Combining Electrochemistry and Biology to Create a Suite of Portable Biosensors for Water Analysis

Water analysis is a complex process requiring sample preparation, shipping, and analytical machinery. Often this process is removed from the individuals who require the test results. FREDsense Technologies is developing a platform sensor system for the fast and efficient analysis of water chemistry using biosensors. By combining biology and electrochemistry, microbes can be utilized to specifically measure a variety of different chemical compounds. FREDsense has demonstrated the efficacy of the platform through the development of an arsenic sensor (FRED-As) and FREDsense aims to commercialize and launch this product for near real-time arsenic analysis in the field. The FRED system works through genetically engineering bacteria such that when they encounter a contaminant of interest they cleave a substrate in proportion to the target compound to produce a redox active species. This species then diffuses to a screen-printed carbon electrode surface to undergo a reversible oxidation detected either via cyclic or square wave voltammetry. This use of bacteria as an intermediary in the detection of compounds of interest creates a large signal amplification, as trace quantities of pollutants (low ppb) can be translated into the production of currents that are easily detectable on an inexpensive handheld potentiostat system (< $100). To date, this system has been shown to respond reliably to single ppb levels of As (III) in under an hour in a laboratory setting, with field trials currently underway in multiple locations. This is coupled with an inexpensive and easy to manufacture potentiostat system running open-source software. This system is also expandable to detect other contaminants through the implementation of different genetic circuits, producing a selection of bacteria that can be chosen to monitor the varied needs of unique testing locations. Combined, this creates a powerful platform technology that can simplify the water analysis process for a variety of industries.