Diffusiophoresis의 Debye-layer 효과를 이용한 크기 기반 나노입자 분리

Abstract

Particle separation, including DNA, proteins, and viruses, is one of the most fundamental technologies in the biological, analytical, and biomedical fields. To date, a variety of separation techniques have been reported in the literature but most of them are limited to microparticles (> 1 μm). In other words, the same separation techniques are not applicable to the separation of nanoparticles (< 1 μm) because of the different order of size. In this context, microfluidic nanoparticle separation has still been actively studied but it remains a challenge. Here, we propose a novel diffusiophoresis-based separation technique that utilizes the effect of Debye layer thickness on diffusiophoresis, which is a colloidal migration phenomenon induced by a solute gradient. It is typical that particles migrate toward high or low concentration and their migration direction and mobility can vary, depending on their size. We fabricate a microfluidic diffusiophoresis platform to generate and control solute gradients on a chip and then demonstrate that the platform successfully separates a nanoparticle mixture consisting of 50 nm and 500 nm, 20 nm and 200 nm, and 40 nm and 200 nm, respectively. We will present more experimental and theoretical results during the conference for sure.