Biosensor based on multi-walled carbon nanotubes paste electrode modified with laccase for pirimicarb pesticide quantification

► Composite carbon paste/laccase-based biosensor was developed to quantify pirimicarb. ► Four-aminophenol was used as mediator of electron transfer. ► Pirimicarb analytical data was obtained by inhibition of the enzymatic catalysis. ► The biosensor exhibited linearity in a range of 9.90×10−7 to 1.15×10−5 mol L−1. ► The enzymatic biosensor was successfully applied to vegetable crops.