Facile synthesis of sub-10 nm Cu-MOF nanofibers as electrochemical sensor element for picomolar chloramphenicol detection

Precise detection of antibiotics in aquatic environments is significant for human health and ecological environment development due to the excessive use of antibiotics. However, the accurate detection of ultralow-level antibiotics, such as picomolar level, has always been an extremely challenging task. Herein, we synthesized the sub-10 nm copper-based metal–organic framework nanofibers (Cu-MOF NFs) with a large specific area and high conductivity for achieving the electrochemical detection of picomolar-level chloramphenicol (CAP) in real water samples. As a result, by optimization of synthesis time and detection conditions, Cu-MOF NFs with a diameter of about 5 nm exhibited the ultralow limit of detection with 0.03 pM and wide detection range with 0.1––1.0 × 106 pM for CAP detection, as well as the designed sensor electrode has the excellent specificity, reproducibility, and stability. Importantly, the prepared sensor electrode exhibits reliable analytical results for CAP in real water samples, such as tap water, bottled water, and milk, indicating that designed sensor electrode has great application potential for the precise detection of antibiotics in practical samples.