Ultra-sensitive water contaminant detection with transcription factor interfaced microcantilevers

Abstract

Water contamination is a growing global concern, creating a need to develop technologies that can detect a range of target compounds at the required thresholds. Here, we address this need by merging biological allosteric transcription factors with DNA coated nanomechanical microcantilevers to detect chemicals in water with digital readout. After proof-of-concept demonstration and optimization to detect tetracycline with the TetR transcription factor, we use the CadC transcription factor to detect Pb2+ and Cd2+ in water at concentrations down to 2 ppb and 1 ppb, respectively, in less than fifteen minutes. A computational model suggests this improvement in sensitivity could be achieved by the DNA coated microcantilever surface changing transcription factor binding properties. Our findings demonstrate a promising new approach for water quality monitoring with fast, highly sensitive, digital readouts.