MXene-derived potassium titanate nanoribbon-decorated electrode architecture for the detection of ciprofloxacin: development of a multipurpose sensing platform promoting One Health

Abstract

Recent studies have highlighted the promise of MXene-derived titanate nanoribbons (KTNR) as electrode materials for electrochemical sensing applications. This work investigates the electrochemical activity of potassium titanate nanoribbons synthesized from MXene for the development of a voltammetric sensor for ciprofloxacin detection. The sensor offers a sustainable approach for ciprofloxacin quantification, addressing critical needs in food safety, environmental monitoring, and healthcare diagnostics, ultimately contributing to the United Nations’ Sustainable Development Goals by mitigating antimicrobial resistance and supporting the One Health initiative. To initiate the experiments, the structural, stability/energetics, and electronic features of two dimer complexes, KTNR/ciprofloxacin and MXene/ciprofloxacin, had been computationally inspected using two in silico tools, and some important electronic parameters such as binding energy, HOMO–LUMO gap and dipole moment showed that the former one (KTNRs) was significantly more sensitive than the MXene with ciprofloxacin. 2D Ti₃C₂ MXene served as the precursor for the synthesis of potassium titanate nanoribbons. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), elemental mapping, and energy-dispersive X-ray spectroscopy (EDX) techniques were employed to confirm the crystallinity, surface morphology, and layered structure of the synthesized nanoribbons. Atomic force microscopy (AFM), contact angle measurement and surface profilometry were used to characterize the fabricated electrode surface. The electrochemical and sensing properties of the materials were further evaluated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Subsequently, the nanoribbons were deposited onto a glassy carbon electrode (GCE) surface. The electro-oxidation behaviour of ciprofloxacin was then investigated using CV, DPV, and square wave voltammetry (SWV) in an optimized 0.1 M phosphate buffer solution (pH 8). The developed sensor exhibited a remarkable linear detection range of 0.6 μM (≈0.03 μg mL⁻¹) to 147.2 μM (≈7.18 μg mL⁻¹) for ciprofloxacin. Additionally, the limit of detection (LOD) achieved was 0.07, 0.0608, and 0.0264 μM for CV, DPV, and SWV, respectively. Notably, the electrodes demonstrated excellent selectivity towards ciprofloxacin detection in complex matrices, including marine water, river water, agricultural soil, organic fertilizer, milk, honey, poultry eggs, and simulated body fluids.