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|Type:||Artigo de periódico|
|Title:||Dna And Graphene As A New Efficient Platform For Entrapment Of Methylene Blue (mb): Studies Of The Electrocatalytic Oxidation Of β-nicotinamide Adenine Dinucleotide|
De Oliveira F.M.
|Abstract:||The modification of glassy carbon (GC) electrode with deoxyribonucleic acid (DNA) and grapheneis utilized as a new efficient platform for entrapment of methylene blue (MB). Electrochemical andelectroanalytical properties of the modified electrode (DNA/graphene/MB) were investigated by cyclicvoltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometry techniques. Cyclicvoltammetric results indicated the excellent electrocatalytic activity of the resulting electrode toward oxidation of β-nicotinamide adenine dinucleotide (NADH) at reduced overpotential (0.1 V vs. Ag/AgCl).It has been found that the DNA/graphene/MB modification has significantly enhanced the effective electrode response toward NADH oxidation. Cyclic voltammetry and rotating disk electrode (RDE) exper-iments indicated that the NADH oxidation reaction involves two electrons and an electrocatalytic rateconstant (kobs) of 1.75 × 106mol-1L s-1. The electrochemical sensor presented better performance in0.1 mol L-1phosphate buffer at pH 7.0. Other experimental parameters, such as the DNA, graphene, MB concentrations and the applied potential were optimized. Under optimized conditions, a linear response range from 10 μmol L-1to 1.50 mmol L-1was obtained with a sensitivity of 12.75 μA L μmol -1. The detection and quantification limits for NADH determination were 1.0 μmol L-1and 3.3 μmol L-1, respectively.© 2013 Elsevier Ltd. All rights reserved.|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
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