*** 9661439 Guire This project is designed to demonstrate the feasibility of a generally applicable, facile, and cost-effective approach to coating of plastic materials used in specific binding assay and biosensor systems. Covalent passivation of the surface with a biomolecule-compatible stabilizing agent, patterned immobilization of biomolecules, which are critical and enduring obstacles to the commercial development of biosensor technology, will be resolved through the preparation of a photoreactive "universal binding" thin film surface. Covalent photochemical bonding of the high affinity general ligand (biotin) derivative and of the passivating/stabilizing agent, will be accomplished quickly under mild reaction conditions by patterned and uniform illumination, respectively. A patterned array of X-avidin immobilized on passivated optical grade plastic will be obtained by dip-coating this surface with a crude or purified solution of this multi-site binding protein, then prepared for multianalyte assay use with essentially any nucleic acid probes or specific analyte binding proteins (e.g., antibodies) assay through differential loading of the individual assay dots of the array by inkjet printing (e.g., with the desired biotinylated oligonucleotides for cystic fibrosis gene defects). This approach is expected to provide cost-effective solutions to the outstanding technical problems of the biomolecule-sensor interface of small sample, sensitive , multiananyte, rugged portable commercial devices under development for nucleic acid probe and immune assays of value for environmental, food, infectious disease, and gene sequence analysis and monitoring. ***