Simultaneous Determination of Dopamine and Uric Acid by Electrocatalytic Oxidation on a Carbon Paste Electrode Using Pyrogallol Red as a Mediator

Ultrasensitive simultaneous detection of ascorbic acid, dopamine, uric acid and acetaminophen on a graphitized porous carbon-modified electrode

NHCS-1000/GCE produces a noticeable electrocatalytic response towards the anodic oxidation for the multiple sensing of AA, DA, UA and AC.

Microwave-assisted preparation of N-doped carbon dots as a biosensor for electrochemical dopamine detection

A new N-doped carbon dots (NCDs) could be prepared by using the microwave-assisted technique within 10 min without the need for any solvent or catalyst. The NCDs exhibited a highly sensitive electrochemical response toward dopamine (DA) in Phosphate Buffered Saline (PBS) (pH=6.5). The detection limit of DA was calculated by differential pulse voltammetry (DPV) as low as 1.2×10(-9) mol/L with a linear dynamic range of 5.0×10(-8) to 8.0×10(-6) mol/L. These results suggested that this new NCDs could be effectively used for the direct and rapid detection of trace levels of DA in human serum and urine samples.

Trace determination of cadmium in water using anodic stripping voltammetry at a carbon paste electrode modified with coconut shell powder

Background

Increasing awareness on the environmental impact of heavy metals has increased a considerable interest in the determination of metals in natural water bodies. The present paper describes the development and electrochemical application of carbon paste electrode modified with fibrous part of coconut shell for the determination of cadmium in water samples.

Methods

Determination was carried out using anodic stripping voltammetry. It is a two-step process. First, the metal ions get accumulated at the electrode surface at open-circuit potential, followed by a potential scan for voltammetric determination of cadmium.

Results

Different parameters affecting the determination of Cd (II) were optimized and are as follows: HCl as stripping solvent, acetate buffer of pH 5 as accumulating solvent, and 15-min accumulation time. Triton X-100, cetyltrimethylammonium bromide, and sodium dodecyl sulfate were used as representative for neutral, cationic, and anionic surfactants, respectively, to see the effect of surface active macromolecules. Interference caused by other metal ions on the determination of cadmium was also studied.

Conclusions

The method shows the development of a sensor for the sensitive determination of cadmium with limit of detection at 105 μg L−1. This technique does not use mercury and, therefore, has a positive environmental benefit.