Simultaneous determination of ascorbic acid, dopamine, and uric acid with a highly selective and sensitive reduced graphene oxide/polypyrrole-platinum nanocomposite modified electrochemical sensor

Defective Prussian Blue Analogue with Cobalt for Fabrication of An Electrochemical Sensor for Detecting Ascorbic Acid, Dopamine and Uric Acid

“…The asymmetrical redox peak of AA (Figure 4a, yellow curve) and UA (Figure 4a, red curve) reveals their irreversible redox process which involves in a two‐electron transfer (Figure 4c). [37] Compared with AA and UA, DA has a more complicated electrochemical reaction (Figure 4c). At the acid pH of 6.0, DA would be protonated and main to occur a reversible or quasi‐reversible redox [Figure 4c, (i)], which reveals a pair of symmetrical redox peaks at ∼0.05 V (Figure 4a, blue curve).…”

“…[52] Under a diffusion control, a Q-t 1/2 plot will be linear (Figure 6b, 6e, 6 h) and the slope was the Cottrell slope of 2nFAD 1/2 C 0 /π 1/2 . From the Cottrell slope versus the concentration (Figure 5c, 5f, 5i), the value of D can be found to be 8.65 × 10 À 7 cm 2 s À 1 , 1.18 × 10 À 5 cm 2 s À 1 and 7.20 × [3,37,46,47] ChemElectroChem 10 À 6 cm 2 s À 1 for AA, DA and UA, respectively. In addition, the intercepts and slopes were obviously difference for blank PBS and for analytes (Figure S10a-S10c), further demonstrating the electrode reaction of the analytes was main controlled by diffusion.…”

“…Among the sensing materials, carbon materials with low toxicity and excellent conductivity were commonly used as modifier to improve the electrochemical performance of the sensor, including carbon nanotubes, [30] functionalized porous carbon, [31,32] graphenes such as reduced graphene oxide [33] and N-doped graphenes, [34,35] which are beneficial to the simultaneous determination of AA, DA and UA. To enrich the active sites and the catalytic activity, the noble metal nanoparticles [36,37] and some transition metals were incorporated in the modified layer, such as FeÀ Mn compound, [38] CoFe alloy, [39] especially cobalt, which was commonly act as the catalytic center to facilitate electrochemical redox of AA, DA and UA for the improvement of sensitivity. [40][41][42][43] Until now, the efforts on the fabrication of electrochemical sensor to achieve the higher sensitivity and the lower cost were necessary but still challenging.…”

“…The medium is PBS (pH 6.0) containing AA (0.40 mM), DA (5.0 μM) and UA (20 μM). (c) The proposed redox mechanisms of AA, DA and UA on the surface of PB-Co 750-1 /SPE [3,37,46,47].…”

Individual and simultaneous electrochemical determination of nitrofurantoin and ascorbic acid in biological samples using a novel La2YBiO6 double perovskite deposited on MWCNTs as a nanocomposite

“…As a result, the simultaneous selective, rapid, and reproducible determination of these molecules is important for analytical applications and diagnostic studies. 7 Several analytical methodologies for determining NFT and AA have been developed during the last few decades, including chromatography, fluorescence analysis, spectrophotometry, and electrochemical approaches. 8–11 Among them, the electrochemical approaches have received a lot of attention because of their unique benefits such as quick reaction, easy operation, and high sensitivity.…”