Transcription factor based whole-cell biosensor for specific and sensitive detection of sodium dodecyl sulfate

Extensive use of Sodium Dodecyl Sulfate (SDS) in households, agricultural operations, and industries is leading to its subsequent disposal in waterways. There is an apprehension of the adverse effect of such detergents on various living organisms. Thus, an efficient, specific, and simple detection method to monitor SDS reliably in the environment is needed. We used sdsB1 activator protein and SDS-responsive promoter of sdsA1 gene along with Green Fluorescent Protein (GFP) to construct a novel SDS biosensor in Pseudomonas aeruginosa chassis. The GFP intensity of the biosensor showed a linear relationship (R² = 0.99) from 0.4 to 62.5 ppm of SDS with a detection limit of 0.1 ppm. This biosensor is highly specific for SDS and has minimal interference from other detergents, metals, and inorganic ions. The biosensor showed a satisfactory and reproducible recovery rate for the detection of SDS in real samples. Overall, this is a low cost, easy-to-use, selective, and reliable biosensor for monitoring SDS in the environment.