Fmoc-Phe-oPDA/Zr-MOF Coated Carbon Fiber for Electrochemical Detection of Chloramphenicol and Furazolidone Residues in Food Samples

Zr-based metal–organic frameworks (Zr-MOFs) hybridized with carbon fiber materials have emerged as effective platforms for advanced electrochemical interfaces due to their high surface area and favorable charge-transfer property. In this work, Fmoc-Phe-oPDA (FPP) was synthesized and systematically characterized using mass spectrometry, 1 H NMR, XRD, SEM, and FTIR spectroscopy. The prepared FPP was hybridized with Zr-MOF and carbon fiber to prepare a Fmoc-Phe-oPDA@Zr-MOF/CF modified glassy carbon electrode (FPP@Zr-MOF/CF/GCE). The FPP@Zr-MOF/CF/GCE electrode exhibited enhanced electrocatalytic activity toward chloramphenicol (CAP) and furazolidone (FZ), attributed to the synergistic interaction between the porous Zr-MOF architecture, peptide functionality, and conductive carbon fiber network. Electrochemical studies revealed high sensitivities of 1.0 μA μM −1 cm −2 for both CAP and FZ, with detection limits of 4.5 μM and 0.56 μM, respectively. The simultaneous detection of CAP and FZ exhibited excellent repeatability, stability, reproducibility, and selectivity against potential interfering species. Furthermore, the applicability of the developed electrode was validated through the successful determination of CAP and FZ in real food samples, yielding satisfactory recoveries. The results highlight the effectiveness of FPP@Zr-MOF/CF as a robust electrochemical interface, providing insights into the rational design of peptide–MOF–carbon-based electrocatalytic systems for analytical and sensing applications.