P1AP.10 - pH Imaging of Ion Diffusion at Laminar Flow Interface and Estimation of Diffusion Coefficients
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- P-1 - Applications of Chemical Sensors
- K. Miyamoto, S. Naito, C. Werner, T. Yoshinobu - Department of Electronic Engineering, Tohoku University, Sendai (Japan), S. Uno - Department of Electrical and Electronic Engineering, Ritsumeikan University, Shiga (Japan)
- 454 - 455
A chemical imaging sensor, which is able to visualize the pH distribution, was combined with a Yshaped microfluidic channel. HCl was injected from one inlet and various solutions of chlorides with different cations were injected from the other inlet to form a laminar flow in the channel. The pH distribution was visualized at the laminar flow interface, where protons and cations were exchanged by diffusion. The apparent diffusion coefficient was calculated by fitting the change of pH distribution to the diffusion equation, which showed a clear dependence on the size of cations and fell between the diffusion coefficient of protons and that of cations. This result demonstrated the possibility of discriminating ions based on the measurement of their diffusivity by the chemical imaging sensor.