Investigation of the Electrochemical Behavior of Mesalazine on the Surface of a Glassy Carbon Electrode Modified with CNT/PPY Doped by 1,5‐Naphthalenedisulfonic Acid

Abstract

A glassy carbon electrode (GCE) was modified with a thin layer of multiwalled carbon nanotubes (MWCNTs) and subsequently, electrochemically deposited poly‐pyrrole. The electrochemical behavior of mesalazine was studied on the surface of the modified electrode by applying linear sweep voltammetry (LSV). The electropolymerization process and the electrochemical response toward mesalazine were investigated in the presence of different aromatic anion dopants including, benzenesulfonic acid (BSA), 1,3‐benzenedisulfonic acid (1,3‐BDSA), 1,5‐naphthalenedisulfonic acid (1,5‐NDSA) and new coccine (NC). By using 1,5‐NDSA as dopant, a significant increase (∼418 times) in the peak current of mesalazine was observed, in comparison to the bare GCE. Experimental variables such as drop size of the cast MWCNTs suspension, pH of the supporting electrolyte, accumulation conditions and the number of scans in the electropolymerization process were optimized by monitoring the LSV responses of mesalazine. Under the optimum conditions, two linear dynamic ranges of 0.01–0.1 µmol L−1 and 0.1–1.0 µmol L−1 with a detection limit of 3 nmol L−1 were resulted for the voltammetric determination of mesalazine. The prepared electrode showed high sensitivity, stability and good reproducibility for determination of mesalazine. These properties made the prepared sensor suitable for the determination of mesalazine in pharmaceutical and clinical preparations.

Hybrid Nanocomposite Platform, Based on Carbon Nanotubes and Poly(Methylene Blue) Redox Polymer Synthesized in Ethaline Deep Eutectic Solvent for Electrochemical Determination of 5-Aminosalicylic Acid

“…In acid media, the amino group of 5-ASA is protonated and hinders the oxidation process, which requires higher potential values. Above pH 6, the oxidation of 5-ASA occurs at a lower potential, as the -NH 2 group is no longer protonated (p K a2 = 5.8) [ 39 ]. No influence of the 5-ASA electrochemical process was observed when the PMB oxidation mechanism was investigated ( Figure S1, Supplementary Materials ).…”

Electrochemical sensing of mesalazine and its N-acetylated metabolite in biological samples using functionalized carbon nanotubes

“…Also compared with other methods, the linearity range obtained at proposed electrochemical sensor for 5-ASA was in the lower concentration range. The CNT-N/GCE with adsorptive accumulation of 30 s exhibited a similar linear range as GCE modified with nanoporous film and electrochemically deposited polypyrrole after 90 s accumulation step (slope of the calibration plot was 1.36 Â 10 5 mA M À 1 ) [25], but the improved sensitivity was obtained in the case of CNT-N/GCE (slope of the calibration plot was 2.33 Â 10 7 ). In relation to other electroanalytical methods for determination of 5-ASA, the LOD obtained with direct SWV measurement at CNT-N/GCE is similar, or even better using adsorptive accumulation of drug molecules on the porous thin film at its surface, than those found with other electrodes.…”

“…In relation to other electroanalytical methods for determination of 5-ASA, the LOD obtained with direct SWV measurement at CNT-N/GCE is similar, or even better using adsorptive accumulation of drug molecules on the porous thin film at its surface, than those found with other electrodes. The lower LOD value showed only the GCE modified using layer by layer procedure with nanofilm deposition and subsequently electropolimerization of pyrrole in the presence of aromatic anion dopant [25], however, the CNT-N/GCE can be easier fabricated in a simple and fast procedure and the surface of electrode is also easily renewable.…”

“…The high cost of enzymes used in the kit limits widespread application of the method for routine purpose. The oxidative behavior of 5-ASA was studied on the surface of GCE modified with nanoporous film and subsequently, electrochemically deposited polypyrrole using 1,5-naphtalenedisulfonic acid as dopant [25], however the developed method was designed only for quantitation of 5-ASA. Due to prolonged therapy and maintenance of remission in inflammatory bowel diseases, as well as the need for clinical and bioequivalence studies after the administration of newly developed delayed-release formulations, a simple, inexpensive and highly sensitive electroanalytical method is in great demand for simultaneous determination of 5-ASA and its metabolite.…”

Carbon Nanotube-Conducting Polymer Composites as Electrode Material in Electroanalytical Applications

“…Pyrrole (Py), which is one of the most commonly used CPs, was electropolymerized on CNT/ E surface mostly by CV [24][25][26]. Polypyrrole (PPy) was formed on single-stranded DNA (ssDNA)/MWCNT paste electrode in the range 0 to +0.75 V versus saturated calomel electrode (SCE) with 50 mV s -1 for six cycles in 0.1 M PBS (pH 7.0) containing 0.05 M Py and 2.0×10 -5 M 32-mer probe oligonucleotide for the electrochemical detection of DNA hybridization [27].…”