Electrical bias phase sensitive imaging sensor is a kind of electrochemical and elliptic partial optical methods of composite surface characterization methods, real time detection in situ solid-liquid interface electron exchange occurs on the surface of the solid phase change. Application of the sensor, we usually need to impose an external interface potential, however, the potential to change the nature of the surface of the solid phase, affecting the response of the sensor. In order to solve this problem, by nanometer biological optical group, institute of mechanics, Chinese academy of sciences and the university of Lisbon, Portugal, a joint team of chemical and biological chemistry study the influence of external electric potential on the surface of the solid phase, found the relationship between external electric potential quantitative response of the sensor, the results, published online in February 18, in the American chemical society publications in the journal analytical chemistry (Liu, et al., Anal. Chem. 88:3211).

Electrical bias phase sensitive imaging sensor can exert different electrochemical conditions in the surface of solid phase, at the same time with polarized light waves as the detecting light illuminate the surface. Under the mode of total internal reflection, the incident light wave in total reflection on the surface of the solid phase, at this time on the wavelength of the surface of the solid phase modulation, resulting in the change of the reflected light polarization. By comparing the change of light polarization, can derive the tiny changes on the surface of the solid phase, realize the interface thickness is only the ultrathin membrane layer of nanometer level measurement. At present, the sensor has been successfully used in solid-liquid interface real-time monitoring in situ molecular adsorption and the adsorption process. At the interface between solid and liquid, because of the difference of two phase electric potential, will form the spontaneous potential. After applying potential, interface charge balance is broken, the interface of electric potential changes; Molecular adsorption and the adsorption behavior, on the other hand, will also affect the interface of spontaneous potential and leads to the changing nature of the solid phase surface. Therefore, in order to accurately monitor molecules on the surface of the solid phase adsorption and adsorption behavior, you must remove and potential impact on the surface of the solid phase.

Nano biological mechanics by optical research doctoral opportunities and associate professor NiuYu electrical bias phase sensitive imaging sensor was used to study the potential effect on the surface of the solid phase, proved that the solid-liquid interface electric potential change will not only cause the change of liquid refractive index is near interface, also the complex refractive index on the surface of the solid phase modulation, and the impact of these changes for the sensor is not to be ignored, especially for the detection of trace concentrations of small molecules, obtained the external relationship between electric potential and quantitative response of the sensor signals. Through the theoretical calculation of auxiliary by way of the reference signal can effectively eliminate the influence of the electric potential disturbance. The results of electrical bias phase sensitive imaging sensor application have important guiding significance.

The study obtained the ministry of science and technology "973" project "ultrasensitive micro-nano biological chemical sensors integrated autonomous system basic research (2015 cb352100)" and the ministry of science and technology international cooperation is the detection of tumor markers and biological oxygen demand (cod) of cooperative research (2015 dfg32390) on the surface of the new type of modified "support, such as nano biological optics research fellow JinGang presided over by the mechanics.