Electrochemical detection of enrofloxacin and ciprofloxacin based on mesoporous La2O2CO3 nanostructures – an eco-friendly electrode material for sustainability

Administration of antibiotics in the modern world has posed a serious threat to induce antimicrobial resistance (AMR), which concerns the Sustainable Development Goals (SDGs). Fluoroquinolone group antibiotics, namely enrofloxacin and ciprofloxacin, are predominantly responsible for undermining the One Health. In this context, to provide an eco-friendly and robust approach, a green electrochemical sensor has been fabricated with lanthanum oxycarbonate (La₂O₂CO₃) nanoparticles for the detection of enrofloxacin and ciprofloxacin in several complex matrices, related to food safety, environmental monitoring, and human health. The green synthesis methodology was adopted for the synthesis of the oxycarbonate material, while the phytochemicals present in the leaves of Sida acuta played the role of reducing and capping agents. To characterize the crystallinity and morphology of the synthesized material, several spectroscopic (XRD, BET, EDAX) and microscopic (FESEM, TEM) techniques were employed. The fabricated electrodes were characterized by atomic force microscopy (AFM), goniometry, and surface profilometry. The fabricated voltammetric sensor demonstrated an efficient linear range of 2.77 µM to 158.99 µM and 5.98 µM to 57.87 µM in the case of enrofloxacin and ciprofloxacin, respectively. In both cases, cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV) have been employed as electrochemical analytical techniques. The limit of detection (LOD) was achieved to be 4.07 µM, 2.91 µM, and 4.98 µM, while the limit of quantification (LOQ) was achieved to be 14.2 µM, 8.83 µM, and 15.1 µM in CV, DPV, and SWV, respectively, for the detection of enrofloxacin. On the other hand, the LOD was achieved to be 2.85 µM, 1.90 µM, and 1.65 µM, while the LOQ was found as 8.64 µM, 5.7 µM, and 5.01 µM in CV, DPV, and SWV, respectively, for the detection of ciprofloxacin.