A novel design of nanochannel structure in a micro–nanofluidic preconcentrator for electrokinetic ion enrichment

Abstract

Since the concentration of target molecules contained in most reagents in analytical chemistry experiments is lower than the minimum concentration required for subsequent detection, it is necessary for sample enrichment. Electrokinetic trapping that utilizes the principle of ion concentration polarization to achieve biomacromolecular enrichment is the most efficient. In this paper, based on the Poisson-Nernst-Plank equation, a novel design of nanochannel structure in a micro-nanofluidic preconcentrator for electrokinetic ion enrichment is carried out by numerical simulation. The results show that the enrichment process can be divided into three stages: enrichment generation, enrichment promotion and enrichment breakdown when the applied voltage is increased. Importantly, by comparing the six different structure nanochannels (straight line type, square wave type, rectangular type, circle type, zigzag type and multi-wave type), we found that the enrichment ratio produced by the rectangular nanochannel is the highest of the six nanochannels, which is 20.7 times. Rectangular nanochannel requires the lowest applied voltage to achieve the highest enrichment ratio. This work provides a novel design method and theoretical basis for the design of detection equipment in ultra-low concentration molecular detection tasks.

Self-diffusion in nanofluids of nonelongated particles in the dilute limit

“…Up to the authors knowledge, there is no previous work determining the full effect (hydraulic and thermal) on kinematic irreversibilities due to particles collisions for suspensions of nonspherical particles. In addition, the new insight reported herein might provide useful information to take advantage in some other disciplines, such as [14].…”

Experimental optimization of machining GH4145 by atomizing discharge ablation milling

“…As the atomization amount increases, the MRR first increases and then decreases, indicating an optimal atomization amount. With the increase of atomization amount, the number of liquid particles that undergo vaporization phenomenon after being heated between the electrodes increases, which generates a significant chip removal force on the particles eroded between the electrodes, thereby promoting the improvement of MRR; However, excessive liquid particles [33,34] mean not only a decrease in the oxygen medium entering the inter-electrode but also an increase in the liquid phase medium that cannot be wholly vaporized between the electrode, resulting in a decrease in MRR. It can also be seen that MRR increases with the increase of oxygen pressure, discharge current, and duty ratio.…”