Layered Black Phosphorus as a Selective Vapor Sensor Mayorga-Martinez, Carmen C.; Sofer, Zdeněk; Pumera, Martin
Angewandte Chemie (International ed.),
November 23, 2015, Letnik:
54, Številka:
48
Journal Article
Recenzirano
Odprti dostop
Black phosphorus is a layered material that is sensitive to the surrounding atmosphere. This is generally considered as a disadvantage, especially when compared to more stable layered compounds, such ...as graphite or MoS2. This sensitivity is now turned into an advantage. A vapor sensor that is based on layered black phosphorus and uses electrochemical impedance spectroscopy as the detection method is presented; the device selectively detects methanol vapor. The impedance phase measured at a constant frequency is used as a distinctive parameter for the selective quantification of methanol, and increases with the methanol concentration. The low detection limit of 28 ppm is well below the approved exposure limit of 200 ppm. The results are highly reproducible, and the vapor sensor is shown to be very selective in the presence of other vapors and to have long‐term stability.
Methanol detection: A vapor sensor that is based on layered black phosphorus and uses electrochemical impedance spectroscopy as the detection method selectively detects methanol. The impedance phase measured at a constant frequency is used as a distinctive parameter for the quantification of the methanol concentration with a low detection limit of 28 ppm.
Photocatalytic micromotors are light‐induced, chemically powered micromachines based on photocatalytic materials, activated by light illumination, and have redox reactions with environmental ...solutions to produce chemical gradients and bubbles that propel the micromachines through self‐diffusiophoresis, self‐electrophoresis, and bubble recoil. Due to the fact that excitation light relates largely to the bandgaps of selected materials, the development of photocatalytic micromotors has experienced an evolution from ultraviolet‐light‐activated to visible‐light‐activated and potentially biocompatible systems. Furthermore, due to the strong redox capacity and physical effects caused by the products or product gradients, photocatalytic micromotors have applications in environmental remediation, micropumps, reversible assembly, transportation, and biomimicry.
Photocatalytic micro/nanomotors (MNMs) are ultraviolet‐ or visible‐light‐induced, chemically powered MNMs based on photocatalytic materials and demonstrate potential applications in environmental remediation, micropumps, reversible assembly, transportation, and biomimicry (phototaxis).
Two‐dimensional materials have allowed for great advances in the biosensors field and to obtain sophisticated, smart, and miniaturized devices. In this work, we optimized a highly sensitive and ...selective phenol biosensor using 2D pnictogens (phosphorene, arsenene, antimonene, and bismuthene) as sensing platforms. Exfoliated pnictogen were obtained by the shear‐force method, undergoing delamination and downsizing to thin nanosheets. Interestingly, compared with the other tested elements, antimonene exhibited the highest degree of exfoliation and the lowest oxidation‐to‐bulk ratio, to which we attribute its enhanced performance in the phenol biosensor system reported here. The proposed design represents the first biosensor approach developed using exfoliated pnictogens beyond phosphorene.
Biosensors based on thin nanosheets of 2D antimonene were used for phenol detection. This phenol biosensor shows enhanced analytical performance when compared to the other pnictogens in terms of linearity, sensitivity, selectivity, and reproducibility.
mTORC2 phosphorylates AKT in a hydrophobic motif site that is a biomarker of insulin sensitivity. In brown adipocytes, mTORC2 regulates glucose and lipid metabolism, however the mechanism has been ...unclear because downstream AKT signaling appears unaffected by mTORC2 loss. Here, by applying immunoblotting, targeted phosphoproteomics and metabolite profiling, we identify ATP-citrate lyase (ACLY) as a distinctly mTORC2-sensitive AKT substrate in brown preadipocytes. mTORC2 appears dispensable for most other AKT actions examined, indicating a previously unappreciated selectivity in mTORC2-AKT signaling. Rescue experiments suggest brown preadipocytes require the mTORC2/AKT/ACLY pathway to induce PPAR-gamma and establish the epigenetic landscape during differentiation. Evidence in mature brown adipocytes also suggests mTORC2 acts through ACLY to increase carbohydrate response element binding protein (ChREBP) activity, histone acetylation, and gluco-lipogenic gene expression. Substrate utilization studies additionally implicate mTORC2 in promoting acetyl-CoA synthesis from acetate through acetyl-CoA synthetase 2 (ACSS2). These data suggest that a principal mTORC2 action is controlling nuclear-cytoplasmic acetyl-CoA synthesis.
Self‐Propelled Tags for Protein Detection Mayorga‐Martinez, Carmen C.; Pumera, Martin
Advanced functional materials,
02/2020, Letnik:
30, Številka:
6
Journal Article
Recenzirano
Protein detection is of tremendous significance for biological and biomedical sciences. Because there is no equivalent of polymerase chain reaction available as a tool for protein detection, ...researchers must rely on tags to enhance the limits of detection. One of the crucial steps is the actual labeling of proteins, which relies on diffusion of the label, which is very slow, or external mixing of the label and protein is needed. Here, a conceptually new approach is demonstrated: self‐propelled tags that autonomously move in the solution and enhance protein detection. The tags used here are based on IrO2/Pt bilayer microtubules, which can self‐propel and act as moving tags for enhanced protein electrochemical detection. This completely new label‐based protein detection concept using self‐propelled tag will find a wide spectrum of applications.
Self‐propelled tags based on IrO2/Pt bilayer microtubules autonomously move and act as moving tags for enhanced protein electrochemical detection. This new label‐based protein detection concept using self‐propelled tags will find a wide spectrum of applications.
Ultrasound at sufficiently low amplitudes, specifically in the MHz frequency range, does little harm to the biological samples (such as cells and tissues) and provides an advantageous and ...well‐controlled means to efficiently power microswimmers. In this review, a state‐of‐the‐art overview of ultrasonically propelled micro‐ and nanorobots from the perspective of chemistry, physics, and materials science is given. First, the well‐established theory of ultrasound propulsion for micro/nanorobots is introduced. Second, the setup designs for ultrasound propulsion of micro/nanorobots are classified. Following this, the presentative fabrication methods of ultrasonic micro/nanorobots are summarized in detail. After this, the mechanisms of ultrasound propulsion for micro/nanorobots are explored and discussed. The hybrid motion of magnetic‐, light‐, and catalytic‐driven micro/nanorobots with ultrasonic actuation is then summarized and discussed. Subsequently, this review highlights and discusses representative potential applications of ultrasound‐powered functional micro/nanorobots in biomedical, environmental, and other relevant fields. Lastly, this review presents a future outlook on the ultrasound‐driven micro/nanorobots.
Ultrasonically propelled micro/nanorobots provide numerous advantageous. Here, the current progress of ultrasonically propelled micro/nanorobots upon their propulsion mechanism, detailed description of their fabrication methods, hybrid motion in combination with another propulsion mechanism as well as their potential application in biomedical, environmental, and other fields is discussed.
Prostate cancer is the most commonly diagnosed tumor disease in men, and its treatment is still a big challenge in standard oncology therapy. Magnetically actuated microrobots represent the most ...promising technology in modern nanomedicine, offering the advantage of wireless guidance, effective cell penetration, and non‐invasive actuation. Here, new biodegradable magnetically actuated zinc/cystine‐based microrobots for in situ treatment of prostate cancer cells are reported. The microrobots are fabricated via metal‐ion‐mediated self‐assembly of the amino acid cystine encapsulating superparamagnetic Fe3O4 nanoparticles (NPs) during the synthesis, which allows their precise manipulation by a rotating magnetic field. Inside the cells, the typical enzymatic reducing environment favors the disassembly of the aminoacidic chemical structure due to the cleavage of cystine disulfide bonds and disruption of non‐covalent interactions with the metal ions, as demonstrated by in vitro experiments with reduced nicotinamide adenine dinucleotide (NADH). In this way, the cystine microrobots served for site‐specific delivery of Zn2+ ions responsible for tumor cell killing via a “Trojan horse effect”. This work presents a new concept of cell internalization exploiting robotic systems’ self‐degradation, proposing a step forward in non‐invasive cancer therapy.
A metal‐ion‐mediated self‐assembly approach is used to synthesize magnetically driven cystine microrobots, whose motion can be precisely manipulated by a transversal rotating magnetic field. After their internalization in prostate cancer cells, the typical enzymatic reducing environment favors the microrobots disassembly for site‐specific delivery of Zn2+ ions responsible for tumor cell killing via a “Trojan horse” effect.
Research on wearable sensing technologies has been gaining considerable attention in the development of portable bio‐monitoring devices for personal health. However, traditional energy storage ...systems with defined size and shape have inherent limitations in satisfying the performance requirements for flexible electronics. To overcome this constraint, three different configurations of flexible asymmetric supercapacitor (FASC) are fabricated on polyester/cellulose blend (PCB) cloth substrate using Ti3C2 nanosheet (NS) and 1T WS2 NS as electrodes, and aqueous pluronic gel as an electrolyte. Benefiting from the 2D material electrodes, the interdigitated FASC configuration exhibits excellent performance, flexibility, cyclic stability, wearability and can be configured into multiple units and shapes, which far exceed that exhibited by the textile‐based FASC. Furthermore, the arbitrary (“AFN”) and sandwich (“FLOWER”) configurations Ti3C2 NS/1T WS2 NS FASC can be assembled directly on a PCB cloth substrate, thereby offering good structural integrity coupled with ease of assembly into integrated circuits of different shapes. More specifically, a lightweight, flexible, and wearable bio‐monitoring system is developed by integrating force sensing device with interdigitated FASC, which can be used to monitor the physical status of human body during various activities. A potential application of this system in healthcare is successfully demonstrated and discussed.
An integrated bio‐monitoring system with a Ti3C2 NS/1T WS2 NS based flexible supercapacitor and force sensor device is developed. The proof of concept for practical application of this system is demonstrated by monitoring live artery pulse and feet alignment analysis on a human subject.
•A 7-degree-of-freedom model of hybrid electric vehicle with regenerative braking system is built.•A modified nonlinear model predictive control strategy is developed.•The particle swarm optimization ...algorithm is employed to solve the optimization problem.•The proposed control strategy is verified by simulation and hardware-in-loop tests.•Test results verify the effectiveness of the proposed control strategy.
As one of the main working modes, the energy recovered with regenerative braking system provides an effective approach so as to greatly improve fuel economy of hybrid electric bus. However, it is still a challenging issue to ensure braking stability while maximizing braking energy recovery. To solve this problem, an efficient energy recovery control strategy is proposed based on the modified nonlinear model predictive control method. Firstly, combined with the characteristics of the compound braking process of single-shaft parallel hybrid electric bus, a 7 degrees of freedom model of the vehicle longitudinal dynamics is built. Secondly, considering nonlinear characteristic of the vehicle model and the efficiency of regenerative braking system, the particle swarm optimization algorithm within the modified nonlinear model predictive control is adopted to optimize the torque distribution between regenerative braking system and pneumatic braking system at the wheels. So as to reduce the computational time of modified nonlinear model predictive control, a nearest point method is employed during the braking process. Finally, the simulation and hardware-in-loop test are carried out on road conditions with different tire–road adhesion coefficients, and the proposed control strategy is verified by comparing it with the conventional control method employed in the baseline vehicle controller. The simulation and hardware-in-loop test results show that the proposed strategy can ensure vehicle safety during emergency braking situation and improve the recovery energy almost 17% compared with the conventional rule-based strategy in the general braking situation. Therefore, the proposed control strategy might offer a theoretical reference for the design of the actual braking controller in engineering practice.
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