***Archived: This is a past project, it is not on offer at the moment!***
Introduction
Since their discovery, carbon nanotubes have played an important role in many different fields. It is due to their distinct physical properties such as high electrical conductivity, chemical stability and mechanical strength. The unique electronic properties of these materials have been exploited in electrochemistry to detect a wide range of biologically relevant species for the realization of low-cost, portable, point-of-care bio-devices. One of the most exciting and recent usage is the fusion of carbon nanotubes with bio-probes – typically proteins and DNA oligos – for ultrasensitive nano-biosensors. In fact, the ability of carbon nanotubes to promote electron-transfer reactions of many compounds at low potentials make them ideal for the preparation of chips expexcially for medical purposes. Moreover, it is also well known that if non nano-structured electrodes results in good sensitivity only in mM range, carbon nanotube-based electrodes reach detection limits enabling sensing in the µM range that is the physiological concentration range of target metabolites and drugs in human serum.
The Master Project
It is still under debate in literature the role of carbon nanotube sidewalls and tips on the electro-activity of nano-devices. In this project, sensor performances of multi-walled carbon nanotubes directly grown on silicon wafer via chemical vapor deposition were investigated in order to characterize the best tube treatment and orientation that can optimize the sensing. Cyclic voltammetry was performed to identify the nano-fabrication more suitable for biosensing purposes. The targets used were potassium ferricyanide, for its simple and well defined response at carbon materials, and hydrogen peroxide, because it is of crucial importance in biosensing applications. Randomly oriented nanotubes were chosen in order to investigate the effect of treatments on the tube walls. The analysis of carbon nanotube activations on tips was performed by using densely packed vertical nanotubes. Contact angles were measured to evaluate the change of wettability after treatments. Then, electrochemical measurements of multiple oriented nanotubes were carried out. As optimized nano/bio/chip interfaces are required to develop apposite devices for detecting biomarkers, the electrochemistry of a cancer drug was investigated by using the carbon nanotube-based electrode with the best sensing performances.
Tasks:
- Micro-fabrication of carbon nanotube-based electrodes
- Acquiring electrochemical signals from the nano-structured electrodes
- Computing the sensing performances obtained by nano-structuring
- Testing the nano-structured electrode response in biomolecule monitoring
Requirements:
- Basic knowledge on sensors
- Basic Knowledge on nanotechnology
- Experience with electrical measurements with lab equipments
- Interest in nanofabrication and electrochemistry
This project was supervised by Sandro Carrara.
***Archived: This is a past project, it is not on offer at the moment!***