Developing a Small-Molecule Immunoassay

University Of Utah, Salt Lake City UT

Investigators

Abstract

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Conboy at the University of Utah is developing new analytical methods for small-molecule (low molecular weight substances) detection and quantification. Antibodies, with their chemical specificity and high affinity are exceptionally suited for bio-specific detection and quantification. However, utilizing antibodies for the direct label-free detection of low molecular weight substances is a major technical challenge. Professor Conboy is using nonlinear optical methods to develop a highly sensitive small-molecule immunoassay, providing a reliable, label-free method for detecting and quantifying low molecular weight substances. The research outcome is to provide a set of new highly sensitive analytical tools for the purpose of detection of illicit substances and hazardous substances screening. Integrated within the research objectives is the education of both graduate and undergraduate students in analytical/bioanalytical chemistry, which is of great National importance in maintaining the strength of the US economy and the competitive edge of US biotechnology industries. Professor Conboy is also involved in hands on demonstrations, science fair activities and assistance with setting up dedicated teaching space for science experiments at local primary schools in the Salt Lake valley with the goal of exposing primary grade students to the wonders of the chemical world and to promote teacher training and introducing young people to the potentials of science. The scientific goal of the proposed studies is to implement second-harmonic correlation spectroscopy (SHCS) for rapid single point calibration and utilize the high-throughput capabilities of second harmonic imaging (SHI) for screening and quantification. These complimentary techniques, SHCS and SHI have many inherent advantages over existing approaches. SHCS has the intrinsic advantage that calibration (binding affinity data) can be obtained from a single concentration of the analyte to derive the Kd (or Ka) in a fraction of the time required by a conventional thermodynamic equilibrium binding isotherm measurement, with the added benefit of acquiring both the association and dissociation rates. SHI has the advantage of high-throughput measurement by utilizing antibody capture arrays. Both methods are also biologically versatile and capable of detecting any molecule containing conjugated structures, including virtually all biomolecules targeted in current assays. Together these methods represent a unique analytical approach that does not compromise sensitivity and speed yet provides a novel, cost effective, and flexible immunoassay format.