(606a) Optical Enzymatic Biosensor for Sensitive Detection of 1,2,3-Trichloropropane

The emerging water contaminant 1,2,3-trichloropropane (TCP; also known as allyl trichloride, glycerol trichlorohydrin, and trichlorohydrin) is used as an industrial solvent, as a cleaning and degreasing agent, and in the production of pesticides.  TCP is a known toxin and has been determined by the State of California to cause cancer.  The State of Hawaii has established a state MCL of 0.6 μg/L, and the California Department of Public Health has established a notification level of 0.005 μg/L.  A significant need exists for devices that can measure the concentration of TCP and other chemical contaminants in ground and surface waters, and in the influent and effluent streams of water remediation and treatment facilities.  These measurements must be rapid, accurate, and inexpensive.  Although laboratory-based methods relying on chromatography can yield very accurate measurements, they are also complex, time consuming, require sample pre-treatment, and expensive.  Furthermore, they are not readily adapted for in-situ measurements.  In contrast, biosensors can provide simple, rapid, in situ, inexpensive measurements that do not require pretreatment of the sample. 

We have developed optical enzymatic biosensors for the sensitive measurement of TCP concentrations in aqueous solutions.  In our biosensors, a two-layer detection element – one layer containing the detection enzyme affixed to another fluorophor-containing layer – immobilized on the distal end of an optical fiber, which is connected to a light source/detection unit.  The change in fluorescence depends on the contaminant concentration, and these sensors provide quantitative output over a range of analyte concentration.  Performance metrics including the limit of detection, impact of environmental factors such as pH and temperature, and lifetime have been determined.