Preparation of Bimetallic Au-Pd/MWCNTs Electrode for Detection of Dopamine

Abstract

In this study, functionalized bimetallic Au-Pd on multi-walled carbon nanotubes (AuPd/MWCNT) are prepared and their application as electrochemical sensor materials for dopamine detection is explored. Furthermore, the as-prepared composite materials are identified using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectrometer (XPS). In addition, the experimental results show that AuPd/MWCNT displayed excellent sensing properties to dopamine. Especially, 1% Pd-5% Au/MWCNT showed a wide detection range (0.98–200 μM) and a low detection limit of 0.058 μM for dopamine. The sensor also displayed properties such as repeatability, reproducibility, and stability, which can be ascribed to the large specific surface area and the synergistic effect of the bimetallic nanoparticles. Therefore, the prepared functionalized multi-walled carbon nanotubes have good application prospects in the field of dopamine detection.

Gold–graphitic carbon nitride composite electrode for pimobendan detection

“…To determine whether the redox process was controlled by adsorption or diffusion, we investigated the association between redox currents and scan rate. If a linear association between peak current and sweep rate is observed, it usually indicates that an adsorbed molecule is controlling the process [16]. If a linear relation between peak current and square root the of the scan rate is observed, it reveals that the molecule is controlling the diffusion process.…”

“…In Figure 11c, the linearity of the curve is of low value compared with that shown in Figure 11b. According to these results, the redox reaction of pimobendan on the modified electrode is an adsorption‐controlled process, indicating direct adsorption of pimobendan on the electrode surface [16]. We selected a scan rate of 50 mV s −1 for ease of peak separation (Figure 11a).…”

“…Graphitic carbon nitride (g-C 3 N 4 ) is a two-dimensional organic semiconductor with a high specific surface area; additionally, g-C 3 N 4 owns high electrical conductivity for its sole delocalized conjugated structure [22][23][24][25][26]. Au is applied in promotion of some oxidation-reduction reactions and electrochemical reaction system [12,16,21]. The binding of pimobendan molecules on nano Au increased the electron transfer, yielding the modification in response current.…”

A novel double‐sampled square‐wave voltammetric technique combined with quadruple‐disk metallic‐glassy carbon electronic tongue for isotonic beverages profiling

“…The response of these electrodes is influenced by the difference in the electronic properties between the two metals, which can result in enhanced response parameters. Examples of such electrodes can be: bimetallic Au-on-Pd nanoparticles applied with a modified GCE used in determination and monitoring of 4-nitroaniline in environmental samples [27], immobilized polypyrrole conducting with bimetallic PtÀ Pd nanoparticles applied for oxidation of 4-(hydroxymethyl) pyridine [28], glassy carbon electrode modified with nanocomposite prepared from Co-Nd bimetallic nanoparticles, alumina nanoparticles and functionalized multiwalled carbon nanotubes, made through simple mechanical mixing applied in determination of epinephrine [29], CuÀ Pt bimetallic nanocatalysts deposited on borondoped diamond electrodes for the simple and rapid detection of methanol [30] or bimetallic AuÀ Pd on multiwalled carbon nanotubes for detection of dopamine [31].…”

Fabrication of Gold-Graphitic Carbon Nitride Composite Electrode for the Detection of Pimobendan

“…To conclude whether the redox process is controlled by a diffusion or adsorption, this study considered the relationship between oxidation current and scan rate. If it appears a linear relationship of peak current with sweep rate, then it usually means an adsorbed pimobendan molecule is controlled [16]. At pH =7.0 the CV method was used of scan rates ranging from 10 to 200 mVs -1 on oxidation current intensity at a pimobendan concentration at 55 μM.…”