Electrochemical sensor for ultrasensitive detection of paraquat based on metal-organic frameworks and para-sulfonatocalix[4]arene-AuNPs composite

The widespread occurrence of pesticides in surface water, groundwater, soil, and food has received increasing attention towards environmental safety. Paraquat (PQ) is world widely used as a rapid sterilant herbicide and is highly toxic to humans. A simple, rapid, sensitive, and on-site detection method for the water environment to detection of PQ is urgently required. Here, we prepared a zeolite imidazole skeleton-8 (ZIF-8) and para-sulfonylcalix[4]arene (pSC4) coated gold nanoparticles composite (pSC4-AuNPs@ZIF-8) by one-step method. An electrochemical biosensor assay for PQ was established based on pSC4-AuNPs@ZIF-8 modified glassy carbon electrode through host-guest recognition of PQ and pSC4. Under the optimal conditions, recoveries of targets determination results were 92.7%-103% (n = 3), respectively. The quantity PQ detection limit was found to be 0.49 pM. Therefore, the signal amplification strategy based on pSC4-AuNPs@ZIF-8 has potential value in detecting trace pollutants in the water environment.