Evaluation and Refinement of a Field-Portable Drinking Water Toxicity Sensor Utilizing Electric Cell-Substrate Impedance Sensing and a Fluidic Biochip.

摘要

The US Army's need for a reliable and field-portable drinking water toxicity sensor was the catalyst for the development and evaluation of an electric cell-substrate impedance sensing (ECIS) device. Water testing technologies currently available to soldiers in the field are analyte-specific and have limited capabilities to detect broad-based water toxicity. The ECIS sensor described here uses rainbow trout gill (RTgill-W1) cells seeded on fluidic biochips to measure changes in impedance for the detection of possible chemical contamination of drinking water supplies. Chemicals selected for testing were chosen as representatives of a broad spectrum of toxic industrial compounds. Results of a US Environmental Protection Agency (USEPA)-sponsored evaluation of the field portable device were similar to previously published Army testing results of a laboratory-based version of the same technology. Twelve out of the eighteen chemicals tested following USEPA Technology Testing and Evaluation Program (TTEP) procedures were detected by the ECIS sensor within 1 h at USEPA-derived human lethal concentrations. To further simplify field-testing methods, elimination of a procedural step that acclimated cells to serum-free media streamlined the test process with only a slight loss of chemical sensitivity. For field use, the ECIS sensor will be used in conjunction with an enzyme-based sensor that is responsive to carbamate and organophosphorus pesticides.