Electrochemically selective determination of dopamine in the presence of ascorbic and uric acids on the surface of the modified Nafion/single wall carbon nanotube/poly(3-methylthiophene) glassy carbon electrodes.

A voltammetric method based on a combination of incorporated Nafion, single-walled carbon nanotubes and poly(3-methylthiophene) film-modified glassy carbon electrode (NF/SWCNT/PMT/GCE) has been successfully developed for selective determination of dopamine (DA) in the ternary mixture of dopamine, ascorbic acid (AA) and uric acid (UA) in 0.1M phosphate buffer solution (PBS) pH 4. It was shown that to detect DA from binary DA-AA mixture, the use of NF/PMT/GCE was sufficient, but to detect DA from ternary DA-AA-UA mixture NF/SWCNT/PMT/GCE was required. The later modified electrode exhibits superior electrocatalytic activity towards AA, DA and UA thanks to synergic effect of NF/SWCNT (combining unique properties of SWCNT such as high specific surface area, electrocatalytic and adsorptive properties, with the cation selectivity of NF). On the surface of NF/SWCNT/PMT/GCE AA, DA, UA were oxidized respectively at distinguishable potentials of 0.15, 0.37 and 0.53 V (vs. Ag/AgCl), to form well-defined and sharp peaks, making possible simultaneous determination of each compound. Also, it has several advantages, such as simple preparation method, high sensitivity, low detection limit and excellent reproducibility. Thus, the proposed NF/SWCNT/PMT/GCE could be advantageously employed for the determination of DA in real pharmaceutical formulations.

Quan do P ，Tuyen do P ，Lam TD ，Tram PT ，Binh NH ，Viet PH ... -  《-》

Highly selective and sensitive determination of dopamine using a Nafion/carbon nanotubes coated poly(3-methylthiophene) modified electrode.

Wang HS ，Li TH ，Jia WL ，Xu HY ... -  《BIOSENSORS & BIOELECTRONICS》

Electrocatalytic detection of dopamine in the presence of ascorbic acid and uric acid using single-walled carbon nanotubes modified electrode.

Single-walled carbon nanotubes (SWCNTs) fabricated by sodium dodecyl sulfate (SDS) (f-SWCNTs) modified glassy carbon electrodes (f-SWCNTs/GCE) for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The f-SWCNTs/GCE displayed very good electrochemical catalytic activities with respect to GCE. The oxidation over-potentials of DA and UA decreased dramatically, and their oxidation peak currents increased significantly at f-SWCNTs/GCE compared to those obtained at the bare GCE. Simultaneously, the oxidation peak currents of AA decreased accordingly. The f-SWCNTs/GCE not only divide the overlapping voltammetric responses of them into individual voltammetric peaks, but also totally eliminate the interference from AA and distinguish DA from UA. The catalytic peak currents obtained from square-wave voltammetry increased linearly with increasing DA concentrations in the range of 5.0×10(-6) to 1.0×10(-4)M with a detection limit of 2.0×10(-8)M (S/N=3). The method was also successfully applied for determination of DA and showed good recovery in some biological fluids.

Li Y ，Du J ，Yang J ，Liu D ，Lu X ... -  《-》

Overoxidized polypyrrole film directed single-walled carbon nanotubes immobilization on glassy carbon electrode and its sensing applications.

Li Y ，Wang P ，Wang L ，Lin X ... -  《BIOSENSORS & BIOELECTRONICS》

Electropolymerized film of functionalized thiadiazole on glassy carbon electrode for the simultaneous determination of ascorbic acid, dopamine and uric acid.

Kalimuthu P ，John SA 《-》