(347i) Gas Phase Organophosphorus Detection Via Encapsulation of Enzyme Into Peptide-Nanotubes

Gas Phase Organophosphorus Detection via Encapsulation of Enzyme into Peptide-Nanotubes

Eric B. McDaniel, Dong-Shik Kim, Mark N. Goltz*

Department of Chemical and Environmental Engineering, The University of Toledo, Toledo OH 43606

*Air Force Institute of Technology, Wright Patterson AFB OH

Abstract

Organophoshporus (OP) compounds are commonly used for various aggressive functions such as pesticides as well as nerve agents. These compounds are being used in the environment for crops and domestic use, and it is imperative to detect and remove these compounds to assure safety to humans as well as the environment. In this research, the goal is to develop an easy-to-make biosensor to detect these OP pesticides. By doing such, the sensors are prepared with enzyme-encapsulated Peptide Nanotubes (PNTs) that is made from diphenylalanine. PNTs can be formed by self-assembly, and are easily prepared. From other research, PNTs have been found to help preserve the enzyme activity. Organophosphorus Hydrolase (OPH), an enzyme that has been used to detect Organophosphates, is used in this research as the enzyme to detect malathion. Malathion is a common OP pesticide that is mildly toxic as compared to its sibling OPs. Thus, using OPH gives a direct method of detecting malathion. These sensors are tested in liquid phase of malathion, using cyclovoltametry (CV) as the method of detection. The detection tests gives us the relationship that as the concentration of malathion increases, the increase of CV peak from the blank CV peak becomes larger. Thus this graph shows promising results that give a linear relationship of average percent increase of peak versus concentration. Enzyme activity tests of OPH that has been encapsulated into PNTs shows significant increase in longevity as compared to non-encapsulated OPH.