Highly efficient detection of ofloxacin in water by samarium oxide and β-cyclodextrin-modified laser-induced graphene electrode

We developed a new electrochemical sensor that detects ofloxacin (OFL) in water by depositing β-cyclodextrin (β-CD) and samarium oxide nanoparticles (Sm2O3 NPs) onto a laser-induced graphene (LIG) electrode. Scanning electron microscopy, Transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, contact angle measurements, and electrochemical impedance spectroscopy were used to characterize β-CD/Sm2O3 NPs/LIG electrodes. Our results showed that the improved electrochemical activity is due to the excellent electrocatalytic performance of Sm2O3 NPs, improving electron transfer efficiency. The deposition of β-CD improves electrode hydrophilicity and increases the adsorption capacity of OFL on the electrode surface. The synergistic effect of two modification compositions can promote OFL detection. The enhanced adsorption energy and improved electron transfer characteristics were also confirmed by density functional theory calculations. Under optimal detection conditions, the sensor achieves a wide linear range (0.01 ∼ 1.0 μmol/L and 1.0 ∼ 120 μmol/L) and a low detection limit (0.005 μmol/L) with good anti-interference ability and stability. This sensor has also been successfully applied to the detection of OFL in tap water and lake water. These results show that the developed sensor is a promising step towards rapid in situ detection of OFL in water environments.