DNA is traditionally known as a central genetic biomolecule in living systems. From an alternative perspective, DNA is a versatile molecular building-block for the construction of functional materials, in particular biomaterials, due to its intrinsic biological attributes, molecular recognition capability, sequence programmability, and biocompatibility. The topologies of DNA building-blocks mainly include linear, circular, and branched types. Branched DNA recently has been extensively employed as a versatile building-block to synthesize new biomaterials, and an assortment of promising applications have been explored. In this review, we discuss the progress on DNA functional materials assembled from branched DNA. We first briefly introduce the background information on DNA molecules and sketch the development history of DNA functional materials constructed from branched DNA. In the second part, the synthetic strategies of branched DNA as building-blocks are categorized into base-pairing assembly and chemical bonding. In the third part, construction strategies for the branched DNA-based functional materials are comprehensively summarized including tile-mediated assembly, DNA origami, dynamic assembly, and hybrid assembly. In the fourth part, applications including diagnostics, protein engineering, drug and gene delivery, therapeutics, and cell engineering are demonstrated. In the end, an insight into the challenges and future perspectives is provided. We envision that branched DNA functional materials can not only enrich the DNA nanotechnology by ingenious design and synthesis but also promote the development of interdisciplinary fields in chemistry, biology, medicine, and engineering, ultimately addressing the growing demands on biological and medical-related applications in the real world.

DNA Functional Materials Assembled from Branched DNA: Design, Synthesis, and Applications.

Development of biosensing platforms plays a key role in research settings for identification of biomarkers and in clinical applications for diagnostics. Biosensors based on nucleic acids have taken many forms, from simple duplex-based constructs to stimuli-responsive nucleic acid nanostructures. In this review, we look at various nucleic acid-based biosensors, the different read-out strategies employed, and their use in chemical and biological sensing. We also look at current developments in DNA nanotechnology-based biosensors and how rational design of such constructs leads to more efficient biosensing platforms.

Rationally Engineered Nucleic Acid Architectures for Biosensing Applications.

One-pot in-situ hydrothermal synthesis of ternary In2S3/Nb2O5/Nb2C Schottky/S-scheme integrated heterojunction for efficient photocatalytic hydrogen production.

Design strategy for MXene and metal chalcogenides/oxides hybrids for supercapacitors, secondary batteries and electro/photocatalysis

Electrochemical water splitting represents one of the most promising technologies to produce green hydrogen, which can help to realize the goal of achieving carbon neutrality. While substantial efforts on a laboratory scale have been made for understanding fundamental catalysis and developing high-performance electrocatalysts for the two half-reactions involved in water electrocatalysis, much less attention has been paid to doing relevant research on a larger scale. For example, few such researches have been done on an industrial scale. Herein, we review the very recent endeavors to bridge the gaps between fundamental research and industrial applications for water electrolysis. We begin by introducing the fundamentals of electrochemical water splitting and then present comparisons of testing protocol, figure of merit, catalyst of interest, and manufacturing cost for laboratory and industry-based water-electrolysis research. Special attention is paid to tracking the surface reconstruction process and identifying real catalytic species under different testing conditions, which highlight the significant distinctions of corresponding electrochemical reconstruction mechanisms. Advances in catalyst designs for industry-relevant water electrolysis are also summarized, which reveal the progress of moving the practical applications forward and accelerating synergies between material science and engineering. Perspectives and challenges of electrocatalyst design strategies are proposed finally to further bridge the gaps between lab-scale research and large-scale electrocatalysis applications. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/eem2.12441

Electrochemical Water Splitting: Bridging the Gaps between Fundamental Research and Industrial Applications

Ruthenium (Ru)‐based electrocatalysts as platinum (Pt) alternatives in catalyzing hydrogen evolution reaction (HER) are promising. However, achieving efficient reaction processes on Ru catalysts is still a challenge, especially in alkaline media. Here, the well‐dispersed Ru nanoparticles with adjacent Ru single atoms on carbon substrate (Ru1,n‐NC) is demonstrated to be a superb electrocatalyst for alkaline HER. The obtained Ru1,n‐NC exhibits ultralow overpotential (14.8 mV) and high turnover frequency (1.25 H2 s‐1 at −0.025 V vs reversible hydrogen electrode), much better than the commercial 40 wt.% Pt/C. The analyses reveal that Ru nanoparticles and single sites can promote each other to deliver electrons to the carbon substrate. Eventually, the electronic regulations bring accelerated water dissociation and reduced energy barriers of hydroxide/hydrogen desorption on adjacent Ru sites, then an optimized reaction kinetics for Ru1,n‐NC is obtained to achieve superb hydrogen generation in alkaline media. This work provides a new insight into the catalyst design in simultaneous optimizations of the elementary steps to obtain ideal HER performance in alkaline media.

Synergic Reaction Kinetics over Adjacent Ruthenium Sites for Superb Hydrogen Generation in Alkaline Media

DNA tensegrity triangles self-assemble into rhombohedral three-dimensional crystals via sticky ended cohesion. Crystals containing two-nucleotide (nt) sticky ends (GA:TC) have been reported previously, and those crystals diffracted to 4.9 A at beamline NSLS-I-X25. Here, we analyze the effect of varying sticky end lengths and sequences as well as the impact of 5'- and 3'-phosphates on crystal formation and resolution. Tensegrity triangle motifs having 1-, 2-, 3-, and 4-nt sticky ends all form crystals. X-ray diffraction data from the same beamline reveal that the crystal resolution for a 1-nt sticky end (G:C) and a 3-nt sticky end (GAT:ATC) were 3.4 and 4.2 A, respectively. Resolutions were determined from complete data sets in each case. We also conducted trials that examined every possible combination of 1-nucleotide and 2-nucleotide sticky-ended phosphorylated strands and successfully crystallized all 16 possible combinations of strands. We observed the position of the 5'-phosphate on either the crossover (1), helical (2), or central strand (3) affected the resolution of the self-assembled crystals for the 2-turn monomer (3.0 A for 1-2P-3P) and 2-turn dimer sticky ended (4.1 A for 1-2-3P) systems. We have also examined the impact of the identity of the base flanking the sticky ends as well as the use of 3'-phosphate. We conclude that crystal resolution is not a simple consequence of the thermodynamics of the direct nucleotide pairing interactions involved in molecular cohesion in this system.

/pdf/designing-higher-resolution-self-assembled-3d-dna-crystals-35fg1741tr.pdf

Designing Higher Resolution Self-Assembled 3D DNA Crystals via Strand Terminus Modifications

Titanium carbide MXenes coupled with cadmium sulfide nanosheets as two-dimensional/two-dimensional heterostructures for photocatalytic hydrogen production.

Structural reconstruction is a process commonly observed for Cu‐based catalysts in electrochemical CO2 reduction. The Cu‐based precatalysts with structural complexity often undergo sophisticated structural reconstruction processes, which may offer opportunities for enhancing the electrosynthesis of multicarbon products (C2+ products) but remain largely uncertain due to various new structural features possibly arising during the processes. In this work, the Cu2O superparticles with an assembly structure are demonstrated to undergo complicated structure evolution under electrochemical reduction condition, enabling highly selective CO2‐to‐C2+ products conversion in electrocatalysis. As revealed by electron microscopic characterization together with in situ X‐ray absorption spectroscopy and Raman spectroscopy, the building blocks inside the superparticle fuse to generate numerous grain boundaries while those in the outer shell detach to form nanogap structures that can efficiently confine OH− to induce high local pH. Such a combination of unique structural features with local reaction environment offers two important factors for facilitating C−C coupling. Consequently, the Cu2O superparticle‐derived catalyst achieves high faradaic efficiencies of 53.2% for C2H4 and 74.2% for C2+ products, surpassing the performance of geometrically simpler Cu2O cube‐derived catalyst and most reported Cu electrocatalysts under comparable conditions. This work provides insights for rationally designing highly selective CO2 reduction electrocatalysts by controlling structural reconstruction.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/advs.202105292

Xinyu Wang

Papers

Synergic Reaction Kinetics over Adjacent Ruthenium Sites for Superb Hydrogen Generation in Alkaline Media

Designing Higher Resolution Self-Assembled 3D DNA Crystals via Strand Terminus Modifications

Titanium carbide MXenes coupled with cadmium sulfide nanosheets as two-dimensional/two-dimensional heterostructures for photocatalytic hydrogen production.

Structural Reconstruction of Cu2O Superparticles toward Electrocatalytic CO2 Reduction with High C2+ Products Selectivity

Silver based single atom catalyst with heteroatom coordination environment as high performance oxygen reduction reaction catalyst