Foley Kyle J, Shan Xiaonan, Tao N J
Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287, USA.
Anal Chem. 2008 Jul 1;80(13):5146-51. doi: 10.1021/ac800361p. Epub 2008 May 17.
We demonstrate here a surface impedance imaging technique based on sensitive dependence of surface plasmon resonance (SPR) on local surface charge density. By applying a potential modulation to a sensor surface, we are able to simultaneously obtain three images: the dc component and the amplitude and phase of the ac component. The dc image measures local molecular binding activity on the surface, as found in the conventional SPR imaging technique, and the ac images are directly related to the local impedance of the surface. Our experimental data can be analyzed quantitatively in terms of the simple free electron gas model for the sensor surface and the Randles equivalent circuit model for interfacial impedance.
我们在此展示了一种基于表面等离子体共振（SPR）对局部表面电荷密度的敏感依赖性的表面阻抗成像技术。通过对传感器表面施加电势调制，我们能够同时获得三张图像：直流分量以及交流分量的幅度和相位。直流图像测量的是表面上的局部分子结合活性，这与传统的SPR成像技术中所发现的一致，而交流图像则直接与表面的局部阻抗相关。我们的实验数据可以根据传感器表面的简单自由电子气模型和界面阻抗的兰德尔等效电路模型进行定量分析。
