Organophosphorus and carbamate pesticide analysis using an inhibition tyrosinase organic phase enzyme sensor; comparison by butyrylcholinesterase+choline oxidase opee and application to natural waters

Abstract

Recent research performed in our laboratory (using a butyrylcholinesterase+choline oxidase enzyme electrode) suggested the validity of the biosensor approach using enzyme inhibition OPEEs (i.e. enzyme electrodes working in organic phase) in the case of organophosphorus and carbamate pesticides, which are poorly soluble in aqueous solutions. Since these pesticides are generally much more soluble in chloroform than in water, the present research aimed at analysing this class of pesticides using a tyrosinase inhibition OPEE operating in water-saturated chloroform medium. The tyrosinase biosensor was assembled using an oxygen amperometric transducer coupled to the tyrosinase enzyme, immobilized in kappa-carrageenan gel. Lastly a detailed comparison between the inhibition monoenzymatic tyrosinase and inhibition bienzymatic (butyrylcholinesterase+choline oxidase) OPEEs was performed and discussed in this work.