Sensitive determination of nitric oxide using an electrochemical sensor based on MWCNTs decorated with spherical Au nanoparticles

Autor(es)

Maluta, Jaqueline R. ^[1] ; Canevari, Thiago C. ^[1] ; Machado, Sergio A. S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Solid State Electrochemistry; v. 18, n. 9, p. 2497-2504, SEP 2014.
• Citações Web of Science: 7

Resumo

This paper describes the synthesis, characterisation and application of a very sensitive electrochemical sensor based on a glassy carbon electrode modified with multiwalled carbon nanotubes (MWCNTs) decorated with homogeneously distributed spherical gold nanoparticles (AuNPs). These AuNPs presented diameters ranging from 2 to 10 nm. The AuNPs were prepared directly on the MWCNTs' surface via a synthesis using HAuCl4 and citric acid as the reducing agent. The resulting material (Au/MWCNTs) was characterised by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Raman spectroscopy. The developed Au/MWCNTs sensor was used in the determination of nitric oxide (NO) in phosphate buffer solution at pH 4.4 by differential pulse voltammetry. In the potential window between 0.5 and 0.65 V, a well-defined oxidation peak was observed, whose height was proportional to the NO concentration in the solution. The Au/MWCNTs-modified electrode exhibited high sensitivity for the determination of nitric oxide, with the limit of detection being 0.21 nmol L-1 (S/N = 3). No significant interference was detected for nitrite and CO2 in the NO detection. Our study demonstrated that the resultant Au/MWCNT-modified electrode can be used for nitric oxide detection in the presence of ascorbic acid, dopamine and uric acid, being potentially useful for determinations of NO in real samples. (AU)

• Processo FAPESP: 11/23047-7 - Desenvolvimento de biosensor eletroquímico utilizando sílica mesoporosa contendo nanotubos de carbono obtida pelo processo sol-gel. Determinação eletroquímica de pesticidas
• Beneficiário: Thiago da Cruz Canevari
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado