Fabrication of nanotextured electrodes for electrochemical sensors towards medical applications

Details

Supervisors

Raskin, Jean-Pierre

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil électromécanicien, à finalité spécialisée: mécatronique

Abstract

Venous thromboembolism (VTE) is a medical condition that arises when a blood clot develops in a vein. It is a common cardiovascular disease (∼ 700 per 100 000,death rates up to 40%) difficult to diagnose due to its non-specific symptoms [68]. A strategy to detect the risks of VTE is the measure of the D-dimer level in a blood sample. Currently, there is a lack of reliable and affordable point-of-care assays to diagnose the risks of VTE.This master’s thesis is part of a research project aimed at developing a reliable and affordable D-dimer point-of-care electrochemical biosensor. The sensor’s sensitivity is a crucial aspect of the design, and it depends on the charge-transfer resistance of the biosensor electrode. This work contributes to this research project by investigating the impact of the deposition of gold nanoparticles on the charge-transfer resistance. In the scope of this thesis, the electrophoretic deposition and the drop casting of gold nanoparticles were used to modify graphite ink electrode surfaces. Additionally, a characterization method using scanning electron microscope images (SEM) was developed. Lastly, electrochemical impedance spectroscopy measurements (EIS) were used to evaluate the impact of the deposition process on the charge-transfer resistance. It was demonstrated that the electrophoretic deposition of AuNPs works at high voltages (27V). However, the process damaged the graphite ink electrode. At lower voltages, the electrophoretic deposition process did not have a significant influence on the amount of deposited AuNPs. The drop casting method, however, could be performed on graphite ink electrodes but the method presents limits in terms of reproducibility. A decrease of the charge-transfer resistance of up to 80% was observed for electrodes modified with AuNPs. Finally, the EIS measurements presented several issues. Multiple solutions to those issues were suggested and would need to be tested in future work.