title: Non-destructive Patterning of Carbon Electrodes by Using the Direct Mode of Scanning Electrochemical Microscopy.
abstract: Patterning of glassy carbon surfaces grafted with a layer of nitrophenyl moieties was achieved by using the direct mode of scanning electrochemical microscopy (SECM) to locally reduce the nitro groups to hydroxylamine and amino functionalities. SECM and atomic force microscopy (AFM) revealed that potentiostatic pulses applied to the working electrode lead to local destruction of the glassy carbon surface, most likely caused by etchants generated at the positioned SECM tip used as the counter electrode. By applying galvanostatic pulses, and thus, limiting the current during structuring, corrosion of the carbon surface was substantially suppressed. After galvanostatic patterning, unambiguous proof of the formation of the anticipated amino moieties was possible by modulation of the pH value during the feedback mode of SECM imaging. This patterning strategy is suitable for the further bio-modification of microstructured surfaces. Alkaline phosphatase, as a model enzyme, was locally bound to the modified areas, thus showing that the technique can be used for the development of protein microarrays.
authors: Analytical Chemistry-Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany), Fax.
authors: Lutz
authors: L
authors: Stratmann
authors: Analytical Chemistry-Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany), Fax.
authors: Jan
authors: J
authors: Clausmeyer
authors: Analytical Chemistry-Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany), Fax. wolfgang.schuhmann@rub.de.
authors: Wolfgang
authors: http://orcid.org/0000-0003-2916-5223
authors: W
authors: Schuhmann
mesh_terms: D002244:Carbon / Q000737:chemistry*; D004566:Electrodes; D004579:Electron Transport; D005295:Ferrocyanides / Q000737:chemistry; D018625:Microscopy, Atomic Force; D064347:Microscopy, Electrochemical, Scanning; D009994:Osmolar Concentration
chemical_list: D005295:Ferrocyanides; C116383:ferrocyn; D002244:Carbon
keywords: diazonium salt grafting; electrodeposition; scanning electrochemical microscopy; scanning probe microscopy; surface patterning