Screen-printed acetylcholinesterase-based biosensors for inhibitive determination of permethrin

An amperometric assay based on acetylcholinesterase (AChE) inactivation has been developed for the monitoring of permethrin using a screen-printed three-electrode system. The enzyme AChE catalyzes the hydrolysis of acetylthiocholine to thiocholine, which can be electrochemically oxidized. The presence of permethrin inhibits the AChE activity, resulting in a lower thiocholine production and thus, a decrease in the amperometric oxidation current. Immobilization of AChE was performed by cross-linking giving a capability of detection of 8.1 ± 0.4 μM. Repeatability and reproducibility of the developed AChE biosensor were also calculated, yielding values of 9.6% (n = 4) and 5.4% (n = 5), respectively related to the slopes of the calibration curves performed in the range from 6.2 up to 41 μM. The method was successfully applied to the determination of permethrin content in a commercial lice gel.

► Environmental friendly amperometric determination of permethrin on AChE based biosensors using SPEs
► High degree of selectivity and sensibility in the analysis of permethrin
► Application of the method to the quantitative analysis of permethrin even in complex samples, such as a lice gel