Fiber-Optic Probe Uses Evanescent Waves To Sense Biofilm

A compact instrument includes a fiber-optic probe that utilizes the evanescent-wave interaction to measure the accumulation of a biofilm. This instrument is a prototype of instruments that could be used to effect continuous monitoring and provide early warning of biofilms associated with bacterial contamination in diverse water systems, including potable-water supply systems, industrial heat-exchanger systems, and heating and cooling systems for buildings. The instrument makes it possible to detect biofouling of such systems sooner than the ends of the 24-to-48 hour incubation periods needed for conventional detection of bacteria by culture-plate counting.