In-situ growth of small-size Fe 3 O 4 nanoparticles on N-doped hollow carbon spheres for electrochemical high-efficiency determination of ofloxacin-contaminated water

To prevent antibiotic water contamination, efficient electrode materials for the preparation of electrochemical sensors for detection are urgently needed. Herein, we report on the fabrication of an electrode material for the in-situ growth of Fe 3 O 4 nanoparticles on N-doped hollow carbon spheres (N-HCS/Fe 3 O 4 NPs) as an electrochemical sensor for the detection of ofloxacin-contaminated water. N-doped hollow carbon spheres (N-HCS) were prepared by the CaCO 3 template method, and N-HCS/Fe 3 O 4 NPs were prepared via hydrothermal. The combination of Fe 3 O 4 and N-HCS enhances the overall electron transfer capability of the N-HCS/Fe 3 O 4 NPs. The detection effect of the N-HCS/Fe 3 O 4 NPs electrochemical sensor on ofloxacin (OFL) was evaluated using differential pulse voltammetry (DPV). The results showed that the limit of detection (LOD) of the electrochemical sensor was 0.028 μM (S/N = 3), and the sensitivity was 0.023 μA/μM in the linear working range of 0.096–40 μM. The electrochemical sensor has satisfactory interference rejection and good stability, and has been successfully applied to the detection of actual OFL-contaminated water. This work highlights the superiority of in-situ growth of Fe 3 O 4 nanoparticles on N-HCS for high-efficiency electrochemical OFL contamination detection.