Nano-cerium zinc molybdate embedded with activated graphene for detection of levofloxacin in polluted water resources

Abstract

Antibiotics have widespread applications in personal care, animal muscle growth, and aquaculture, yet their pervasive use gives rise to substantial risks for human health and the ecosystem. Consequently, the imperative lies in developing accurate and highly sensitive detection techniques for analyzing levofloxacin (LFX). This research focuses on the hydrothermal synthesis of unique three-dimensional cubical-like ternary cerium-doped zinc molybdate (Ce@ZnMoO₄) nanostructures. Ultrasonic methods were used to integrate Ce@ZnMoO₄ with activated graphene (AGr) for LFX detection. X-ray diffraction, Raman spectroscopy, and field emission scanning electron microscopy were used to carefully analyze the resultant Ce@ZnMoO₄/AGr composite's physical characteristics. The covalent integration of cubic-like Ce@ZnMoO₄ with AGr produced a four-fold increase in sensor response compared to a Ce@ZnMoO₄-modified electrode and displayed remarkable electrocatalytic activity. Due to its unique electronic and catalytic properties, Ce@ZnMoO₄ synergistically interacts with the AGr layers. This synergy enhances conductivity, facilitating efficient electron transfer during electrochemical processes. Additionally, the composite offers a high surface area and numerous active sites, enabling more significant interaction between the electrode and the target analyte, LFX, thereby enhancing sensor response. The sensor demonstrated outstanding lower limits of detection (0.0031 µM), good sensitivity (0.3327 µA/µM cm^-2), and a quantification limit (0.0375 µM) under optimal conditions. Along with high specificity and outstanding storage stability, a broad linear range spanning from 0.025 to 845 µM was also found. The effectiveness of the sensor is further confirmed by the successful detection of LFX in aquatic samples.