Highly Effective Protein Concentration and Trapping by Nano-scaled Insulating Dielectrophoresis

  • FU, Junxue (PI)

Project: Research project

Project Details


The aim of this proposal is to increase the number of proteins for biological analysis by concentrating the proteins from the provided sample.

Protein analysis, such as protein sequencing, protein detection and etc., is an important step in biological and medical diagnostics. To obtain the detectable signal, a certain number of proteins are needed. Since there is no chemical method available for protein amplification, protein concentration and trapping is the feasible way to increase the number of proteins being analyzed.

Recent research shows that insulating dielectrophoresis (iDEP) is a promising enrichment technique for proteins, which refers to the movement of proteins towards the large or small electric field gradient in a non-uniform electric field. It is normally performed in a microfluidic channel, where an array of insulating posts are placed in the channel and two external electrodes submerged in the reservoirs. The electric field lines are squeezed between the insulating posts and the field gradient is created around them. The iDEP force exerted on proteins mainly depends on the protein size and polarizability, and magnitude of electric field gradient. To successful trap proteins, a large electric field gradient is required. This requirement comes from the fact that proteins have a small dimension (only a few nanometers) and low polarizability.

To generate the large electric field gradient, a well-known way is to scale down the dimensions of insulating posts and the spacing between adjacent posts to nanometer range. Here we propose to employ oblique angle deposition (OAD) to fabricate nanostructures and integrate them into iDEP devices. OAD can overcome a few difficulties the current fabrication methods are facing, such as the limit of insulating posts dimensions, high cost, difficult process, etc. More significantly, our preliminary simulation shows that, with the dimensions of nanorods made by OAD, the field gradient generated by them is 10 - 10^6 larger than that produced by the reported smallest insulating posts. In this project, protein trapping capability of OAD-based nanostructures will be investigated; and further experiments on iDEP improved protein detection will be carried out.

Most diagnostic centers in Hong Kong mainly focus on bioanalytical and medical applications. Our studies will lead to the development of a simple, low-cost, and highly effective protein concentration and trapping technique by taking advantages of versatile nanostructures made by OAD. We believe that the success of this proposal will facilitate the low-cost bio-analysis and bio-detection chips in the related industry.
Effective start/end date1/09/1428/02/18

UN Sustainable Development Goals

In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This project contributes towards the following SDG(s):

  • SDG 3 - Good Health and Well-being


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