1), and thus allowed us to develop a simple and rapid electrochemical immunosensor.
通过将马尿酸（HA）直接与高铁酸盐（Fe）配位作为电子转移介质，我们合成了一种Fe-HA络合物，该络合物显示出良好的电化学信号，从而能够对HA进行电化学免疫分析。我们在电极表面电沉积含咪唑基团的有机膜，然后结合镍离子（正电荷），通过静电相互作用诱导Fe-HA（负电荷）固定化。异质竞争免疫分析系统依赖于固定化的Fe-HA抗原结合物与其抗体（抗HA）的游离HA抗原之间的相互作用。当大型HA抗体结合到Fe-HA上时，由于电子转移反应受阻，电信号变弱。然而，在HA存在的情况下，电信号会增加，因为游离HA在实际反应之前与HA抗体发生竞争性反应，从而阻止HA抗体与电极表面的Fe-HA相互作用。这种竞争反应实现了HA浓度的电化学定量分析，检测限为0.5μg mL(-1)，从而使我们能够开发出一种简单快速的电化学免疫传感器。
