Direct, selective and ultrasensitive electrochemical biosensing of methyl parathion in vegetables using Burkholderia cepacia lipase@MOF nanofibers-based biosensor.

Methyl parathion is one of the most widely used pesticides in agricultural practices. It caused accumulation of acetylcholine and over-stimulation of receptors in synapses which eventually led to damage of the nervous system. Present study developed a direct, sensitive, rapid and reliable method for methyl parathion residues detection in vegetable samples. MOF nanofibers which demonstrated stable framework structure, good thermal/chemical stability, good electrochemical behavior, high porosity, surface area and pore volume was synthesized and used for fabrication of Burkholderia cepacia lipase (BCL)@MOF nanofibers biosensors. BCL@MOF nanofibers/chitosan/GCE biosensor demonstrated high sensitivity for methyl detection with a wide linear range (0.1-38 µM) and low limit of detection 0.067 µM. During the 3 weeks storage stability test at 4 °C, the fabricated biosensor demonstrated good reusability and excellent stability for methyl parathion detection with retainment of more than 80% of its initial response. When applied for detection of methyl parathion residues in vegetable samples, the BCL@MOF nanofibers/chitosan/GCE biosensors demonstrated good recovery rates.