Document Type


Presentation Date



Chemical and Paper Engineering


Most quantitative immunodiagnostic assay products require large laboratory equipment, controlled lab environments, and highly skilled technicians, making them expensive and impractical for use in other environments such as physician offices, the home and field clinics of developing countries. The long-range goal of this work is to attempt to develop an inexpensive quantitative hand-held immunobiosensor-based technology that can easily be applied to any antibody:antigen combination and used in any setting. A new approach to measure antibody:antigen binding in the presence of nanotubes has been described in several recent studies. Using conductive polymer/nanotube/antibody solution-impregnated filter paper, these researchers showed a change in filter paper conductivity (resistance) upon application of the antigen-containing sample (1, 2). This change, measured as a chemical potential change in the test strip, was hypothesized to be due to antigen binding to the impregnated antibody that altered the electrical contact between adjacent conductive nanotubes. In contrast to these studies using imprecisely-loaded filter paper test strips, our work aims to develop and evaluate an immunoresistive biosensor comprised of a precisely formulated thin film composite antibody:nanotube micro-expandable matrix mesh-like conductive material (“matrix”). This matrix is coated and then cured between two electrical contacts printed on flexible non-porous film. Initial experiments to demonstrate proof of concept of our design resulted in improvements in both the design of the test system components and in the formulation of the matrix. In this study, a test system and sensor design is described which performs with the accuracy necessary to enable fine-tuning of matrix formulations to prove the concept. Test results of the latest formulation and future directions are discussed.

Available for download on Monday, April 15, 2024