Electrochemically stimulated pH changes: A route to control chemical reactivity

Marco Frasconi, Ran Tel-Vered, Johann Elbaz, Itamar Willner

Research output: Contribution to journalArticlepeer-review


A bis-aniline-cross-linked Au nanoparticle (NP) composite is electrochemically prepared on a rough Pt film supported on a Au electrode. The electrochemical oxidation of the bis-aniline units to the quinoid state releases protons to the electrolyte solution, while the reduction of the quinoid bridges results in the uptake of protons from the electrolyte. By the cyclic oxidation of the bridging units (E = 0.25 V vs SCE), and their reduction (E = -0.05 V vs SCE), the pH of the solution could be reversibly switched between the values 5.8 and 7.2, respectively. The extent of the pH change is controlled by the number of electropolymerization cycles applied to synthesize the Au NP composite, demonstrating a ca. 1.5 pH units change by a matrix synthesized using 100 electropolymerization cycles. The pH changes are used to reversibly activate and deactivate a C-quadruplex (i-motif)-bridged Mg2+-dependent DNAzyme.

Original languageEnglish
Pages (from-to)2029-2036
Number of pages8
JournalJournal of the American Chemical Society
Issue number6
StatePublished - 2010
Externally publishedYes


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