Biosensor based on electrospun blended chitosan-poly (vinyl alcohol) nanofibrous enzymatically sensitized membranes for pirimiphos-methyl detection in olive oil

An ultra-sensitive electrochemical biosensor was successfully developed for rapid detection of pirimiphos-methyl in olive oil, based of genetically-engineered acetylcholinesterase (AChE) immobilization into electrospun chitosan/poly (vinyl alcohol) blend nanofibers. Due to their unique properties such as spatial structure, high porosity, and large surface area, the use of nanofibers allowed improving the biosensor response by two folds. The developed biosensor showed a good performance for detecting pirimiphos-methyl, with a limit of detection of 0.2 nM, a concentration much lower than the maximum residue limit allowed set by international regulations (164 nM). The biosensor was used for the detection of pirimiphos-methyl in olive oil samples after a simple liquid-liquid extraction, and the recovery rates were close to 100%.