(603e) A MEMS-Based Toxicity Sensor Using An Acetylcholinesterase Mimic

Toxicity is defined as the degree a substance can damage an organism. Portable devices to screen for toxic compounds are needed for environmental, medical, pharmaceutical, and military applications. Previous work has concentrated on a variety of biological and chemical methods in order to measure toxicity in vitro. The short lifetime of biological methods and the lack of selectivity of chemical methods, however, make them poor candidates for portable toxicity detection. Biological mimics, on the other hand, provide the selectivity of a biomolecule with the stability of a chemical compound. Here we report a MEMS-based toxicity sensor that utilizes oxime, a cholinesterase mimic, in order to selectively detect acetylcholinesterase inhibitors. The selective detection mechanism of this toxicity sensor allows for the identification of acetylcholinesterase inhibitors without the use of an unstable enzyme. We found that there is a good linear relationship between sensor response and a compound's LD50, allowing the device to be used to measure toxicity of unknown compounds or mixtures. Our results demonstrate how biological mimics can be used to imitate toxicological modes. We anticipate our assay to be a starting point for the development of more toxicity sensors based on biological mimicry. For example, mimic systems could be developed for other toxic modes of action, including oxidative stress and phosphorylation inhibitors. We expect this type of sensor to be of great practical importance for screening new pharmaceuticals, foodstuffs, water, etc.