Effects of electrophoresis and electroosmotic flow on ion enrichment in micro-nanofluidic preconcentrator

In this paper, we demonstrate the effects of electrophoresis (EP) and electroosmotic flow (EOP) on ion enrichment in micro-nanofluidic preconcentrator via numerical simulation. The difference of sample fluxes resulted from EP and EOP at the micro-nano interface is defined to distinguish the contributions of EOF and EP to ion enrichment. The influences of several parameters related to the enrichment ratio are investigated in detail. The results show that the enrichment ratio can be improved via enhancing the difference. To increase the difference, several proposals are presented, including raising imposed electric potential, increasing surface charge density and enhancing fluid viscosity.