MgO/NiCoFe2O4 modified electrochemical sensor for simultaneous detection of ascorbic acid and levofloxacin

Abstract

The current study aimed to synthesize and characterize magnesium oxide–bimetallic nickel cobalt ferrite nanohybrid (MgO/NiCoFe₂O₄-NH) for its application in the simultaneous electrochemical detection of ascorbic acid (AA) and levofloxacin (LEV). The NiCoFe₂O₄-NPs were synthesized using the sol–gel green method and fabricated with MgO. The synthesized materials were characterized using advanced analytical techniques. XRD confirmed single-phase spinel and cubic structures of NiCoFe₂O₄-NPs and MgO/NiCoFe₂O₄-NH with an average crystallite size of 6.5 nm and 11.4 nm, respectively. SEM and AFM revealed spherical/semi-spherical morphologies and extremely rough surfaces of MgO/NiCoFe₂O₄-NH, respectively. The average zeta potential and hydrodynamic size of MgO/NiCoFe₂O₄-NH were −32.5 mV and 33.6 nm respectively. XAFS demonstrate that the MgO/NiCoFe₂O₄-NH possesses a highly ordered spinel-like structure with strong M–O and M–M interactions. Further, MgO/NiCoFe₂O₄-NH/GCE was fabricated by drop-casting method and tested for the electrochemical detection of AA and LEV using differential pulse voltammetry (DPV) in a 0.1 M Britton–Robinson buffer (pH 7). The calibration plot was drawn for AA and LEV in the concentration range of 0.05–400 µM (R² = 0.996) and 0.1–450 µM (R² = 0.995), respectively. The LODs/LOQs of AA and LEV were determined to be 0.013/0.043 and 0.0091/0.03, respectively. The developed MgO/NiCoFe₂O₄-NH/GCE represents a stable and reliable electrochemical platform with strong potential for simultaneous detection of AA and LEV in real samples.