title: Plasmonic-based electrochemical impedance spectroscopy: application to molecular binding.
abstract: Plasmonic-based electrochemical impedance spectroscopy (P-EIS) is developed to investigate molecular binding on surfaces. Its basic principle relies on the sensitive dependence of surface plasmon resonance (SPR) signal on surface charge density, which is modulated by applying an ac potential to a SPR chip surface. The ac component of the SPR response gives the electrochemical impedance, and the dc component provides the conventional SPR detection. The plasmonic-based impedance measured over a range of frequency is in quantitative agreement with the conventional electrochemical impedance. Compared to the conventional SPR detection, P-EIS is sensitive to molecular binding taking place on the chip surface and less sensitive to bulk refractive index changes or nonspecific binding. Moreover, this new approach allows for simultaneous SPR and surface impedance analysis of molecular binding processes.
authors: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
authors: Jin
authors: J
authors: Lu
authors: Wei
authors: W
authors: Wang
authors: Shaopeng
authors: S
authors: Wang
authors: Xiaonan
authors: X
authors: Shan
authors: Jinghong
authors: J
authors: Li
authors: Nongjian
authors: N
authors: Tao
mesh_terms: D001665:Binding Sites; D058266:Dielectric Spectroscopy / Q000379:methods*; D020349:Surface Plasmon Resonance