STTR Phase I: Novel Colorimetric Amplification Technology

This Small Business Technology Transfer (STTR) Phase I project has the potential to improve health and safety of individuals in society. The ability to detect harmful substances and disease is critical to human health and safety. Multiple detection technologies are currently used to detect harmful substances and disease. Colorimetric methods are preferred for field detection because they are low-cost, easy-to-use, and field-rugged; however, their utilization is limited by a lack of sensitivity. While more complex detection technologies have excellent sensitivity, their field usefulness is limited by their high cost, complexity of use, and fragility. The proposed innovation enables amplification of colorimetric detection, thereby improving the perceived sensitivity of the technology. As a result, the proposed innovation has the potential to enable new low-cost devices that detect harmful substances and disease. The results of this effort will also provide further insight into the understanding of both fundamental and applied aspects of nanostructured materials. This multi-disciplinary effort involves transformative research which will further the integration of composite materials into real-world sensor applications. The intellectual merit of this project is the demonstration of a color amplification strategy which would improve the detection limits of any colorimetric chemistry by one to three orders of magnitude. The main objective of this effort is to demonstrate colorimetric response amplification via the use of synergistic composite materials from nanomaterials and colorimetric thin film sensors. Methods to be employed include thin-film deposition and electron beam lithography for the production of nanostructured materials. A composite approach involving nanomaterials and thin-film coatings potentially offers significantly enhanced colorimetric sensing capabilities through color amplification. The intrinsic absorption efficiency of a colorimetric indicator defines the maximum potential performance of that indicator in a passive sensor. The proposed innovation aims to artificially increase the absorption efficiency of colorimetric indicators, and thus render sensors made from these materials significantly more sensitive to chemical analytes of interest. Nanomaterial-functionalized flexible substrates will be designed and fabricated, on which thin-film colorimetric sensing coatings will be deposited. The colorimetric response of these thin-film composite sensors will be evaluated as a function of exposure to chlorine gas. Colorimetric response enhancements will be assessed based on spectroscopic reflectance data.