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Electrostatic-Gated Transport in Chemically Modified Glass Nanopore Electrodes
- Source :
- Journal of the American Chemical Society. 128:7679-7686
- Publication Year :
- 2006
- Publisher :
- American Chemical Society (ACS), 2006.
-
Abstract
- Electrostatic-gated transport in chemically modified glass nanopore electrodes with orifice radii as small as 15 nm is reported. A single conical-shaped nanopore in glass, with a approximately 1 microm radius Pt disk located at the pore base, is prepared by etching the exposed surface of a glass-sealed Pt nanodisk. The electrochemical response of the nanopore electrode corresponds to diffusion of redox-active species through the nanopore orifice to the Pt microdisk. Silanization of the exterior glass surface with Cl(Me)(2)Si(CH(2))(3)CN and the interior pore surface with EtO(Me)(2)Si(CH(2))(3)NH(2) introduces pH-dependent ion selectivity at the pore orifice, a consequence of the electrostatic interactions between the redox ions and protonated surface amines. Nanopore electrodes with very small pore orifice radii (approximately 50 nm) display anion permselectively at pH4, as demonstrated by electrochemical measurement of transport through the pore orifice. Ion selective transport vanishes at pH6 or when the pore radius is significantly larger than the Debye screening length, consistent with the observed ion selectivity resulting from electrostatic interactions. The ability to introduce different surface functionalities to the interior and exterior surfaces of glass nanopores is demonstrated using fluorescence microscopy to monitor the localized covalent attachment of 5- (and 6)-carboxytetramethylrhodamine succinimidyl ester to interior pore surfaces previously silanized with EtO(Me)(2)Si(CH(2))(3)NH(2).
- Subjects :
- Surface Properties
Static Electricity
Analytical chemistry
Biosensing Techniques
Electrochemistry
Biochemistry
Catalysis
Colloid and Surface Chemistry
Etching (microfabrication)
Platinum
Chemistry
General Chemistry
Hydrogen-Ion Concentration
Silanes
Electrostatics
Nanostructures
Nanopore
Microscopy, Fluorescence
Silanization
Electrode
Glass
Cyclic voltammetry
Microelectrodes
Oxidation-Reduction
Porosity
Body orifice
Subjects
Details
- ISSN :
- 15205126 and 00027863
- Volume :
- 128
- Database :
- OpenAIRE
- Journal :
- Journal of the American Chemical Society
- Accession number :
- edsair.doi.dedup.....feb8b305227530e6031bcab58e1a203f