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Converting carbon dioxide into formic acid with formate dehydrogenase (FDH) as a catalyst is a gentle and eco‐friendly process that not only conserves energy and reduces emissions but transforms waste into valuable resource. Enzyme immobilization is a common strategy for improving the stability and recyclability of enzyme, however, the procedures are usually complicated that include surface modification and binding reactions in order to form reliable linkages. Co‐deposition of polydopamine (PDA) with polyethyleneimine (PEI) is a popular surface modification approach in versatile fields, but their co‐deposition with enzymes is rarely reported. Herein, one‐pot immobilization of FDH on SiO2 nanoparticles based on catechol chemistry was attempted for the first time with or without PEI, and the resultant immobilized enzymes, FDH/PDA/PEI‐SiO2 and FDH/PDA‐SiO2, were characterized, and the effects of the composition and deposition conditions on the catalytic performance were investigated. FDH/PDA‐SiO2 exhibited a higher apparent specific activity than FDH/PDA/PEI‐SiO2, which was separately 0.167 and 0.136 mM/h/mg. The activity recovery rate was 464% and 378% of that of free enzyme. After 5 cycles, their relative activity was 82.3% and 87.4%. This research is significant in presenting a simple and high‐efficient one‐pot immobilization method that can be extended to other kinds of enzymes. [ABSTRACT FROM AUTHOR]

Baloxavir marboxil is a novel anti-influenza drug with a unique mechanism of action that can effectively treat both type A and type B influenza. Key intermediate compound 7,8-difluoro-6,11-dihydrodibenz[b,e]thiophene-11-one is not only an important component of the chemical structure of baloxavir marboxil but also an essential intermediate in the synthetic route of the drug. However, conventional synthesis methods for key intermediate 7,8-difluoro-6,11-dihydrodibenz[b,e]thiophene-11-one usually utilize dangerous and harmful chemicals that can cause significant environmental pollution during large-scale production. This article proposes a new synthesis route for 7,8-difluoro-6,11-dihydrodibenz[b,e]thiophene-11-one to facilitate large-scale production while integrating the principles of green chemistry. This new route feature mild reaction conditions and simpler steps that result in an overall yield increase to 64.9%. More significantly, the new synthesis route reduces the use of hazardous chemicals, thus limiting the generation of hazardous waste during industrial production. This research offers significant potential for environmental pollution control.

Trimerizing furoxans are ideal molecular skeletons for the construction of high energetic substances due to their compact structures and high enthalpy of formations. To explore and compare the thermal behaviors of energetic materials with tandem trimerizing furoxan molecular skeleton, we reported the first systematic research on the thermochemical behaviors and decomposition mechanism of 3,4‐bis(3‐fluorodinitromethylfuroxan‐4‐yl)furoxan (BFTF), 3,4‐bis(3‐cyanofurazan)furazan oxide (BCTFO) and benzotrifuroxan (BTF). According to the research results of the DSC‐TG experiments, both the substituted furoxan based energetic compounds (BCTFO and BFTF) exhibited low melting points and complicated thermal decomposition behaviors around 240 °C, while the melting point of unsubstituted furoxan (BTF) was much higher. Their detailed decomposition mechanisms were proposed based on the experimental results through tandem techniques including in‐situ FTIR spectroscopy method and DSC‐TG‐FTIR‐MS quadruple technology, which indicated that the cleavage of substituent would trigger the decompositions of BFTF and the decomposition of trimerizing furoxan skeletons almost synchronous occurrence with substituents in BCTFO. The self‐oxidation‐reduction of the linear and annular trimerizing furoxans lead to similar decomposition fragmented small molecule products. [ABSTRACT FROM AUTHOR]

Portable sensors with high selectivity and sensitivity are essential for ammonia detection. In this work, a colorimetric sensor based on non-close-packed photonic crystals (NPCs) was developed for visual monitoring of ammonia, which had great selectivity, stability, and durability. The initial structural color of the NPCs was customized in the entire color range by tuning the PMMA concentration and acrylamide (AM) content. Ethylene glycol-NPCs (EG-NPCs) with a softer texture were obtained by swelling of the NPCs in 5% glycerol & 30% ethylene glycol solution, and the reflective peak of the EG-NPCs with 50 mg mL−1 AM shifted from 459 nm to 626 nm. Besides, the abundant hydroxyl groups in the EG-NPCs can form hydrogen bonds with ammonia, resulting in a greater decrease in the lattice distance. The reflective peak of the EG-NPCs blue shifted from 626 nm to 482 nm when the ammonia concentration increased from 0 μL cm−3 to 0.12 μL cm−3, and the δλ = 144 nm, which realized colorimetric sensing in the entire visible color range. The excellent selectivity, stability, and durability of the colorimetric sensors make it possible to sense ammonia in the air, which is critical for the safe production of chemical plants, farms, and other key sites. [ABSTRACT FROM AUTHOR]

Theoretical calculations and numerical simulations play a crucial role in analyzing material properties and devising effective research strategies. In this study, the photonic band gap (PBG) of polymethyl methacrylate (PMMA) and polystyrene (PS) photonic crystals was successfully predicted using theoretical calculations and numerical simulations. The agreement between the predicted results and the actual reflection peaks reached an impressive level of 99%. Utilizing SEM images, the prediction of reflection peaks in acrylamide (AM)—based photonic hydrogels was conducted using theoretical formulas and Rsoft 2019–Bandsolve software v2019.09. The relationship between the actual reflection peaks and compressive strains in AM-based photonic hydrogels featuring 251 nm PMMA PCs exhibited a remarkable similarity of over 96% with the theoretical and simulated results. In conclusion, an exploration was conducted into the relationship between reflection peaks and compressive strains for AM-based 270 nm PMMA photonic hydrogels, allowing the prediction of the actual reflection peaks under compression. The consistency observed between theoretical/simulated reflection peaks and actual reflection peaks validates the efficacy of this approach in evaluating the optical properties of photonic materials and predicting their responsive effects. This method offers a straightforward and expeditious solution for the design and fabrication of photonic materials. [ABSTRACT FROM AUTHOR]

In recent years, mechano-actuated sensors have received extensive attention due to their excellent sensitivity in the dynamic pressure and flow field. In this study, a mechanochromic optical sensor based on Bragg reflection was fabricated, which can realize ultra-fast real-time monitoring of large-range sharp pressure fluctuations. To enhance environmental adaptability, the effects of concentration and zeta potential on the optical properties of a NPC hydrogel were discussed, and the hydrogel was integrated with polydimethylsiloxane and graphene oxide as sensors. The reflection peak of the NPC hydrogel shifted from 633 nm to 397 nm and the structural color changed from red to blue at 173 kPa. The optical sensor was designed with maximum measuring ranges of 407.1 kPa, 1.59 MPa, 4.15 MPa, 9.52 MPa and 15.50 MPa and their feasibility was verified by cavitation. Simulation and actual monitoring results showed that the sensors can realize the real-time monitoring of large-range sharp pressure fluctuations in aqueous fluids, their structural color can be changed in ultrafast conversion and recovery within 0.0001 s, and the spatial resolution was 0.21 mm. This work provides a novel strategy for real-time monitoring of large-range sharp pressure fluctuations in aqueous fluids, which created a precedent for ultra-fast visual monitoring of large-scale and dramatic pressure fluctuations. [ABSTRACT FROM AUTHOR]

Plasmonic nanostructures have attracted extensive attention for killing cancer cells in photothermal therapy due to their significant absorption activities and photothermal conversion capabilities. However, the development of anisotropic plasmonic nanostructures with tunable near-infrared (NIR) absorptions remains a great challenge. In this study, Fe2O3@Au hexagonal nanodisks (NDs) are prepared by a space-confined growth approach. By choosing uniform and size-tunable Fe2O3 nanodisks as the initial templates, the localized surface plasmon resonance (LSPR) peaks of Au NDs are accurately tuned in the NIR therapeutic window. In addition, by improving the effective photothermal absorption, a high photothermal conversion effect that can exceed 70 °C with 808 nm laser irradiation (2 W cm−2) for 7 min is achieved by 120 nm Fe2O3@Au NDs. We further demonstrate that these Fe2O3@Au NDs simultaneously have both low cytotoxicity and high photothermal therapy (PTT) performance of 89% cancer cell inactivation rate, and can be employed as photothermal therapeutic agents for effective photothermal therapy for cancer cells. This study will provide new insights into a wide range of applications for designing anisotropic plasmonic structures with LSPR enhancement activities. [ABSTRACT FROM AUTHOR]