Self-assembly of DNA walker with biosensing application assisted by chemoselective ligation

In this paper, we report chemoselective ligation-assisted self-assembly of DNA walker. Specifically, three kinds of chemoselective ligations including azide-alkyne cycloaddition, oxime ligation, and hydrazone ligation, have been proposed to mediate the self-assembly of DNA walker and to induce the following operation. Then, we present our design that the walking strand of the DNA walker is splitted as action strand and supporting strand, which are separately modified by the pair of the chemoselective linkage groups. Therefore, combined with the supporting strand, the action strand can activate the DNA walker, which can be further developed as a biosensor for the analysis of different kinds of biomolecules such as polysaccharide, protein, and nucleic acid. Taking lipopolysaccharide, thrombin, and Let-7a as examples, the fabricated biosensors based on chemoselective ligation-assisted DNA walkers all exhibit high sensitivity and accuracy in view of the great advantages of chemoselective ligation. This work may provide an insight for covalent bond adjusted molecular self-assembly and the development of biosensor based on the construction of DNA walker.