Electrochemical Sensor Based on the Hierarchical Carbon Nanocomposite for Highly Sensitive Ciprofloxacin Determination

Metal-free Carbon Material Derived from Lantana Camara for the Detection and Removal of Ciprofloxacin

This work reports the preparation of a metal-free nitrogen and sulphur functionalized graphitic carbon sheets from a unique and less expensive precursor Lantana camara, which is a common hazardous weed in India. The synthesized material NS-CN-180 was successfully tested for the adsorption and removal of fluoroquinolone antibiotics ciprofloxacin. The surface morphology and elemental composition of NS-CN-180 were investigated through FESEM and XPS analyses. The SEM data reveals the graphitic sheets stacked onto each other with cavities in between them. The presence of various functional groups was identified through FT-IR spectroscopy and the degree of graphitization was calculated from XRD pattern. The probable mechanism of interaction for ciprofloxacin molecule with NS-CN-180 was also investigated with the help of FT-IR and zeta potential analyses. The fabricated material was found to be excellent for ciprofloxacin detection with a limit of detection value 16.08 nM. Also, the prepared material efficiently removes the 66.2% ciprofloxacin drug in 1 h. Adsorption and desorption experiments were performed to demonstrate the reusability of the material.

A Novel Composite Voltammetric Sensor Based on Yttria-Stabilized Zirconia Doped with Neodymium-Carbon Black-Nafion Glassy Carbon Electrode for Metoprolol Determination

For the first time, a new composite voltammetric sensor based on yttria-stabilized zirconia doped with neodymium-carbon black-Nafion glassy carbon electrode (YSZNd-CB-Nafion/GCE) for the determination of metoprolol (MET) has been developed. The instrumental parameters and supporting electrolyte were optimized. For 105 s accumulation time, linearity was achieved in the range of 0.01 to 0.2 µM. The limit of detection (for 105 s accumulation time) was equal to 2.9 nM (2 µg/L), and was the best result in comparison to other voltametric sensors. The reproducibility of the metoprolol signal presented as relative standard deviation (RSD) was equal to 1.9% (n = 7). Additionally, our electrode is characterized by high stability, is easy to use, and has a short preparation time. The proposed sensor was found useful for MET determination in plasma and urine, as well as for pharmaceutical samples, with a good recovery parameter (96-108%). Flow injection analysis (FIA) with amperometric detection was also performed for MET determination. The recovery was calculated and was in the range 101-103%, suggesting that the proposed material may be applied in flow injection analysis.