Electrochemical sensor based on multi-walled carbon nanotubes and 4-(((4-mercaptophenyl)imino)methyl) benzene-1,2-diol for simultaneous determination of epinephrine in the presence of acetaminophen

A carbon paste electrode modified with 4-(((4-mercaptophenyl)imino)methyl)benzene-1,2-diol (MIB) and multi-walled carbon nanotubes MIB /CNT/CPE) was prepared for determination of epinefrine (EP) in the presence of acetaminophen (AC). Cyclic voltammetry, chronoamperometry and differential pulse voltammetry (DPV) techniques were used to investigate the modified electrode for the electrocatalytic oxidation of (EP) and (AC) in aqueous solutions. The separation of the oxidation peak potential for EP- AC was 200 mV. Under the optimum conditions, the calibration curve for EP was obtained in the range of 1.0 to 25.0 µM and 25.0 to 500.0 µM. The diffusion coefficient for the oxidation of EP at the surface of modified electrode was calculated as 5.76×10-5 cm2s-1.</p

Thiosemicarbazide derivative-functionalized carbon nanotube for simultaneous determination of isoprenaline and piroxicam

Abstract Background Piroxicam (PX) is a nonsteroidal anti-inflammatory drug of the oxicam category that has been known worth as a chemopreventative, anti-tumor agent, for acute and chronic musculoskeletal. To the best of our knowledge, no paper has been published until now reporting the simultaneous electrocatalytic detection of isoprenaline and PX by using any type of modified electrodes. Methods The glassy carbon electrode modified with multiwalled carbon nanotubes chemically modified with (z)-1-(3,4-dihydroxybenzylidene)-2-methylthiosemicarbazide (DBT–CNT/GCE). The electrocatalytic behavior of analytes was examined using cyclic voltammetry (CV), chronoamperometry, and differential pulse voltammetry (DPV) on the modified electrode. Results In order to determine kinetic parameters such as the anodic transfer coefficient (α = 0.47) and the electron transfer rate constant between the nanocomposite and glassy carbon electrode (ks/s = 0.51), cyclic voltammetry was applied. The results represented a linear relationship versus isoprenaline concentrations in the wide range of 0.5–1500.0 μM and a detection limit of 0.35 μM. Furthermore, DPV was applied successfully for the simultaneous determination of isoprenaline and piroxicam. Conclusions This proposed sensor has been successfully applied to determine the IP and PX in blood serum human, which demonstrates that it has excellent potential application for detection of different concentrations of IP and PX