Controlling interfacial electron transfer and electrocatalysis by pH- or ion-switchable DNA monolayer-modified electrodes

Gilad Pelossof, Ran Tel-Vered, Simcha Shimron, Itamar Willner*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

pH-stimulated formation and dissociation of i-motif DNA nanostructures associated with electrodes lead to the control of interfacial electron transfer resistances in the presence of Fe(CN)63−/4− as a redox label (measured by Faradaic impedance spectroscopy). While at neutral pH (pH = 7.0), the interfacial electron transfer resistance is high, R et 500 ω, in the presence of the i-motif nanostructure (pH = 5.8) it decreases to R et 300 ω. By cycling the pH of the solution between the values 7.0 and 5.8, the electron transfer resistances are reversibly switched between high and low values, respectively. The switchable charge transport at the modified electrode is rationalized in terms of the electrostatic interactions between the modified electrode and the redox label. Similarly, the generation of a G-quadruplex through the formation of an aptamer-AMP complex leads to the control of the interfacial electron transfer resistance. The i-motif- or G-quadruplex-controlled electron transfer resistances are implemented to yield the switchable electrocatalyzed reduction of H2O2 in the presence of negatively charged, citrate-stabilized, Ag nanoparticles.

Original languageEnglish
Pages (from-to)1137-1144
Number of pages8
JournalChemical Science
Volume4
Issue number3
DOIs
StatePublished - 4 Feb 2013

Fingerprint

Dive into the research topics of 'Controlling interfacial electron transfer and electrocatalysis by pH- or ion-switchable DNA monolayer-modified electrodes'. Together they form a unique fingerprint.

Cite this