Carbon ceramic electrodes modified with mixed oxides SiO2/SnO2 for determination of levofloxacin

Abstract

The preparation of a carbon ceramic electrode modified with SnO 2 (CCE/SnO 2 ) using tin dibutyl diacetate as precursor was optimized by a 2 3 factorial design. The factors analyzed were catalyst (HCl), graphite/organic precursor ratio, and inorganic precursor (dibutyltin diacetate). The statistical treatment of the data showed that only the second-order interaction effect, catalyst × inorganic precursor, was significant at 95% confidence level, for the electrochemical response of the system. The obtained material was characterized by scanning electron microscopy (MEV), X-ray diffraction (XRD), RAMAN spectroscopy, XPS spectra, and voltammetric techniques. From the XPS spectra, it was confirmed the formation of the Si-O-Sn bond by the shift in the binding energy values referred to Sn 3d3/2 due to the interaction of Sn with SiOH species. The incorporation of SnO 2 provided an increment of the electrode response for levofloxacin, with Ipa = 147.0 μA for the ECC and Ipa = 228.8 μA for ECC/SnO 2 , indicating that SnO 2 when incorporated into the silica network enhances the electron transfer process. Under the optimized working conditions, the peak current increased linearly with the levofloxacin concentration in the range from 6.21×10 −5 to 6.97×10 −4 mol L −1 with quantification and detection limits o f 3 . 8 0 × 1 0 − 5 m o l L − 1 ( 1 4 . 0 7 m g L − 1 ) a nd 1.13×10 −5 mol L −1 (4.18 mg L −1 ), respectively.

Effect of Different Carbon Blacks on the Simultaneous Electroanalysis of Drugs as Water Contaminants Based on Screen‐printed Sensors

“…Currently, the use of electroanalytical methods for determination of LVF and ACP, involves the quantifica-tion of individual drug or the combination one with other of the same therapeutic group [7][8][9][10][11][12]. However, the simultaneous determination of these drugs is very important because some patients undergoing clinical treatment are treated simultaneously with drugs of different therapeutic groups.…”

Electrochemical Determination of Levofloxacin Using Poly(Pyrogallol Red) Modified Glassy Carbon Electrode

“…Besides these advantages, conventional electrodes used in electrochemical measurements have poor performance due to the easy fouling of their surfaces by the analyte and the intermediate products formed by the electrode reaction. For this reason, the surfaces of carbon-based electrodes have been altered by utilizing a wide range of modifiers such as nanostructured noble metals [18] and metal oxides, [11,19] carbon-based nanomaterials such as graphene (GR), [20] graphene oxide (GO), [4,6,21,22] carbon nanotube (CNT) [23] and conductive polymers [2,5,20,24] for selective and sensitive LEV detection. Conductive polymers are one of the most frequently used modifiers due to their homogeneity, repeatability, good stability, and strong adhesion to the electrode surface.…”