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According to the demands of the Internet of Things (IoTs), a gas sensor is demanded to be small, portable, and easy to integrate with the environment or structure in its application. Herein, an ingenious form of in situ photoenergy gas sensor integrated with a deep ultraviolet light-emitting diode (LED) has been designed to achieve ppb level NO2 gas detection at room temperature. In this gas sensor, the deep ultraviolet LED based on AlGaN materials, which has a wider band gap and higher photoexcitation energy, acts as the substrate with emission at 280 nm. The ZnO nanorods of the gas-sensing material were directly grown on 2 inch AlGaN-based LEDs containing thousands of independent light-emitting chips, leading to photosensitive materials with uniform and controllable, as well as a sensor with low power consumption and mass manufacture with low cost. The result shows that responses of over 500% to 500 ppb of NO2 were observed by in situ irradiation of just 3 mW optical power. Meanwhile, sensitivity without real-time photoenergy is defined as the ratio of the resistance change rate in pollutant to that in air has been presented. Interestingly, the prototype gets in situ photoenergy charge for 5 min and then has responses of over 200% to 500 ppb of NO2 for 5 days in the dark. It may open a new avenue for the integrated microchip design of a gas sensor and give a novel sight into the sensitivity study without real-time assisted energy.

Transition-metal-catalyzed chlorosulfonylation of 5-ethynylpyrimidine nucleosides provided (E)-5-(β-chlorovinyl)sulfones A, which undergo nucleophilic substitution with amines or thiols affording B. The treatment of vinyl sulfones A with ammonia followed by acid-catalyzed hydrolysis of the intermediary β-sulfonylvinylamines gave 5-(β-keto)sulfones C. The latter reacts with electrophiles, yielding α-carbon-alkylated or -sulfanylated analogues D. The 5'-triphosphates of A and C were incorporated into double-stranded DNA, using open and one-nucleotide gap substrates, by human or Escherichia coli DNA-polymerase-catalyzed reactions.

The development of future sustainable energy technologies relies critically on our understanding of electrocatalytic reactions occurring at the electrode–electrolyte interfaces, and the identification of key reaction promoters and inhibitors. Here we present a systematic in situ nanoelectronic measurement of anionic surface adsorptions (sulfates, halides, and cyanides) on ultrathin platinum nanowires during active electrochemical processes, probing their competitive adsorption behavior with oxygenated species and correlating them to the electrokinetics of the oxygen reduction reaction (ORR). The competitive anionic adsorption features obtained from our studies provide fundamental insight into the surface poisoning of Pt-catalyzed ORR kinetics by various anionic species. Particularly, the unique nanoelectronic approach enables highly sensitive characterization of anionic adsorption and opens an efficient pathway to address the practical poisoning issue (at trace level contaminations) from a fundamental perspective. Through the identified nanoelectronic indicators, we further demonstrate that rationally designed competitive anionic adsorption may provide improved poisoning resistance, leading to performance (activity and lifetime) enhancement of energy conversion devices., We exploit an on-chip electrical transport spectroscopy to probe the competitive anionic adsorption at the electrochemical interface and to develop important insights into catalyst poisoning issues in fuel cell devices.

DNA strand displacement plays an important role in biological computations. The inherent advantages of parallelism, high storability, and cascading have resulted in increased functional circuit realization of DNA strand displacement on the nanoscale. Herein, we propose an analog computation with minus based on DNA strand displacement. The addition, subtraction, multiplication, and division gates as elementary gates could realize analog computation with minus. The advantages of this proposal are the analog computation with negative value and division computation. In this article, we provide the designs and principles of these elementary gates and demonstrate gate performance by simulation. Furthermore, to show the cascade property of gates, we computed a polynomial as an example by these gates.

Here, we report the synthesis and characterization of size-controllable and stimuli-responsive DNA nanohydrogels as effective targeted gene delivery vectors. DNA nanohydrogels were created through a self-assembly process using three kinds of building units, respectively termed Y-shaped monomer A with three sticky ends (YMA), Y-shaped monomer B with one sticky end (YMB), and DNA linker (LK) with two sticky ends. Hybridization at the sticky ends of monomers and LK leads to nanohydrogel formation. DNA nanohydrogels are size-controllable by varying the ratio of YMA to YMB. By incorporating different functional elements, such as aptamers, disulfide linkages, and therapeutic genes into different building units, the synthesized aptamer-based nanohydrogels (Y-gel-Apt) can be used for targeted and stimuli-responsive gene therapy. Y-gel-Apt strongly inhibited cell proliferation and migration in target A549 cells, but not in control cells. By taking advantage of facile modular design and assembly, efficient cellular uptake, and superior biocompatibility, this Y-gel-Apt holds great promise as a candidate for targeted gene or drug delivery and cancer therapy.

The first example of catalytic B–H activation of azaborines leading to a new family of stilbene derivatives through dehydrogenative borylation is reported. Ten 1,2-azaborine-based BN isosteres of stilbenes have been synthesized using this method, including a BN isostere of a biologically active stilbene. It is demonstrated that BN/CC isosterism in the context of stilbenes can lead to significant changes in the observed photophysical properties such as higher quantum yield and a larger Stokes shift. Direct comparative analysis of BN stilbene 3g and its carbonaceous counterpart 6g is consistent with a stronger charge-transfer character of the excited state exhibited by 3g in which the 1,2-azaborine heterocycle serves as a better electron donor than the corresponding arene.