Sensitive and Selective Determination of Uric Acid by Modified Glassy Carbon Electrodes with Multi-Walled Carbon Nanotubes Dispersed in Nafion ® . Electroanalytical Applications for the Development as Sensors

2017 ◽  
Vol 76 (1) ◽  
pp. 119-131 ◽  
Author(s):  
Alejandro Gutiérrez ◽  
Maria Luisa Lozano Camargo ◽  
Laura Galicia
Keyword(s):  
Carbon Nanotubes ◽  
Uric Acid ◽  
Glassy Carbon ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Selective Determination ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

scholarly journals Highly Selective Determination of Dopamine in the Presence of Ascorbic Acid and Serotonin at Glassy Carbon Electrodes Modified with Carbon Nanotubes Dispersed in Polyethylenimine

2008 ◽  
Vol 8 (11) ◽  
pp. 6003-6009 ◽  
Author(s):  
Marcela C. Rodríguez ◽  
María D. Rubianes ◽  
Gustavo A. Rivas
Keyword(s):  
Carbon Nanotubes ◽  
Ascorbic Acid ◽  
Glassy Carbon ◽  
Carbon Electrodes ◽  
Acid Oxidation ◽  
Promising Alternative ◽  
Glassy Carbon Electrodes ◽  
Multi Wall Carbon Nanotubes ◽  
Selective Determination

We report the highly selective and sensitive voltammetric dopamine quantification in the presence of ascorbic acid and serotonin by using glassy carbon electrodes modified with a dispersion of multi-wall carbon nanotubes (MWCNT) in polyethylenimine, PEI (GCE/MWCNT-PEI). The electrocatalytic activity of the MWCNT deposited on the glassy carbon electrode has allowed an important decrease in the overvoltages for the oxidation of ascorbic acid and dopamine, making possible a clear definition of dopamine, serotonin and ascorbic acid oxidation processes. The sensitivities for dopamine in the presence and absence of 1.0 mM ascorbic acid and serotonin were (2.18±0.03 × 105 μAM−1 (r = 0.9998); and (2.10±0.07 × 105 μAM−1 (r = 0.9985), respectively, demonstrating the excellent performance of the GCE/MWCNT-PEI. The detection limit for dopamine in the mixture was 9.2 × 10−7 M. The R. S. D. for the determination of 50 μM dopamine using four different electrodes was 3.9% when modified with the same MWCNT/PEI dispersion, and 4.6% when using four different dispersions. The modified electrode has been successfully applied for recovery assays of dopamine in human blood serum. Therefore, the new sensor represents an interesting and promising alternative for the electrochemical quantification of neurotransmitters and other analytes of clinical interest.

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