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RESEARCH PRODUCT
Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.
Patricio RamirezWolfgang EnsingerJavier CerveraSalvador MafeHung Quoc NguyenSaima NasirMubarak Alisubject
NanoporeRe-configurablePHAmino acid chainsEtching timeElectrical signalCarboxylic AcidsGeneral Physics and AstronomyFunctionalizationsElectrolytePore surfaceElectrochemistryFunctionalizedCarboxylic acidOptical imageNanoporesElectric conductivityI - V curveElectrochemistryGeneral Materials ScienceTheoretical modelRectifying behaviorsFundamental conceptsRectifying propertiesSurface propertyGeneral EngineeringHydrogen-Ion ConcentrationCigar-shaped nanoporeCharacterization (materials science)Data processingChemistryNanoporeAmino acidsIon channelTransport simulationIodineLogic functionsNanostructureMaterials scienceLogicSurface PropertiesCharacterizationNanotechnologyTunabilitiesArticleDrug controlled releaseElectrical resistivity and conductivityEtchingTransport processPH-responsiveCurrent voltage curveDiodeChemical proceduresCarboxylic acidsLysineElectric ConductivityModels TheoreticalGeometrical opticsNanostructuresAmphoteric amino acid chainsCurrent-voltage curvesExternal solutionsFISICA APLICADAElectrolyte concentrationdescription
We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurable diode showing different rectifying behaviors by applying chemical and electrical signals. The remarkable characteristics of the new nanopore are the sharp response observed in the I-V curves, the improved tunability (with respect to previous designs of symmetric nanopores) which is achieved because of the direct external access to the nanostructure mouths, and the broad range of rectifying properties. The results concern both fundamental concepts useful for the understanding of transport processes in biological systems (ion channels) and applications relevant for tunable nanopore technology (information processing and drug controlled release). © 2012 American Chemical Society.
year | journal | country | edition | language |
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2012-01-01 | ACS nano |