Electrothermal active control of preconcentrated biomolecule plugs

TL;DR

This paper introduces an electrothermal stirring method in microfluidics to actively control the position of biomolecule preconcentration plugs, improving detection sensitivity and binding efficiency.

Contribution

It presents a novel microfluidic platform combining CP and ET stirring for dynamic control of biomolecule localization.

Findings

Active control of biomolecule plug position achieved

Enhanced detection sensitivity demonstrated

Improved binding kinetics observed

Abstract

Concentration polarization (CP) based biomolecule preconcentration is highly effective in enhancing the detection sensitivity, yet fails to precisely and dynamically control the location of the preconcentrated biomolecule plug to ensure overlap with the sensing region (e.g. immobilized molecular probes). Here, we used electrothermal (ET) stirring as a means of controlling the location of a preconcentrated biomolecule plug. The applied microfluidic device consisted of a Nafion membrane to induce the CP, and an array of individually addressable microscale heaters for active local ET stirring. The experimental results demonstrated that such a novel platform enabled active control of the location of the preconcentrated plug of target biomolecules, ensuring its overlap with the functionalized microparticles, ultimately yielding enhanced detection sensitivity and binding kinetics. This was demonstrated using avidin-biotin particles as a simple bead-based bioassay model.