Search

Our group pioneered the fabrication of stomatocyte-like colloidosomes (SCs) as motherships, on which different functional components could be conveniently loaded to construct versatile microrobots (SCbots) via one-step self-assembly. We report a flexible and universal route to create versatile SCbots with adjustable speeds and navigation capacities, which are in high demand for microrobots in various real applications. [Display omitted] • It's the first time for self-assembly of enzyme powered microrobots via colloidosomes. • Our versatile microrobots with enzyme activity retention above 91%. • This provides a new insight into the fabrication of asymmetrical microrobots. Building microrobots with asymmetric shapes is crucial to generate net driving forces, whereas often suffer from complex fabrication processes and limited availability of materials. Additionally, integrating diverse components into a single microscopic device for multifunctional microrobots is more challenging; however, if achieved, it offers promise for advanced microrobots with significantly expanded capabilities. Our group pioneered the fabrication of stomatocyte-like colloidosomes (SCs) as motherships, on which different functional components could be conveniently loaded to construct versatile microrobots (SCbots) via one-step self-assembly. It is the first time for self-assembly of enzyme powered microrobots via colloidosomes, the mechanism governing the formation of the target SCbots possessing asymmetrical narrow-opening stomatocyte shape is demonstrated. An additional benefit of SCbots is that their speed can be easily adjusted by changing the size of the shell-forming particles have been shown. As a proof of concept, like self-assembling macroscopic LEGO bricks, the proposed bottom-up strategy is used to access distinct versatile SCbots, including magnetically guided micro-carriers constructed from Fe 3 O 4 nanoparticles and a "chemistry-on-the-fly" platform for CO 2 sequestration constructed from carbonic anhydrase (CA). We report a flexible and universal route to create versatile SCbots with adjustable speeds and navigation capacities, which are in high demand for microrobots in various real applications. [ABSTRACT FROM AUTHOR]

• FL-MoS 2 -20 with V s gradient (16.3%) was prepared by a chemical etching strategy. • The high V s density can effectively boost N 2 adsorption and reduce E b for NRR. • The HER activity shows a "roller-coaster" type with the increased V s density. • Regulating the asynchronous evolution of NRR and HER results in a high selectivity. • FL-MoS 2 -20 rendered a high NH 3 yield rate (92.95 µg h −1 mg −1) and FE (20.80 %). The electrochemical N 2 reduction reaction (NRR) renders great potential for sustainable ammonia generation but still suffers from serious challenges, which limit the effective enhancement of catalytic performances. Herein, we skillfully utilize the asynchronous NRR and hydrogen evolution reaction (HER) activities as a function of S-vacancy (V s) concentrations to enhance the NRR activity but sacrifice the HER activity, thus achieving the tradeoff between activity and selectivity towards the NRR. Inspired by the theoretical guidance, the optimized catalyst (FL-MoS 2 -20) with a suitable V s concentration (16.30 %) renders a high NH 3 yield rate of 92.95 ± 2.10 µg h −1 mg −1 and a Faradic efficiency (FE) of 20.80 ± 0.18 %, exceeding virtually all previously published MoS 2 -based NRR catalysts and the overwhelming majority of state-of-the-art NRR catalysts. This work broadens the potential of vacancy engineering to manage the competitive reaction on a single active site and enlightens the catalyst design in the NRR field and beyond. [ABSTRACT FROM AUTHOR]

Although there are several reports showing the employment of aqueous two-phase systems (ATPS) for biotransformation in large-scale, the industrial application of ATPS is still hampered by their drawbacks such as slow diffusive mass transfer, long settling time for phase separation, and batch processes. Here, we propose for the first time a continuous-flow process based on a suitably designed ATPS parallel-laminar flow in a double Y-branched microfluidic device using for enzymatic catalysis. In a model urease reaction, polyethylene glycol (PEG) 8 kDa and dextran (Dex) 500 kDa are selected as polymer solutions, in which the enzymes settle mainly in the Dex phase while the products partition mainly to the PEG phase during short residence time. On account of rapid micro-transport, as well as integrate one single step of biocatalysis and separation process, obvious intensification of enzymatic catalysis in such ATPS microfluidic platform is demonstrated. Compared with the conventional ATPS in a beaker under gentle stirring, the enzymatic reaction rate in ATPS microfluidic is 500 times higher. Furthermore, the effects of flow rates, substrate concentration, residence time, and recycling number on the reaction rate and conversion rate are evaluated, respectively. Our study provides an all-aqueous, micro-scale and coupled reaction-separation platform for the process intensification of enzymatic catalysis, which has not only theoretical significance, but also practical value for biotransformation-based fields, such as biomedical, pharmaceuticals and food applications. [ABSTRACT FROM AUTHOR]

• Nanoscaled packing enzymes while preserving enzyme conformation is firstly reported. • This packing shortens intermediate transport distance and enhances cascade reaction. • The catalytic behavior of the packed enzymes is revealed. • Using the packed enzymes, glucose is detected with high sensitivity and selectivity. In nature, living cells form multienzyme complex by spatializing enzymes in confined compartments to enable cascade reactions. As these reactions are highly efficient and crucial to cellular metabolism, it is important to understand their catalytic behaviors. Herein, we report a living cell-inspired design of nanoscale multienzyme complex (nanocomplex), in which different enzymes are densely packed with intact conformations as the cellular multienzyme complex does, allowing sufficient transportation of intermedia and creating efficient cascade reactions. Benefit from the similarity between the proposed nanocomplex and cellular multienzyme complex, the systematic study of the effect of enzyme ratios and quantity to the nanocomplex reaction efficiency can inspire the investigation of the basic rules of cellular catalytic behaviors. In addition, the nanocomplex can also contribute to boosting the detection sensitivity of multienzyme-based biosensing due to its unsurpassed efficiency. Using the nanocomplex fabricated with methoxy polyethylene glycol (mPEG), glucose oxidase (GOx) and horseradish peroxidase (HRP), glucose in untreated urine, plasma and saliva samples can be detected with a remarkable detection limit of 1.6 µM and a detection time of just 30 s, surpass the current glucose detection approaches. Remarkably, the proposed sensor can also perform glucose detection with preserved cascade activity under high temperature, acid environment, or after long-time storage. Overall, this work can potentially provide a general understanding of multienzyme catalytic behaviors and a promising platform of ultrasensitive biosensing for disease diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Surface iodinated Bi 2 O 2 S were prepared as inspired [Bi 2 O 2 ]2+-containing materials. • Surface iodide ions facilitated the separation of photo-generated carriers in IBOS. • 2.0%IBOS exhibited superb abilities for the adsorption and activation toward CO 2. • The CH 4 yield of 80.03 μmol g−1 was achieved by visible light-driven CO 2 photoreduction. • The reaction mechanism was unveiled by experimental and theoretical analyses. Solar-energy-driven CO 2 conversion to green fuels has great potential to alleviate energy crises and environmental issues. However, the low separation efficiency of charge carriers and the weak adsorption ability towards CO 2 still hamper the efficiency of photocatalytic CO 2 reduction. Herein, surface iodinated Bi 2 O 2 S materials (IBOS) were demonstrated to be efficient [Bi 2 O 2 ]2+-containing photocatalysts, which could be prepared through facile hydrothermal process. The surface iodide ions are grafted onto the Bi atoms of Bi 2 O 2 S by replacing surface adsorbed OH, which slightly changes the electronic structure and then facilitates the separation of photo-generated electrons and holes in IBOS. Meanwhile, surface iodination also exhibits an enhanced adsorption and activation ability towards CO 2 , which contributes to photocatalytic CO 2 conversion to CH 4. The vital role of surface iodination was evidenced by the experimental analyses and theoretical calculations in detail. The optimized 2.0%IBOS shows marked photocatalytic CO 2 reduction performance with a CH 4 yield of 80.03 μmol g−1 under 90 min of visible light irradiation, which is ∼25-folds higher than pristine Bi 2 O 2 S. The mechanism of green transformation of CO 2 to CH 4 on 2.0%IBOS was finally proposed by the analyses of in situ FT-IR patterns. This work offers inspiration in designing and modifying [Bi 2 O 2 ]2+-containing photocatalysts for highly efficient photocatalytic CO 2 conversion. [ABSTRACT FROM AUTHOR]