All-Diamond Microelectrodes as Solid State Probes for Localized Electrochemical Sensing.

Autor:	Silva EL; †CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal., Gouvêa CP; §Materials Metrology Division, INMETRO, 25250-020, Duque de Caxias, Rio de Janeiro, Brazil., Quevedo MC; †CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal., Neto MA; †CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal., Archanjo BS; §Materials Metrology Division, INMETRO, 25250-020, Duque de Caxias, Rio de Janeiro, Brazil., Fernandes AJ; ‡I3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal., Achete CA; §Materials Metrology Division, INMETRO, 25250-020, Duque de Caxias, Rio de Janeiro, Brazil., Silva RF; †CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal., Zheludkevich ML; †CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal.; ⊥MagIC, Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck Str. 1, 21502 Geesthacht, Germany., Oliveira FJ; †CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal.
Jazyk:	angličtina
Zdroj:	Analytical chemistry [Anal Chem] 2015 Jul 07; Vol. 87 (13), pp. 6487-92. Date of Electronic Publication: 2015 Jun 24.
DOI:	10.1021/acs.analchem.5b00756
Abstrakt:	The fabrication of an all-diamond microprobe is demonstrated for the first time. This ME (microelectrode) assembly consists of an inner boron doped diamond (BDD) layer and an outer undoped diamond layer. Both layers were grown on a sharp tungsten tip by chemical vapor deposition (CVD) in a stepwise manner within a single deposition run. BDD is a material with proven potential as an electrochemical sensor. Undoped CVD diamond is an insulating material with superior chemical stability in comparison to conventional insulators. Focused ion beam (FIB) cutting of the apex of the ME was used to expose an electroactive BDD disk. By cyclic voltammetry, the redox reaction of ferrocenemethanol was shown to take place at the BDD microdisk surface. In order to ensure that the outer layer was nonelectrically conductive, a diffusion barrier for boron atoms was established seeking the formation of boron-hydrogen complexes at the interface between the doped and the undoped diamond layers. The applicability of the microelectrodes in localized corrosion was demonstrated by scanning amperometric measurements of oxygen distribution above an Al-Cu-CFRP (Carbon Fiber Reinforced Polymer) galvanic corrosion cell.
Databáze:	MEDLINE
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