Carbon materials are widely used for modified electrodes in electroanalysis and in particular the recent development of a new range of nanocarbons has triggered many new developments in electrochemical sensing. In this report uniform carbon nanoparticles are employed in conjunction with a poly(diallyldimethylammonium chloride) or PDDAC binder. After suspension into water, the carbon nanoparticles with negative surface charge readily assemble onto surfaces which have been modified with PDDAC polycations. A layer-by-layer electrostatic assembly process is used to grow thin carbon nanoparticle films with ca. 5 to 6 nm average thickness increase per deposition layer at tin-doped indium oxide (ITO) substrates. Transparent and strongly adhering films of high electrical conductivity are formed and characterized in terms of their electrochemical reactivity. When immersed in aqueous 0.1 M phosphate buffer pH 7, each layer of CNP-PDDAC is adding an interfacial capacitance of ca. 10 mF cm^-2. Absorption into the CNP–PDDAC nanocomposite film is dominated by the sites in the PDDAC cationomer and therefore anionic molecules such as indigo carmine are strongly bound and retained within the film (cationic binding sites per layer ca. 150 pmol cm^-2). The characteristics of these ultrathin films as electrodes for adsorbed and for solution redox systems are explored and the selective determination of dopamine in the presence of ascorbate is highlighted as a potential sensor application. The determination of dopamine in the presence of ascorbateis a challenging problem for in vivo nerve cell investigations and it has led to new types of modified electrodes. For the mixed redox system ascorbate–dopamine in 0.1M phosphate buffer pH 7 cyclic voltammograms suggest a rapid and selective temporary poisoning process which causes the ascorbate oxidation to be suppressed in the second potential cycle. This effect is exploited for the detection of micromolar concentrations of dopamine in the presence of millimolar ascorbate.

References

[1] K.J. McKenzie, F. Marken, Langmuir 19 (2003) 4327.

 [2] R. L. McCreery, Electroanal. Chem. 1991, 17, 221.

 [3] C.W. Welch, R. G. Compton, Anal. Bioanal. Chem. 2006, 384, 601.

[4] G. Decher, J. B. Schlenoff, Multilayer Thin Films, Wiley VCH, Weinheim 2003.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/12737 must be provided.

1. Impedance Methods in Electrochemistry
2. Redox Reactivity of Methylene Blue in the Pores of UMCM-1 Metal-Organic Frameworks
3. Carbon Nanoparticle Surface Modification for Sensor Development
4. Ion Association Effects in Cellulose – Poly-(Diallyldimethylammonium) Reassembled Membranes Immersed in Acetonitrile
5. Conduction in Nanoparticle Assemblies and Mesoporous Films
6. Positively Charged Surface Functionalised Carbon Nanoparticles as Binding Sites for Redox Active Species
7. Triple Phase Boundary Photo-Voltammetry: Resolving Rhodamine B Reactivity in 4-(3-Phenylpropyl)-Pyridine Microdroplets
8. Carbon Dioxide Sensing Systems Based On Processes At Triple Phase Boundary Interfaces
9. Electrochemical behaviour of carbonised cellulose nanofibril films on the ITO electrode surface
10. MoSe₂ Substrates for the Electrodeposition of CISe Semiconductor Films
11. Silver Nanoparticle Catalysed NO₃^- Reduction Characterised with a Hydrodynamic Generator-Collector SPCE System
12. Driving ion transfer across the toluene (trihexyl(tetradecyl)-phosphonium tris(pentafluoroethyl)trifluoro-phosphate) | water (electrolyte) interface with the MnTPP(III/II) redox system
13. Electrocatalytic Sulphite Detection at a Liquid-Liquid-Solid Three-Phase Boundary Electrode Sensors
14. Electrochemical Processes at Electrodes in Microwave Fields
15. Liquid-Liquid Ion-Transfer Electrochemistry at Stationary and at Flowing Triple Phase Boundaries
16. Microwave-assisted Capillary Electrophoresis with Electrochemical Detection
17. Analysis of Chlorobenzenes in Environmental Water Samples using Microwave-Assisted with Ionic-Liquids Liquid-Phase Microextraction
18. Electrochemical reactivity of proteins immobilised in mesoporous titania
19. New electrode surfaces for solid | liquid | liquid triple phase boundary electrochemistry
20. Ion transfer electrodes based on carbon nanofibers embedded in silicate film modified with room temperature ionic liquid
21. Nanoobjects embedded in silicate films for biphasic electrodes
22. Electrochemical Processes in Mesoporous TiO₂ Phytate Films