An improved extracellular ion fluxes measurement system based on Nernst-Planck equation

•Based on Nernst-Planck equation, we proposed an innovative extracellular ion fluxes measurement method to correct the influence of electric field change on extracellular ion fluxes measurement.•Based on the proposed theory, an experimental prototype is designed to correct the influence of electric field.•This study proposed to use the two-stage differential and amplification method to obtain weak voltage signals caused by the changes of ion concentration gradient, namely, the two-stage differential amplification was carried out through the pre-amplifier and the signal conditioning circuit. Extracellular ion fluxes measurement plays an important role in bioelectrophysiology and ionomics. However, it was affected by the extracellular electric field generated by the electrical activity of cells, resulting in a large error in ion fluxes data. We proposed an innovative measurement method based on Nernst-Planck equation and developed a prototype device to correct the influence of electric field change on extracellular ion fluxes measurement. Artificial ion source experiment indicated the prototype system could effectively obtain the weak voltage signal generated by ion concentration gradient changes. Electric field experiment showed that the influence of electric field on ion fluxes measurement mainly occurs in electric field transient changes. By recording of Ca2+ fluxes of wheat seedlings under cyclic illumination/darkness stimulation, this system can effectively correct the influence of electric field change caused by tissue or cell electrical activity on extracellular ion fluxes measurement and obtain more accurate data of ion fluxes.