Читать книгу DNA Origami - Группа авторов - Страница 70

This chapter provided an overview of how time‐lapse AFM techniques have been applied to study mechanically functional DNA origami nanodevices and 2D self‐assembly of DNA origami arrays. Most nanodevices introduced here are designed to respond ions and photostimuli. In addition to the development of these stimuli‐responsive DNA origami structures, attempts to drive DNA nanodevices by electric [73, 74] or magnetic fields [75] are also progressing. Many of these devices are composed of a stator part that is fixed onto a glass surface and a movable arm whose orientation or angle against the stator is controlled by electric or magnetic fields. Rotational or hinge‐like movements of arms are generally monitored using a single‐molecule fluorescence imaging technique, such as a total internal reflection fluorescence (TIRF) microscopy. However, the observed behavior of the fluorescent spot does not always provide direct information on how the entire single nanodevices actually behave. Therefore, the next advancement of this technology would grow out of the integration of HS‐AFM and fluorescence imaging techniques. This direction has now progressed from possibility to actuality thanks to the emergence of HS‐AFM combined with various fluorescence microscopies, such as inverted fluorescence microscopy [76], confocal laser scanning microscopy [77], and TIRF microscopy [78]. It is hoped that both structural changes in individual nanodevices or morphological changes of self‐assembly systems will be correlated with nano‐to‐meso scale dynamics of their components. The combination of HS‐AFM with microfluidic devices and those that exploit electric magnetic manipulation is also a fascinating means of applying designated external stimuli with computer‐controlled arbitrary timing. In the not‐so‐distant future, we will be able to arbitrarily manipulate DNA nanodevices and specific components in the assembled structures, while directly seeing their real‐time structural or spatial changes at nanoscale resolution.