Fabrication of a new multi-walled carbon nanotube paste electrode for stripping voltammetric determination of Ag(i)

Abstract

A new modified carbon paste electrode based on multi-walled carbon nanotubes and a synthesized Schiff base of N,N'-bis(2-hydroxybenzylidene)-2,2'(aminophenylthio) ethane, acting as a chelating agent for Ag(I) ions, is described. The electroanalytical procedure for the determination of Ag(I) was comprised of two steps: the chemical accumulation of the analyte under open-circuit conditions followed by replacing the medium with a 0.1 M HCl solution where the accumulated Ag(I) was reduced for 20 s in -0.7 V. The potential was then scanned from -0.2 to +0.2 V to obtain the voltammetric peak. The effective parameters in the sensor response were examined. Under optimized operational conditions, a linear response range from 0.5-200 ng mL(-1) was obtained. The detection limit for silver determination was 0.092 ng mL(-1). For 7 successive determinations of 15.0 and 60.0 ng mL(-1) of Ag(I), relative standard deviations of 2.2% and 1.2% were obtained, respectively. The procedure was applied in determining Ag(I) in X-ray photographic films and water samples.

Adsorptive Voltammetry for the Determination of Ochratoxin A Using Enrichment Effect by Cationic Surfactants

“…The electrochemical behavior of OTA at the CNTP electrode was investigated by cyclic voltammetry. Carbon nanotubes are characterized by high electronic conductivity, mechanical resistance, and electrode active surface area (leading to enhanced electrochemical responses), and an anti‐fouling effect on the electrode surface . In Figure (A), the cyclic voltammogram is reported as it corresponds to the response of a 5.0×10 −5 M OTA solution, and was obtained using a CNTP electrode at a scan rate of 50 mV/s.…”

Carbon Nanotubes Heavy Metal Detection with Stripping Voltammetry: A Review Paper

“…Analytical techniques of inductively coupled plasma‐mass spectrometry, atomic absorption spectroscopy, atomic fluorescence spectroscopy and electrochemistry are commonly used for heavy metal detection . Stripping voltammetry, as one of the most sensitive electrochemical techniques for metal determination, has been reported extensively for detection of Pb, Cd, Hg, As, Zn, Cu, Ag, Cr, Ni, and Ti, etc . CNTs, as well as other carbon nanostructures, offer distinctive advantages of large surface area, fast electron transfer rate, high sensitivity and low cost hence have been widely researched for use in electrochemical metal ion sensing .…”

Selective voltammetric determination of Cu(II) based on multiwalled carbon nanotube and nano-porous Cu-ion imprinted polymer

“…Moreover, CNTs have been the subject of numerous investigations in chemical, physical and material areas due to their novel structural, mechanical, electronic and chemical properties [30,31]. The modification of electrode substrates with multiwalled carbon nanotubes (MWCNTs) for use in analytical sensing has been documented to result in low detection limits, high sensitivities, reduction of overpotentials and resistance to surface fouling [32][33][34].…”