This Small Business Innovation Research Phase I project will evaluate the feasibility of CD (compact disc) detection of surface-based multiplex biological assays as a viable commercial alternative to fluorescent detection. The feasibility study will include two components: 1) the biochemical functionalization of the surface of the polycarbonate material that CDs are composed of, using a novel, plasma-based process, and 2) the development of requisite software programming steps to allow a CD-ROM drive to read a CD-based multiplex assay. Multiplex assays based on surface-based microarrays of biological molecules have become an important tool in biological research. The potential of microarrays is limited by reliance on fluorescence as a method of detection, because fluorescent labeling of most biomolecules is difficult or not possible. A potential alternative is the label-free quantitative detection of molecular interactions on the<br/>surface of a CD, inserted into the CD-ROM drive for readout. <br/><br/>Label-free multiplex bioassays using the surface of a CD have significant commercial potential and will also enable scientific advances. Off-the-shelf CD-ROM drives, costing as little as 50 cents and available in all modern personal computers, can be converted into scanners using appropriate software. A laptop computer with a built-in CD-ROM drive is highly portable and can act as a workstation for field biological measurements. High-throughput screening for drug development will yield more reliable results without<br/>fluorescent tagging.