Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

Journal Article · Mon Aug 08 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4960734· OSTI ID:22594361

Palacio, F.; López, M. ^[1]; Pérez, J. ^[2]; Mir, M. ^[2]; Blázquez, O.; Hernández, S.; Garrido, B. ^[3]

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1. SIC, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)
2. Nanobioengineering Group, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, E-08028 Barcelona (Spain)
3. MIND-IN"2UB, Departament d'Enginyeries: Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)

The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than the geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.

• OSTI ID: 22594361
• Journal Information: Applied Physics Letters, Vol. 109, Issue 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
ATOMIC FORCE MICROSCOPY
COMPARATIVE EVALUATIONS
CRYSTALLIZATION
DEPOSITS
ELECTROCHEMISTRY
ELECTRODES
ELECTRON BEAMS
ELECTRONS
EPOXIDES
INDIUM OXIDES
MOLECULES
MORPHOLOGY
NANOWIRES
SCANNING ELECTRON MICROSCOPY
SILANES
SURFACE AREA
SURFACES
THIN FILMS
TIN OXIDES