SBIR Phase I: Biomolecule Immobilization Chemistry for Nanomagnetic/Spintronic Biosensor Array

This Small Business Innovation Research (SBIR) Phase I project is designed to adapt a Giant MagnetoResistive (GMR) sensor device into a "spintronic" multianalyte biosensor. The potential value of biosensor technology is being recognized for a wide range of applications, from medical diagnostics to countering bio-terrorism. Magnetic nano/microparticles present advantages as labels for biomolecule binding, including stability and low background signal. This project will provide improved biomolecule coupling technology for biosensor applications of certain GMR microelectrode array and the paramagnetic microbeads under development. The Phase I effort will include the synthesis and use testing of photochemical and electrochemical polymer derivatives for binding oligonucleotides to the silicon nitride surface of GMR electrodes and to uncoated NiFe microparticles. Biomolecule binding activity, stability, and signal/noise properties will be measured by fluorescent and magnetic assay methods and shown to be equal or superior to those of currently used assays. These Phase I results are expected to provide a solid technical background for optimizing the biomolecule immobilization chemistry in Phase II, as well as new but related latent-reactive polymers for enhanced microfluidic channel coating and lid adhesion for the GMR biosensor flow cell. Commercially coating reagents and procedures for specific biomolecule binding on microelectrode arrays and on paramagnetic metal nano/microparticles are expected to command a significant fraction of the greater than $5 billion genomic and proteomic assay disposables market expected by 2010. They have the capacity to give greatly lowered cost and enhanced ease of use for consumers in the military, personal care, and security fields. The coatings will help enable a lab-on-a-chip sensor that can be used in the field to give accurate and timely readouts on biohazards, potentially saving people's lives. Additionally, the development of a new general coating technology for magnetic materials will have impacts beyond biosensors, including ferrofluids, magnetic memory devices, and many others.