Note: The information shown here will always lag behind my current results, since I will only show published information.

I work and research at the Laboratory for Biosensors & Bioelectronics at the ETH Zürich (Eidgenössische Technische Hochshule or The Swiss Federal Institure of Technology in English). The LBB was created in July 2006 and I joined at the beginning of November 2006. Although I didn't witness the physical construction of the lab, it has been great to have been involved in the construction of the personal and social atmopshere in our group.

My please click on the link to visit my official research page at the LBB. This might provide you with a more accurate and current description of my research and its progress. Here is the one-page summary of my project, which I first read in June 2006. My interview followed soon thereafter in July 2006: Nanowire Biosensing (PDF). It will be interesting to see how my project grows and evolves compared to the initial thoughts and assumptions from this project summary.

The main goal of my project is to explore various methods of constructing nanowires and from them, to construct biosensors and/or new types of electronic systems (i.e. bioelectronics).

Nanowires, as the term implies, are objects with a diameter in the nanometer scale (i.e. 10-9 m), which are able to conduct electricity. As a wire decreases in diameter to the nanometer regime, the ratio of surface atoms compared to interior atoms, i.e. the surface-to-volume ratio, drastically increases. Therefore, external influences by charged particles or biological species increasingly influence the conduction both on the wire surface and in the wire interior. This concept is illustrated in Figure 2. This is one reason why nanowires become interesting for biosensing. If we monitor current through such a wire and if something comes into contact with the surface of the wire, the current will change.

 

 

• DNA-Assisted Pattern Reproduction

• Simulation of Electrical Properties in Particle-Based Nanostructures

• Nanoparticle & Nanotube Functionalization

Figure 2 - An illustration to demonstrate the concept of the influence of surface interactions on nanowire conduction. In larger wires, for example with micrometer dimensions, the surface-to-volume ratio is relatively small. Even if surface interactions, such as binding with charge particles or biological species, influence conduction near the surface of the wire, there is still a large portion of the wire’s interior available for uninterrupted conduction. To help visualize this, the illustration uses a mental construct of 'conduction channels' within the wire. As the dimensions of a wire decrease to the nanometer regime, the surface-to-volume ratio drastically increases. Therefore, the same external influences increasingly influence the conduction both on the wire surface and in the wire interior, thereby decreasing the possibility for uninterrupted conduction.

Figure 3 -

Large area arrays of metal nanowires
Auzelyte, V.; Solak, H.H.; Ekinci, Y.; MacKenzie, R.; Voros, J.; Olliges, S.; Spolenak, R.; Microelectronic Engineering, 85(5-6), 1131-1134, 2008

Enzymatic Biosensors - Principles and Applications
R. MacKenzie, D. Grieshaber, J. Vörös, and E. Reimhult; Sensors, 8(3); 1400-1458, 2008.