Here we report a novel method to form a pseudorotaxane architecture using only a pair of reactive oligodeoxyribonucleotides (ODNs), which we designed and synthesized, and then performed the pseudorotaxane formation reaction with both DNA and RNA oligonucleotides. The reaction proceeded smoothly without any extra reagents at 37 °C and pH 7.2, leading to the formation of a stable complex on a denaturing polyacrylamide gel. Interestingly, the pseudorotaxane was formed with the cyclized ODN reversibly by the slipping process. This new pseudorotaxane formation represents a promising method for developing new DNA nanotechnologies and antisense oligonucleotides.

A series of triphenylphosphinecarboxamide (TPPc) derivatives were designed and synthesized as alternative reagents to triphenylphosphine for the facile reduction of azides. The TPPc derivatives performed as efficient reducing agents for the synthesis of primary amines without the need for an additional hydrolysis procedure. The TPPc derivatives were also applied to nucleic acid sensing using a RhAz-oligonucleotide conjugate in a DNA-templated fluorogenic reaction.

Protein nanotubes formed by layer-by-layer (LbL) assembly can penetrate cells and act as nanopores for direct transmembrane delivery of chemical compounds.

Oligonucleotide-templated reactions are powerful tools for the detection of nucleic acid sequences. One of the major scientific challenges associated with this technique is the rational design of non-enzyme-mediated catalytic templated reactions capable of multiple turnovers that provide high levels of signal amplification. Herein, we report the development of a nucleophilic aromatic substitution reaction-triggered fluorescent probe. The probe underwent a rapid templated reaction without any of the undesired background reactions. The fluorogenic reaction conducted in the presence of a template provided a 223-fold increase in fluorescence after 30 s compared with the nontemplated reaction. The probe provided an efficient level of signal amplification that ultimately enabled particularly sensitive levels of detection. Assuming a simple model for the templated reactions, it was possible to estimate the rate constants of the chemical reaction in the presence and in the absence of the template. From these kinetic analyses, it was possible to confirm that an efficient turnover cycle had been achieved, on the basis of the dramatic enhancement in the rate of the chemical reaction considered to be the rate-determining step. With maximized turnover efficiency, it was demonstrated that the probe could offer a high turnover number of 1500 times to enable sensitive levels of detection with a detection limit of 0.5 pM in the catalytic templated reactions.

A pre-type sensitizer for a lanthanide complex on an oligonucleotide was successfully converted to a perfect final structure in a target DNA/RNA-templated reaction, without any chemical reagent or enzyme, under neutral conditions. The final form of the lanthanide–oligonucleotide provided a long-lived luminescence signal, appropriate for time-gated luminescence analysis and signal amplification. Target DNA/RNA-assisted time-gated luminescence analysis is a powerful tool for elimination of autofluorescence and detection of target RNA in living bacterial cells.

We have synthesized a series of 4-substituted-2-nitrobenzene-sulfonyl compounds for caged fluorogenic probes and conducted a Hammett plot analysis using the steady-state kinetic parameters. The results revealed that the glutathione transferase (GST) alpha catalyzed reaction was dependent on the σ value in the same way as the non-enzymatic reaction, whereas the dependence of the σ value of the GST mu and pi was not as pronounced as that of GST alpha.

Protein nanotubes formed by layer-by-layer (LbL) assembly can penetrate cells and act as nanopores for direct transmembrane delivery of chemical compounds.