Recent progress in abasic site-binding small molecules for detecting single-base mutations in DNA

This review addresses our recent efforts to design AP site-binding small ligands for SNP (single-nucleotide polymorphisms) typing. First, we present a surface plasmon resonance (SPR) biosensor carrying a derivative of 3,5-diaminopyrazines. Comparison with a bulk assay based on 3,5-diaminopyrazines-DNA binding shows that the immobilization of 3,5-diaminopyrazines on the SPR sensor allows a more sensitive detection of the target DNA, and binding selectivity can be tuned by controlling salt concentrations of the sample solutions. We also present a ratiometric fluorescent probe, in which an environmentally sensitive fluorescent dye, a benzofurazan derivative, is linked through an alkyl spacer to a 2-amino-1,8-naphthyridine derivative. The binding and sensing properties of these systems are discussed as a basis for the advanced design of DNA-binding small molecules for gene detection.