DNA hydrogel is a promising biomaterial for biological and medical applications due to its native biocompatibility and biodegradability. Herein, we provide a novel, versatile, and cost-effective approach for self-assembly of DNA hydrogel using the enzymatically polymerized DNA building blocks. The X-shaped DNA motif was elongated by terminal deoxynucleotidyl transferase (TdT) to form the building blocks, and hybridization between dual building blocks via their complementary TdT-polymerized DNA tails led to gel formation. TdT polymerization dramatically reduced the required amount of original DNA motifs, and the hybridization-mediated cross-linking of building blocks endows the gel with high mechanical strength. The DNA hydrogel can be applied for encapsulation and controllable release of protein cargos (for instance, green fluorescent protein) due to its enzymatic responsive properties. Moreover, this versatile strategy was extended to construct a functional DNAzyme hydrogel by integrating the peroxidase-mimicking DNAzyme into DNA motifs. Furthermore, a hybrid cascade enzymatic reaction system was constructed by coencapsulating glucose oxidase and β-galactosidase into DNAzyme hydrogel. This efficient cascade reaction provides not only a potential method for glucose/lactose detection by naked eye but also a promising modular platform for constructing a multiple enzyme or enzyme/DNAzyme hybrid system.

Integrating multiple components of a logic device into a 3D DNA nanoprism provides a universal platform for constructing diverse logic gates.

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Protein phosphorylation catalyzed by protein kinase is one of the most ubiquitous and important post-translational modification and aberrant phosphorylation is closely related with a variety of human diseases, especially cancer. As the critical component of intracellular signal pathways, protein kinases are involved in regulating a number of important physiological processes, such as cell growth, metabolism, differentiation, and proliferation. Therefore, developing potent and specific analytical methods of protein kinases are of great significance for biochemical fundamental research, disease diagnosis and treatment, and drug development. In recent years, the growing number of functional nanomaterials have been exploited in the development of protein kinase biosensors. Due to their unique optical, electrical, chemical, and catalytic properties, nanomaterials play crucial roles in several key processes in bio-sensing, such as signal generation and transduction, biosensing interface fabrication, as well as biochemical signal amplification, which greatly improves the analytical performance of kinase biosensors. This paper briefly summarizes the generally used molecular recognition mechanisms of kinase detections, then gives a systematic overview of the nanomaterials-based protein kinases assays classified by the different analytical techniques. Consequently, the future development of protein kinase biosensors is prospected.