Numerical Modeling and Analysis of magnetic nanoparticle enhanced mixing, separation and detection in a microfluidic lab-on-a-chip systems
From LabAutopedia
Title: Numerical Modeling and Analysis of magnetic nanoparticle enhanced mixing, separation and detection in a microfluidic lab-on-a-chip systemsAuthor(s)name and affiliation: Ahsan Munir, Jianlong Wang, Zanzan Zhu & Susan Zhou
Microfluidics & Bio-Nanotechnology Laboratory, Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609
Abstract:Microfluidics together with nanotechnology is playing a key role in the development of Lab-on-chip devices that can be used to detect target biomolecules for in-field testing and analysis. These devices are now being realized for medical diagnostics in the hospital, forensic analysis of DNA at site of crime, and environmental analysis at a pollution site. The performance of these devices greatly depends on the separation and detection efficiency of target biomolecule which can be enhanced by utilizing magnetic field together with magnetic nanoparticles on chip. In this work numerical simulation technique is used to investigate wide range of design parameters involved in magnetically actuated mixing, separation and detection processes.
Mixing of magnetic nanoparticles with the target biomolecule is critical for effectively separating labeled biomolecules from bulk sample for further analysis. A numerical prototype that uses time-dependent magnetic actuation for mixing the label target biomolecule with magnetic nanoparticles was developed. It was shown that it is possible to generate periodic magnetic forces that can make the magnetic nanoparticles oscillate in different directions. This oscillation of magnetic nanoparticles causes agitation in the surrounding fluid thus improving the mixing of the biomolecules and magnetic nanoparticles in the microchannel. Effect of magnetic forces, switching frequency of magnetic field on different sizes of magnetic nanoparticles was quantitatively investigated and the optimized mixing time was also proposed.
Separation of magnetically tagged target biomolecule from bulk sample was further studied using finite element model and it was found that parameters such as fluid velocity, nanoparticle diameter, magnetic field and its orientation had significant effect on overall separation performance.
Final step for these integrated devices require efficient and faster detection of target biomolecules. Therefore, in order to reduce the detection time, a novel strategy of bringing more target biomolecules on the detection surfaces using magnetic forces was demonstrated. The dynamics and kinetics of surface-based binding responsible for detection process was studied It was found that the introduction of magnetic actuation overcomes the diffusion limitation in the microchannel and enhances the detection performance.
The simulation performed using the developed multi-physics models at the concept stage provided an excellent estimate of the potential to use magnetic nanoparticles for integrated lab-on-chip devices as well as investigate wide range of design parameters that will be useful in designing and developing more efficient handheld devices for point-of-care applications.
