Transport efficiency of biofunctionalized magnetic particles tailored by surfactant concentration

TL;DR

This study investigates how surfactant concentration affects the transport efficiency of biofunctionalized magnetic particles in microfluidic environments, combining theoretical modeling and experimental validation.

Contribution

It introduces a model for tuning particle-surface separation and demonstrates how surfactant levels influence magnetic particle transport in lab-on-chip systems.

Findings

Surfactant concentration controls particle-surface separation distance.

Transport velocity can be modulated by external magnetic fields.

Model and experiments align in predicting particle transport behavior.

Abstract

Controlled transport of surface functionalized magnetic beads in a liquid medium is a central requirement for the handling of captured biomolecular targets in microfluidic lab-on-chip biosensors. Here, the influence of the physiological liquid medium on the transport characteristics of functionalized magnetic particles and on the functionality of the coupled protein is studied. These aspects are theoretically modeled and experimentally investigated for prototype superparamagnetic beads, surface functionalized with green fluorescent protein immersed in buffer solution with different concentrations of a surfactant. The model reports on the tunability of the steady-state particle substrate separation distance to prevent their surface sticking via the choice of surfactant concentration. Experimental and theoretical average velocities are discussed for a ratchet like particle motion induced by a dynamic external field superposed on a static locally varying magnetic field landscape. The developed model and experiment may serve as a basis for quantitative forecasts on the functionality of magnetic particle transport based lab-on-chip devices.