Fluorescent Silicate Materials for the Detection of Paraoxon

Porphyrins are a family of highly conjugated molecules that strongly absorb visible light and fluoresce intensely. These molecules are sensitive to changes in their immediate environment and have been widely described for optical detection applications. Surfactant-templated organosilicate materials have been described for the semi-selective adsorption of small molecule contaminants. These structures offer high surface areas and large pore volumes within an organized framework. The organic bridging groups in the materials can be altered to provide varied binding characteristics. This effort seeks to utilize the tunable binding selectivity, high surface area, and low materials density of these highly ordered pore networks and to combine them with the unique spectrophotometric properties of porphyrins. In the porphyrin-embedded materials (PEMs), the organosilicate scaffold stabilizes the porphyrin and facilitates optimal orientation of porphyrin and target. The materials can be stored under ambient conditions and offer exceptional shelf-life. Here, we report on the design of PEMs with specificity for organophosphates and compounds of similar structure. Published in Sensors, v10 p2315-2331, 2010. Performed in collaboration with NOVA Research Incorporated, Alexandria, VA. Naval Research Laboratory work unit no. 69-8765. Sponsored in part by the Defense Threat Reduction Agency (DTRA; BA08PRO015) and the Department of Defense Strategic Environmental Research and Development Program (SERDP; ER-1604).