Functional DNA structures for cytosensing

Cells contain various biological molecules. Detection or imaging of these biomolecules in situ or the cells themselves, which is defined as cytosensing, is an important issue in life science. Cytosensing usually needs functional molecule tools to proceed the recognition of targets, and signal readout. DNA is a kind of powerful tools, which possess advantages of easy accessibility, controllable structural diversity, and excellent biocompatibility. In recent years, functional DNA structures have been widely applied in cytosensing, which have made great progresses in life mechanism-related research at cell level. In this review, we firstly introduce the functional DNA structures developed in recent years and their structure characteristics, including DNA aptamers, DNAzymes, DNA-nanoparticle conjugates, amplifiable DNA assemblies, and three-dimensional DNA complex structures. Then, we summarize and evaluate the application of functional DNA structures in different scenes, such as detection of biological molecules, tumor imaging and therapy, profiles of cellular physics properties and interactions, and super-resolution imaging, followed by discussion and outlook of the future challenges in this field. This review will provide a valuable guidance for researchers to create new functional DNA tools and promote the development of cytosensing to reveal more life mechanisms. •The recent applications of functional DNA structures in cytosensing are summarized.•The cytosensing strategies based on DNA structures are introduced.•The cytosensing cases using functional DNA structures in different fields are described.•The challenges and development tendency of functional DNA structures for cytosensing are discussed.