RUTHENIZED SCREEN-PRINTED CHOLINE OXIDASE-BASED BIOSENSORS FOR MEASUREMENT OF ANTICHOLINESTERASE ACTIVITY

Plastic disposable choline biosensors based on ruthenized-carbon scree n-printed electrodes were prepared and their use for monitoring organo phosphorus pesticides and carbamates is described. The presence of 0.5 % ruthenium on activated carbon mixed to form a simple graphite-based ink for the working electrode surface increased the sensitivity toward s hydrogen peroxide. The choline biosensor is based on such an electro de coupled with choline oxidase immobilized by adsorption and was used to detect the inhibition effect of carbamates and organophosphorus pe sticides on acetylcholinesterase. With the optimized procedure describ ed (pH, buffer composition, incubation time, substrate concentration), concentrations of pesticides (Carbofuran) as low as 1 nM could be det ected.