A biosensor as warning device for the detection of cyanide, chlorophenols, atrazine and carbamate pesticides

The determination of cyanide, chlorophenols, atrazine, dithiocarbamate and carbamate pesticides is described, utilizing an amperometric biosensor constructed by the electropolymerization of a pyrrole amphiphilic monomer-tyrosinase coating. Measurements were carried out with catechol, dopamine, l-DOPA or epinephrine as an enzyme substrate; the enzymatically generated quinoid products being electroreduced at -200 mV vs. SCE. The detection of these water pollutants was performed via their inhibiting action on the tyrosinase electrode. The characterization of the inhibition processes (competitive /non-competitive) and their reversibility were examined. The detection limits are 0.4, 2, 2, 4 and 0.02 μM for 3,4-dichlorophenol, chloroisopropylphenylcarbamate, 3-chloroaniline, atrazine and cyanide, respectively.