Nanocomposite of ferricyanide-doped chitosan with multi-walled carbon nanotubes for simultaneous senary detection of redox-active biomolecules

Simultaneous Determination of Four DNA bases at Graphene Oxide/Multi-Walled Carbon Nanotube Nanocomposite-Modified Electrode

“…All these values were close to the Nernstian theoretical value of 59.1 mV/pH which indicated that there was an equal number of protons and electrons exchanged for each analyte in the electrochemical oxidation mechanisms [31]. These experimental results matched with previous literature records [11,22,28,[31][32][33][34]. As shown in the reaction scheme (1)-(3) and (5) of Scheme 2, two protons and two electrons were postulated to be involved in rate determining steps of electrochemical oxidations of UA G, A, and C [11,22,31,32,34].…”

“…Excellent linear dependence was observed between I p and concentrations for each analyte as illustrated in Figure 8. As shown in Figure 8, two linear segments were obtained for UA, G, and A [28,36]. Linear ranges for detecting UA were from 1 µM to 31 µM with calibration Equation (1) and from 31 µM to 151 µM with calibration Equation (2).…”

“…Additionally, the natural polymer, CHT, is used as a dispersing material in the modification steps of GCE surfaces [22]. An ideal candidate for sensor fabrication is CHT due to its unique properties such high stability, biocompatibility, good adhesion and insolubility in water [27,28].…”

Simultaneous Trace Electrochemical Determination of Xanthine Theophylline and Theobromine with a Novel Sensor Based on a Composite Including Metal Oxide Nanoparticle Multi‐walled Carbon Nanotube and Nano‐Na‐montmorillonite Clay

“…The slope values are close to the Nernstian slope of 0.059 V/pH for XT and TP that are consistent with the data in the literature, indicating that the oxidation mechanism of XT and TP on the electrochemical sensor involves an equal number of protons and electrons (two protons: two electrons) [45,46,47]. A slope of 0.019 V/pH for TB is approximately one-third of the Nernstian slope of 0.059 V/pH, which is consistent with literature data revealing that the electrooxidation mechanism is a twostep oxidation process involving 4 protons:4 electrons [8,14,47].…”

Ferrocene‐Functionalized Multiwalled Carbon Nanotubes for the Simultaneous Determination of Dopamine, Uric Acid, and Xanthine

“…Electrodes can readily be modified and fabricated using different materials and technologies such as, nanomaterials, nanocomposite, quantum dots, binary oxides, laser [11,29,30] . Among these modification techniques, nanocomposite produced better separation and resolution of oxidation peaks for simultaneous determination DA, UA, and XA [31–36] . Still finding a simple, cheap, and stable modifier with excellent peaks separation for the DA, UA, and XA with LOD lower than μM is a big challenge in electrochemistry.…”