Creation of Quasi‐DNA Origami at the Air/Water Interface Using the Collapsed Mechanism of Langmuir Monolayer

Abstract

AbstractIt has achieved the preparation of quasi‐deoxyribonucleic acid (DNA) origami using the techniques of organized molecular films. After the adsorption of DNA from the subphase onto a Langmuir monolayer of polymers containing diamino‐s‐triazine rings, the monolayer collapses owing to high surface pressure, resulting in the formation of a three‐dimensional folded structure of DNA. A homopolymer featuring a diamino‐s‐triazine ring and a copolymer containing 20 % long alkyl chains are used to form the Langmuir monolayer. A‐T base pairs of salmon testis‐derived DNA from the subphase are hydrogen‐bonded and adsorbed onto each Langmuir monolayer. Following the collapse of the Langmuir monolayer, the film height almost doubles, indicating the formation of a bilayer structure consisting of a bioadsorbed polymer monolayer, especially evident in copolymer‐collapsed films. During this period, the bioconjugated bilayer structure adopts a mesoscopic linear morphology within the plane. In this quasi‐DNA origami structure, the chirality in the DNA molecule is maintained, as evidenced by the circular dichroism (CD) spectra displaying a positive Cotton effect. These results correspond to the proposal of a new DNA morphology control technology.