Electroanalysis of Norepinephrine at Bare Gold Electrode Pure and Modified with Gold Nanoparticles and S‐Functionalized Self‐Assembled Layers in Aqueous Solution. Part II

Abstract

Gold electrodes modified with S-containing compounds and gold were used for determination of norepinephrine (NEP) in aqueous solution. A linear relationship between norepinephrine concentration and current response was obtained in the range of 0.1 mM to 600 mM with the detection limit 0.090 mM for the electrodes modified at 2D template and in the range of 0.1 mM to 700 mM with the detection limit 0.075 mM for the electrodes modified at 3D template. The results have shown that modified electrodes could clearly resolve the oxidation peaks of norepinephrine, ascorbic (AA) and uric acid (UA) with peak-to-peak separation enabling determination of NEP, AA and UA in the presence of each other.

Determination of Norepinephrine Alone and in the Presence of Ascorbic and Uric Acids Using a Gold Electrode Modified with Gold Nanoparticles and Self‐Assembled Layers of meso‐2,3‐Dimercaptosuccinic Acid

“…The monodisperse gold sol solution used in the present studies contained gold nanoparticles (Au‐NPs) of the average diameter of 14 nm, as evaluated from the transmission electron microscopy image (TEM) and accordingly the UV‐Vis spectrum presented shows one band with a maximum at λ max =523 nm. The diameter of gold nanoparticles obtained in this work is comparable to that obtained earlier 16, 17. It is noteworthy, that Au colloids of similar characteristics were prepared also by other researchers 20–22 who used the same procedure as described in this paper.…”

“…The CVs obtained with the ternary mixture containing: norepinephrine, ascorbic acid and uric acid show, that oxidation peaks assigned to oxidation of these compounds are clearly separated from each other. It should be kept in mind that norepinephrine at pH 7 exists in its cationic form (p K a =8.74 34) while ascorbic acid (p K a =4.1 17) and uric acid (p K a =5.4 17) in their anionic forms. Thus, the positive potential shift of the peak currents of ascorbic acid and uric acid can be attributed to a repulsive interaction between the COO − groups of ascorbic acid and uric acid and the negatively charged COO − groups of meso ‐2,3‐dimercaptosuccinic acid layer and/or the negatively charged Au nanoparticles stabilized by citrate anions 35.…”

“…Nevertheless, literature provides evidence on using modified carbon electrodes for simultaneous biosensors of norepinephrine, ascorbic acid and uric acid 7–15. Moreover, the material frequently used for the preparation of the modified electrodes used for selective determination of norepinephrine is gold because of its inertness and good affinity to gold nanoparticles and sulfur 16, 17. Despite of a lot of different materials used for norepinephrine sensing, the development of novel materials with simple preparation method for simultaneous determination of neurotransmitters and interfering biogenic molecules is still a challenging task for electrochemists.…”

A multiporous electrochemical sensor for epinephrine recognition and detection based on molecularly imprinted polypyrrole

“…18 A chemiluminescence method was employed by Michalowski et al to detect EP in the two-channel manifold. 19 In that work, EP could be determined in pharmaceutical preparations with a detection limit of 0.2 mg L 21 . While these approaches are fully adequate in terms of their accuracy, they do require expensive instrumentation, highly skilled technicians, and complicated and timeconsuming procedures.…”

Highly sensitive determination of epinephrine by a MnO2/Nafion modified glassy carbon electrode

“…Recently, an enormous amount of research has been devoted to the development of new modified electrode for monitoring EP [19]. Gold electrodes modified with S-containing compounds and gold nanoparticles have been used for determination of norepinephrine in aqueous solution [20]. The sensor exhibits excellent stability and reproducibility.…”