New contribution in the study of phase formation in mixed alkanethiol self-assembled monolayers: a powerful tool for transducers design

Author(s)

Coelho, Dyovani ^[1] ; Machado, Sergio A. S. ^[1]

Affiliation

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

• Document type: Journal article
• Source: Electrochimica Acta; v. 142, p. 191-201, OCT 1 2014.
• Web of Science Citations: 6

Abstract

Here, the formation of distinct 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) domains on polycrystalline gold surfaces was investigated by cyclic voltammetry and electrochemical quartz crystal nanobalance. Voltammetric experiments with the {[}Fe(CN)(6)](4-/3-) redox couple showed that the MPA SAM allowed electron transference at the same rate as the bare gold surface, while the MUA SAM blocked the entire electrode surface. The chemical nature of mixed SAMs is discussed by evaluating the mass variations and the respective molecular weight in the desorption potential regions for each thiol by electrochemical quartz crystal nanobalance. Different domains containing MUA, MPA and their mixtures were identified in the massograms, thus demonstrating MPA island domains and the electrochemical response obtained for the {[}Fe(CN)(6)](4-/3-) redox couple. The modified surfaces, as well as bare Au electrode, were used for electroanalysis of the flavonoid fisetin in Britton-Robinson buffer solution, pH 5. Depending on the modification, detection limits as low as 3.35 x10(-10) mol L-1, which attests the possibility of use such surfaces in electroanalysis. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 13/17053-0 - Development of an electroanalytical methodology for selective doping of electrodeposited selenium semiconducting films based in the underpotential deposition
• Grantee: Sergio Antonio Spinola Machado
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/07022-4 - Use of underpotential deposition in the dopping of electrodeposited selenium semiconductive films.
• Grantee: Dyovani Coelho
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 10/03813-4 - Development and characterization of bi-functional and nanoestructured Au-Pt surfaces and its application in biosensors for pesticides
• Grantee: Sergio Antonio Spinola Machado
• Support Opportunities: Regular Research Grants