Santa Clara University

Dr.  Marcin Majda, from Bioanalytical Chemistry and Electrochemistry at UC Berkeley, will speak on "Antibody-Antigen Exchange Equilibria in a Field of an External Force: Design of Reagentless Biosensors"

Friday, October 16, 2009, 4 - 5 pm

Alumni Science 120

ABSTRACT:

This seminar concerns a new strategy for detecting biological moledules that relies on competitive exchange interactions of an analyte with two-component molecular tethers attaching superparamagnetic microspheres (4 microns in diameter) to a sensor surface.  The individual tethers consist of an antibody-antigen complex and are designed to selectively detect antigenic proteins in a sensitive reagentless fashion.  In order to impart a driving force to the otherwise free energy neutral antibody antigen exchange equilibrium, a small mechanical force of ca. 10 pN was applied to stretch the antibody-antigen tethers using a massively parallel magnetic tweezers device.  The experimental work was carried out with human cardiac troponin I.  This serum heart attack marker was used as an example of analytes of a credible relevance to biomedical diagnostics.  The initial results illustrate the functioning of a cardiotroponin sensor and offer a preliminary estimate of its sensitivity of 16 pM.

Dr. Majda will be in Daly Science 103 from 3:15 - 3:50 pm to meet with students