Colorimetric Sensors for Chemical and Biological Warfare Agents

We aim to construct litmus paper-like colorimetric sensors for detection and quantification of chemical and biological agents in water by performing combinatorial selection of DNA aptamers for cyanobacteria toxins such as microcystins and saxitoxins. Aptamers are single stranded DNA that can bind target molecules with high affinity and specificity. Such DNA aptamers are biocompatible, biodegradable, and highly stable even at elevated temperatures and dry conditions, especially when conjugated with nanoparticles. Cyanobacteria toxins are the most encountered toxins in water sources. After obtaining toxin-specific aptamers, DNA-functionalized gold nanoparticles will be used to obtain rapid, autonomous, cost-effective and easily interpretable sensors for soldiers in the field. The sensors will be made into a test strip format that can be easily used by soldiers or other users without a chemistry background. Importantly, the same technology will be applicable to detect a broad range of chemical and biological agents without an extensive support system. In the Phase I research, the feasibility of using the proposed approach will be demonstrated and prototype test kits will be constructed and characterized in Phase II.