Sensitive and rapid electrochemical detection of nitroaromatic pesticides by the ordered macro-microporous ZIF-8 immobilized lipase-based sensor

The high toxicity and bioaccumulation effects of nitroaromatic pesticides and their serious environmental risks have led to a sharp increase in public concern about pesticide residues. Present work developed a direct, rapid, sensitive and reliable Candida rugosa lipase (CRL)@ the ordered macro-microporous ZIF-8 (MAC-ZIF-8) nanofibers biosensor (CRL@MAC-ZIF-8 nanofibers) for methyl parathion and chlornitrofen residues detection in lake water. The biosensors fabricated by the CRL@MAC-ZIF-8 nanofibers demonstrated wide linear range for both methyl parathion (0.5–114 µM) and chlornitrofen (1–40 µM) detection. The biosensors also demonstrated good reusability for methyl parathion detection with retainment of more than 97% of its initial response after scanning continuously for 100 times. During 1 month storage stability test at 4 °C, the fabricated biosensor demonstrated excellent stability for methyl parathion detection with retainment of 86%-100% of its initial response. Meanwhile, the biosensors also demonstrated good recovery rates when the biosensors were used to detect methyl parathion and chlornitrofen residues in lake water sample.