Novel lab-on-a-chip design for biomolecular diagnosis

Abstract

This research thesis was conducted to design and fabricate a novel design of a lab-on-a-chip microfluidic device to enable blood separation and blood analyses at the nanoscale via nanopores integrated into microchannel. Furthermore, the same lab-on-a-chip microfluidic device could be used for blood examination and diagnoses by changing just one step during the fabrication. The development of the novel lab-on-a-chip device able to carry out a range of biomolecular analyses, providing reliable results, incorporates nanochannels obtained via an innovative manufacturing process, combining traditional micro-fabrication methods and electrochemical anodization. The lab-on-a-chip device consists of glass substrate sealed with poly-dimethyl siloxane (PDMS) in which microchannels have been etched. The different metals deposited determined the use of the device. Physical vapor deposition was applied to deposit either aluminium or gold. The aluminium has been anodized inside the microchannel to obtain nanoporous alumina channels. The gold metal has been
used for biosensing experiments. DNA aptamers were attached to the gold using thiol ligands, enabling the detection of ochratoxin-A and A-human thrombin. Cyclic voltammetry and electrochemical impedance spectrometry have been used to detect both biomolecules. The shift of the curve confirms the presence of the biomolecule. When sodium chloride was used to wash away the A-human thrombin, the curve went back to the initial measurement when only the DNA aptamer was present, enabling repeat use of the device.

Date of Award	20 Nov 2019
Original language	English
Awarding Institution	University of Bath
Sponsors	ESF and EPSRC
Supervisor	Davide Mattia (Supervisor) & Pedro Estrela (Supervisor)