Integration of ion-tuned oligonucleotide structural motifs and DNA-templated copper nanoclusters as a manipulable logic device

Abstract Molecular logic gates possess great potential for multi-parameter sensing, intelligent diagnostics, and molecular computation. One remaining challenge was to construct novel new logic gates based on smart nanomaterials and functional nucleic acids. In this study, two novel new logic devices were constructed utilizing ion-tuned DNA/copper nanoclusters (CuNCs), which were dual-responsive to K+ and H+. By merely altering the arrangement of a specific sequence of the DNA stabilizer, two kinds of well-designed DNA probes permuted by G-tracts, C-tracts, and poly-T were designed as the building blocks of the logic device. Poly-T acted as the template for the formation of CuNCs. G-tracts and C-tracts enabled a K+/H+-responsive conformational switch into G-quadruplex (G4) and i-motif structures. Such a conformational conversion significantly modulated the fluorescence behaviors of CuNCs. This study discovered the unique interaction between the logic device and graphene oxide (GO). The logic devices were implemented for the analysis of K+ and microRNA.