Toward the Control of the Creation of Mixed Monolayers on Glassy Carbon Surfaces by Amine Oxidation

• Published in: Chemistry : a European journal Vol. 22; no. 3; pp. 1030 - 1036
• Main Authors: Groppi, Jessica, Bartlett, Philip N., Kilburn, Jeremy D.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 18.01.2016; Wiley; Wiley Subscription Services, Inc
• Subjects: Amines; Anthraquinone; Anthraquinones; Attachment; Carbon; Chemistry; Chemistry, Multidisciplinary; Coupling; Electrochemistry; Electrodes; Glassy carbon; Grafting; Joining; Methodology; Monolayers; Optimization; Osmium; Oxidation; Peptides; Physical Sciences; Probes; Protecting groups; Science & Technology; solid-phase synthesis; Voltammetry; GOLD; PHASE SYNTHESIS METHODOLOGIES; SELF-ASSEMBLED MONOLAYERS; electrochemistry; monolayers; amines; ORGANIC FILMS; osmium; solid-phase synthesis; MOLECULAR RULERS; ELECTROCHEMICAL OXIDATION; NORBORNYLOGOUS BRIDGES; ELECTRON-TRANSFER; COVALENT MODIFICATION; REDOX CENTERS
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201503120

A versatile and simple methodology for the creation of mixed monolayers on glassy carbon (GC) surfaces was developed, using an osmium–bipyridyl complex and anthraquinone as model redox probes. The work consisted in the electrochemical grafting on GC of a mixture of mono‐protected diamine linkers in varying ratios which, after attachment to the surface, allowed orthogonal deprotection. After optimisation of the deprotection conditions, it was possible to remove one of the protecting groups selectively, couple a suitable osmium complex and cap the residual free amines. The removal of the second protecting group allowed the coupling of anthraquinone. The characterisation of the resulting surfaces by cyclic voltammetry showed the variation of the surface coverage of the two redox centres in relation to the initial ratio of the linking amine in solution. A versatile and simple methodology for the creation of mixed monolayers at glassy carbon electrodes was developed using the electrochemical oxidation of primary amines and solid‐phase peptide synthesis techniques. An osmium–bipyridyl complex and anthraquinone were used as redox probes to quantify the variation of the relative coverage of two mono‐protected amine linkers at the electrode surface.