DEVELOPMENT OF A CONDUCTIVITY-BASED IMMUNOSENSOR FOR SENSITIVE DETECTION OF METHAMPHETAMINE (STIMULANT DRUG) IN HUMAN URINE

A simple immunosensor based on a conductivity method was developed for determination of methamphetamine (MA, a stimulant drug) in urine. Ant i-MA antibody was immobilized onto the surface of a pair of platinum e lectrodes. The reaction of MA with the antibody causes a decrease in t he conductivity of the anti-MA immobilized layer between the electrode s. A linear relationship was obtained between the conductivity and MA concentration in the range of 1-10 mu g/ml. The method requires the sa mple to be rinsed with water on the electrodes after the immunoreactio n. This detection system was applied to the determination of MA in uri ne and proved to be a useful and a simple detection technique of MA in forensic science in comparison with a gas chromatography-mass spectro metry method. (C) 1996 Published by Elsevier Science Limited.