Feb 3, 2009

PhD: Development and Optimisation of Novel on-chip Nanowire-Based Electrodes for Electrochemical-Based Sensing Applications

The essence of nanoscience and nanotechnology is the investigation and exploitation of novel properties, phenomena and processes, at length scales ranging from 0.2 nanometres (nm) to 100 nm. The nanotechnology group at Tyndall National Institute focuses on development of methods for synthesis, fabrication, assembly and (opto-) electrical interfacing of nanoscale materials, structures and devices in order to exploit their unique properties within emerging ICT application areas. Tremendous potential for development of new technologies exists through convergence of traditionally disparate disciplines at the nanoscale, e.g., chemical, physical and life sciences and also microelectronic engineering. Special emphasis is placed within the group on development of novel interdisciplinary methods for materials processing, device fabrication and integration. The research is supported by a suite of equipment and laboratory facilities within the group that are amongst the best in Europe.

Compared to traditional macroelectrodes, nanoscale electrodes on silicon chip substrates have tremendous potential when employed in electrochemical based studies; due to enhanced sensitivity arising from increased mass transport to the electrode (convergent, 3D, diffusion) and low background charging currents. Nanoscale electrodes may be employed directly as electrodes in traditional electrochemical methods or in electrogenerated chemical luminescence (ECL) methods. In the latter approach, light is produced following reactions between electrogenerated redox species at an electrode. It is evident that future diagnostic sensor products will require sensing elements that are highly sensitive combined with the ability to detect multiple analytes in parallel. Nanoelectrodes as electrochemical sensors offer a viable route to attaining this requirement. Nanoscale electrodes, when combined with ECL, also offer a new and unexploited detection modality for a wide range of analytes in a variety of application areas including biosensing, chemical and bio-warfare agent detection, and environmental sensing.

State of the art gold nanowires, for use as nanoelectrodes, typically have dimensions on the order of 250 nm in diameter with lengths ranging from 20 60 microns. Recently, we have developed a novel approach for fabricating individual gold nanowires 200 nm (height and width) and up to 900 microns long, which, due to their greatly increased length, should offer an even greater performance enhancement when used as electrochemical sensors. Following fabrication, these nanowires are easily assembled on a silicon chip and electrically contacted. However, key challenges remain to be solved prior to the use of these gold nanowires as sensor elements, e.g., the fabrication of parallel gold nanowire nanoelectrode arrays capable of achieving higher measureable currents (nA mA).

This research project will therefore focus on:
Fabrication and optimisation of parallel arrays of on-chip nanowire electrodes with critical dimensions ranging from 200 nm down to 50 nm.
Validation of the structural properties of nanoelectrode arrays using, nanovisualisation techniques including scanning electron microscopy and atomic force microscopy.
Elucidation and understanding of the interaction mechanisms occurring between analytes and nanoelectrodes by direct electrochemical probing.
Application and characterisation of nanoelectrode arrays as electrochemical and ECL based sensors.

Applications are invited for a funded postgraduate research studentship. The position will lead to a higher degree, Ph.D, and is available to start in January 2009. The successful student will receive training in research methods and will work alongside experienced professional researchers within the nanotechnology group, attend conferences and publish in high impact journals. The minimum academic qualification is a second class honours Bachelors Degree in chemistry, materials science, electronic/electrical engineering, physics or a closely related discipline.

For more information, please contact Alan O'Riordan at alan.oriordan@tyndall.ie

To apply, please submit a CV to careers@tyndall.iequoting the reference number.


To apply for this post, complete the application form and forward with a detailed curriculum vitae and references to:
HR Department
Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland
Fax: +353-21-4904058



Please quote 10 Academic Resources Daily in your application to this opportunity!

If you want to receive academic resources in your e-mail on daily basis, please subscribe to 10resources-subscribe@yahoogroups.com.