Ag agcl electrode

The three-electrode scheme was employed as shown in Figure 1. The ITO substrate (Qunguan Electronic Technology Co., Ltd., Dongguan, China) was used as the working electrode. The counter electrode was a commercially available platinum foil (Fisher Scientific, Waltham, MA, USA). The reference electrode was an Ag/AgCl electrode (Fisher Scientific, Waltham, MA, USA).
The measurement setup of the microchip is illustrated in Figure 1. In the measurement, a (Fiber-Lite MI-150R, Dolan-Jenner Industries, Boxborough, MA, USA) light source was used to generate the incident light. The polarizer and the analyzer films (Renianus, Guangzhou, China) were used to only allow light with specific polarization to pass. Liquid crystal (Liquid crystal mixture E7 from BOC Sciences, Shirley, New York, NY, USA) filled the wells to sense the change in zeta potentials. The setup was placed under an inverted Olympus I-70 microscope (Olympus Life Science, Tokyo, Japan). In all measurements, we utilized a 20× magnification objective lens with a numerical aperture of 0.4. The transmitted light was detected by a CCD camera (MF603C-CCD from AmScope, Irvine, CA, USA). The captured images were subsequently processed using a MATLAB program to generate a peak-to-peak light-intensity map, which was then converted into a surface potential distribution.