An Aptamer-Mediated DNA Nano-Switch

Abstract

The programmability of DNA has multiple applications including diagnosis, drug delivery and bioelectronics. Recent designs of responsive DNA nanostructure could detect the presence of different nucleic acid targets and other molecules through strand displacement as an indirect method. We have developed the DNA nanotweezers triggered by the presence of Plasmodium falciparum lactate dehydrogenase (PfLDH). The closure of nanotweezers will result in the formation of G-quadruplex catalyzing the peroxidase activity of hemin as a colorimetric signal. We also applied the same aptamer to a DNA origami box and used PfLDH as a key to open it. The observations from transmission electron microscopy and fluorescence resonance energy transfer indicated that the opening can be achieved in three hours and it is highly specific towards PfLDH. The success in using protein specific aptamer to control the structural change of DNA nanostructure indicates the potential of developing more diversified diagnostic and drug delivery systems.