Consecutive Silver(I) Ion Incorporation into Oligonucleotides containing Cytosine‐Cytosine Mispairs

Abstract Herein, the consecutive incorporation of Ag I ion into the dsDNA containing adjacent C−C mispairs is demonstrated. The melting temperature (T m ) was 8 ° C higher for DNA containing three C−C mispairs upon the addition of three Ag I ions as compared to the Ag I ‐free DNA, and no T m was obtained in the presence of excess Ag I ion, indicating a stable bridging of C‐Ag I −C upon the incorporation of the stoichiometric amount of Ag I per C−C mispair. The circular dichroism (CD) spectra of the dsDNA showed a negative peak at ∼270 nm in the presence of excess Ag I , implying that significant structural changes and a potential aggregation of DNA occurred. Subsequently, the Ag I ‐mediated DNA strands are immobilized on Au surfaces. Their electrochemical properties are monitored using CV, EIS and SECM showing increased overpotentials and charge‐transfer resistances, and decreased the rate constant in the presence of an excess of Ag I , respectively. These results are further supported by the XPS and sulfide‐Au reductive desorption measurements.