For point-of-care protein-based diagnosis, the sensitivity of a device is limited by the small quantities of proteins contained within a sample. The aim of this project is to utilise a method of protein separation termed 'isoelectric focusing' (IEF) along with electrochemical control of the local pH to perform simultaneous purification, preconcentration and separation of proteins within a small sample based on their isoelectric points (PI). The finished device will combine these techniques on a printed circuit board (PCB) platform, lab-on-PCB, and will enable the efficient diagnosis for a broad range of health conditions, ranging from cancer to infectious disease.
Isoelectric focusing ordinarily refers to the macroscopic separation of proteins along a pH gradient due to their isoelectric point (the pH at which the carboxyl/amine groups of a protein are neutralised) with an applied electric field. By producing a mechanism through which the local pH may be precisely controlled and maintained, the proposed device will be able to perform isoelectric focusing of specific proteins based on the current or voltage supplied to electrodes. In this innovative approach, we aim to miniaturise these processes and utilise microfluidic techniques within a PCB format to preconcentrate proteins for analysis.
The foreseeable landmark tasks will be as follows:
Assess the current state of the art for both techniques;
Simulate existing techniques using COMSOL Multiphysics;
Perform experiments based on the results of the simulations;
Integrate the knowledge gained into designing, simulating, building and testing a prototype which combines IEF with a method of local pH control in a miniaturised PCB platform.