this study, we report the synthesis of modified oligonucleotides consisting of benzoic acid or isophthalic acid residues as new nucleobases. As evaluated by UV thermal denaturation analysis at different pH conditions (5.0, 6.0, 7.0, and 8.0), these modified oligonucleotides exhibited pH-dependent recognition of natural nucleobases and one is first found to be capable of basepair switching in response
Excitonic interaction was utilized to design a highlysensitive in‐stem molecularbeacon (ISMB) in which both a fluorophore and a quencher on D‐threoninols are incorporated as a pseudo base pair (see scheme; optimized combination with Cy3 and modified Methyl Red). Minimization of the difference between λmax of the fluorophore and quencher maximized quenching efficiency.