The Huck Institutes of the Life Sciences

Label-free detection of biochemical interactions using vibrational and Kelvin fields

Mike Thompson (University of Toronto, Canada)

When: Tuesday, May 6, 2008 - 2:30pm - May 6, 2008 - 3:30pm
Where: 100 Life Sciences Building/Berg Auditorium
Name: Srinivas Tadigadapa

If you would like to schedule a meeting with Prof. Thompson on May 6 or May 7, please contact Srinivas Tadigadapa (


Use of tagging agents involving radiochemicals or fluorescent ligands is common in bioanalytical chemistry. Our work is concerned with efforts to avoid the use of such species through the direct detection of the chemistry of proteins, nucleic acids and cells at a device surface. We use the conventional thickness shear mode acoustic wave device in a flow injection mode to examine protein conformation and neuron interactions with drugs at a gold surface. This work has been extended recently to ultra high frequency acoustic wave detection of immunochemistry on a quartz surface. Frequencies of over 1 GHz are instigated through electromagnetic fields generated by a flat spiral coil. The particular application is the detection of HIV antibody in serum. This project also involves new strategies for the attachment of peptide probes to surfaces that avoid the vexing biosensor-non-specific adsorption problem.

With respect to the Kelvin field, we have developed an instrument that is capable of the measurement of substrate work function with a spatial resolution of 100 nm. This is being employed in both scanning and single detection modes with applications being focused on protein microarrays and sensing of cell behavior. In terms of the latter we have examined N-38 neurons and the effect ts caused by neurotrophic factors.