Novel zirconium-based supramolecular organic frameworks/fullerene@strontium-based MOFs composite for highly sensitive...

A novel ternary composite of zirconium-based supramolecular organic framework/fullerene@strontium-based metal-organic framework (Zr-SOF/C₆₀@Sr-MOF) was synthesized and adopted as an electrode modifier to construct a high-sensitivity electrochemical sensor for ciprofloxacin (CIP) determination. The composition and morphology of the material were confirmed by SEM, TEM, XPS, XRD and FT-IR. Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to evaluate the electron-transfer properties and interfacial behavior of the modified electrodes, and square wave voltammetry (SWV) was employed for the sensitive and quantitative detection of the target analyte. The results reveal that the composite inherits the abundant porous structure of Zr-SOF, the expansive specific surface area of Sr-MOF and excellent electron transfer capability of fullerene. The sensor enables accurate CIP detection in the linear range 5.0 nM-1000 µM, with a detection limit of 7.0 nM (S/N = 3), along with satisfactory selectivity, reproducibility and long-term stability. Practical application was validated in lake water, tap water and milk samples, yielding recoveries of 95.3%-101.63%. This work provides new insights into SOF/MOF-based electrochemical sensing and establishes an efficient strategy for rapid on-site detection of CIP antibiotics in environmental and food matrices.