Sensitive electrochemical determination of epinephrine at poly(L-aspartic acid)/electro-chemically reduced graphene oxide modified electrode by square wave voltammetry in pharmaceutics

Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniques (Raman, infrared and energy-dispersive X-ray) as well as its morphology by scanning electron microscopy and compared to the analogously prepared reduced graphene oxide (rGO) and ruthenium oxide hexacyanoferrate (RuOHCF) thin films spectra and images. The results suggest that the improvement of the nanocomposite electrochemical activity is generated by the well-distributed RuOHCF nanometric particles over high-surfaced graphene sheets. Ethanol electrochemical oxidation in the rGO/RuOHCF modified electrode was performed in 0.1 mol L-1 NaCl (pH = 1.5) solution and it showed an anodic current peak starting at 0.9 V. Scan rate tests exhibited a diffusioncontrolled process not followed by any coupled chemical reaction. The determination of ethanol by amperometry coupled with batch injection analysis (BIA) system resulted in a wide linear range (20-400 mmol L-1) and good sensitivity (0.150 μA L mmol-1). The nanocomposite also showed application as an electrochemical sensor of ethanol in commercial samples mainly because of its easy preparation comparing to biosensors.

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Electrochemical determination of imidacloprid using poly(carbazole)/chemically reduced graphene oxide modified glassy carbon electrode

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2013.03.118 ◽

2013 ◽

Vol 183 ◽

pp. 102-109 ◽

Cited By ~ 38

Author(s):

Wu Lei ◽

Qiuju Wu ◽

Weimeng Si ◽

Zhenyan Gu ◽

Yuehua Zhang ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Electrochemical Determination ◽

Carbon Electrode ◽

Modified Glassy Carbon Electrode ◽

Reduced Graphene ◽

Chemically Reduced Graphene Oxide

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Hg(II) Analysis Using Poly(cysteine)-rGO Electrode

Sensor Letters ◽

10.1166/sl.2020.4202 ◽

2020 ◽

Vol 18 (3) ◽

pp. 179-187

Author(s):

J. Jency Feminus ◽

P. N. Deepa

Keyword(s):

Modified Electrode ◽

Metal Ion ◽

Square Wave Voltammetry ◽

Electrochemical Behaviour ◽

Electrochemical Determination ◽

Mercury Determination ◽

Selective Determination ◽

Wave Voltammetry ◽

Reduced Graphene

In the present work, we have developed a sensitive platform for the selective determination of Hg(II) ions based on reduced graphene oxide (rGO) electrode modified with poly cysteine (Poly-Cys). The Poly-Cys/rGO modified electrode was characterised by SEM, ATR-IR and its electrochemical behaviour was investigated through cyclic voltammetry and square wave voltammetry. The synergistic effect of rGO and poly-cysteine favoured the complexation of Hg(II) ions onto the surface of the modified electrode. The ions were then anodically stripped and the corresponding voltammograms recorded. The process of complexation followed by stripping was repeated with increasing concentrations of the metal ion. The linear range for the electrochemical determination of Hg(II) using the modified electrode was found to be from 0.05 to 2.7 μM with a detection limit of 0.006 μM. In addition, the electrode also exhibited good stability with negligible sensitivity towards interfering metal ions. The analytical applicability of the modified electrode was investigated by carrying out mercury determination in water samples obtained from various sources.

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