Fluid-Specific Detection of Environmental Pollutant Moxifloxacin Hydrochloride Utilizing a Rare-Earth Niobate Decorated Functionalized Carbon Nanofiber Sensor Platform

The development of precise and efficient detection methods is essential for the real-time monitoring of antibiotics, especially in environmental and biological matrices. This study aims to address this challenge by introducing a novel electrochemical sensor for the targeted detection of moxifloxacin hydrochloride (MFN), a fourth-generation fluoroquinolone. The sensor is based on a holmium niobate (HNO) and functionalized carbon nanofiber (f-CNF) nanocomposite, synthesized via a hydrothermal approach and subsequently characterized for its structural and electrochemical properties. When deposited onto a glassy carbon electrode (GCE), the HNO/f-CNF nanocomposite demonstrated exceptional electrochemical performance, as assessed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The sensor exhibited remarkable sensitivity, with a detection limit of 0.034 μM, a quantification limit of 0.11 μM, and a sensitivity of 0.69 μA μM^-1 cm^-2. It also achieved a broad linear detection range from 0.001 μM to 1166.11 μM, making it highly effective for MFN detection across various complex matrices, including environmental waters, biological fluids, and artificial saliva, with recovery rates between 98.15% and 101.75%. The novelty of this work lies in the unique combination of HNO's catalytic properties and f-CNF's enhanced electron transport, establishing a highly selective and sensitive platform for MFN detection. This sensor not only advances the field of electrochemical sensing but also offers a promising tool for real-time environmental and pharmaceutical monitoring.