Enzyme Based Test Stripes for the Visual or Photographic Detection and Quantitation of Gaseous Sulfur Mustard
Bidmanova, S., Steiner, M.S., Stepan, M., Vymazalova, K., Gruber, M.A., Duerkop, A., Damborsky, J., Prokop, Z., Wolfbeis, O.S.
ANALYTICAL CHEMISTRY 88: 6044-6049 (2016)
Sulfur mustard is a chemical agent of high military and terroristic significance. No effective antidote does exist, and sulfur mustard can be fairly easily produced in large quantity. Rapid field testing of sulfur mustard is highly desirable. Existing analytical devices for its detection are available but can suffer from low selectivity, laborious sample preparation, and/or the need for complex instrumentation. We describe a new kind of test stripe for rapid detection of gaseous sulfur mustard that is based on its degradation by the enzyme haloalkane dehalogenase that is accompanied by a change of local pH. This change can be detected using pH indicators contained in the stripes whose color changes from blue-green to yellow within 10 min. In addition to visual read-out, we also demonstrate quantitative reflectometric readout by using a conventional digital camera based on red-green-blue data acquisition. Organic haloalkanes, such as 1,2-dichloroethane, have a negligible interfering effect. The visual limit of detection is 20 µg/L, and the one for red-green-blue read-out is as low as 3 µg/L. The assays have good reproducibility +/- 6 % and +/- 2 % for inter-day assays and intra-day assays, respectively. The stripes can be stored for at least 6 months without loss of function. They are disposable and can be produced fairly rapidly and at low costs. Hence, they represent a promising tool for in-field detection of sulfur mustard.