Graphdiyne chelated iron-based metal–organic frameworks for electrochemical sensing of antibiotic chloramphenicol with ultralow detection limit

Chloramphenicol (CAP), a broad-spectrum antibiotic agent that can inhibit protein synthesis, has caused environmental and human health problems upon excessive usage but to realize its ultrasensitive detection is still a great challenge. We report here the design and fabrication of a nanocomposite comprising graphdiyne (GDY) chelated iron-based metal–organic framework (Fe-MOF@GDY) with strong interfacial interaction to achieve high performance electrochemical sensing of CAP. Fe-MOF@GDY exhibits good selectivity, a linear range of 1 pM−24 mM and an ultralow detection limit down to 0.54 pM, among the best performance for CAP detection. It displays good reproducibility and storage stability with retained 98.4% of its initial response after 3 weeks. GDY with unique electronic structure enhances charge transfer of Fe-MOF for improved conductivity, and Fe-MOF nanoparticles are uniformly chelated on GDY for rich active sites towards CAP reduction. Fe-MOF also prevents GDY from being degraded, promoting long-term stability. A portable electrochemical chip is fabricated based on Fe-MOF@GDY, and is successfully used for accurate detection of CAP in lake water with recovery rates of 97.2–104.7%, demonstrating the practical on-site applications.