Vlassiouk Ivan, Kozel Thomas R, Siwy Zuzanna S
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
J Am Chem Soc. 2009 Jun 17;131(23):8211-20. doi: 10.1021/ja901120f.
Recently reported nanofluidic diodes with highly nonlinear current-voltage characteristics offer a unique possibility to construct different biosensors. These sensors are based on local changes of the surface charge on walls of single conical nanopores induced by binding of an analyte. The analyte binding can be detected as a change of the ion-current rectification of single nanopores defined as a ratio of currents for voltages of one polarity, and currents for voltages of the opposite polarity. In this article, we provided both modeling and experimental studies of various biosensing routes based on monitoring changes of the rectification degree in nanofluidic diodes used as a biosensing platform. A prototype of a sensor for the capsular poly gamma-D-glutamic acid (gammaDPGA) from Bacillus anthracis is presented. The nanopore used for the sensing was locally modified with the monoclonal antibody for gammaDPGA. The proof of principle of the rectification degree-based sensing was further shown by preparation of sensors for avidin and streptavidin. Our devices also allowed for determination of the isoelectric point of the minute amounts of proteins immobilized on the surface.
最近报道的具有高度非线性电流-电压特性的纳米流体二极管为构建不同的生物传感器提供了独特的可能性。这些传感器基于分析物结合引起的单个锥形纳米孔壁表面电荷的局部变化。分析物结合可以通过检测单个纳米孔的离子电流整流变化来检测，该变化定义为一种极性电压下的电流与相反极性电压下的电流之比。在本文中，我们基于监测用作生物传感平台的纳米流体二极管中整流程度的变化，对各种生物传感途径进行了建模和实验研究。展示了一种用于炭疽芽孢杆菌荚膜聚γ-D-谷氨酸（γDPGA）的传感器原型。用于传感的纳米孔用γDPGA单克隆抗体进行了局部修饰。通过制备抗生物素蛋白和链霉抗生物素蛋白的传感器，进一步证明了基于整流程度传感的原理。我们的装置还能够测定固定在表面的微量蛋白质的等电点。
