THE AMPEROMETRIC BIOSENSOR FOR DETECTION OF SODIUM DODECYL-SULFATE

A Pseudomonas rathonis T-based amperometric biosensor was constructed for detection of anionic surfactants. Microorganisms contained the pla smid for surfactant degradation. The sensor was highly sensitive to so dium dodecyl sulfate (SDS) and volgonat. The lower limit of SDS detect ion was within a range of 0.25-0.75 mg l(-1). The measurement time did not exceed 5 min. 25 substances (hydrocarbons, polyols, alcohols, aro matic xenobiotics) were used to determine the substrate specificity. T he sensor had the highest sensitivity to SDS; the responses to other d etergents - volgonat, decylbenzene sulfonate, metaupon, toluene sulfon ate and alkylbenzene sulfonate - were 82, 36, 20, 10 and 10% of respon se to SDS, respectively. The sensor also reacted to ethanol (56% of re sponse to SDS), glucose (6% of response to SDS) and acetate (28% of re sponse to SDS). The optimal laboratory conditions for SDS detection ar e 30 mM phosphate buffer, pH 7.5, temperature 20 degrees C.