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.
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.
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.
Nowadays, microrobots are considered appealing mobile carriers for clinical therapies. In this sense, high expectations against unmet medical challenges have been created around microswimmers that ...combine autonomous navigation with enhanced abilities to perform specific tasks. Neurodegenerative disorders are incurable diseases that have a huge impact on the quality of life for millions of people. To date, protein disaggregation (i.e., dissociation of mature protein fibrils on the origin of the given illness) has been discussed as targeted therapy by means of nonautonomous nanoparticles. Here, self‐propelled light‐driven single‐component micromotors based on concave BiVO4 microspheres are used to disaggregate protein fibrils. Efficient disaggregation is proved to be promoted by the micromotors’ intrinsic on‐the‐fly generation of reactive oxygen species (ROS). Moreover, the helical trajectories observed for these single‐component micromotors are thought to be probably behind the uniform distribution of ROS, leading to enhanced protein dissociation. This conceptually promising application of light‐driven micromotors with efficient photocatalytic ROS production and distribution can be extended to alternative ROS‐based photodynamic therapies against lung or skin cancer, among others.
Self‐propelled light‐driven single‐component micromotors are used to disaggregate protein fibrils. In particular, concave BiVO4 microspheres promote the efficient protein dissociation of the proteins thanks to the on‐the‐fly generation and uniform distribution of reactive oxygen species. With this conceptually innovative application of light‐driven micromotors, new efficient medical treatments can be devised for the battle against those currently incurable neurodegenerative diseases.
Two-dimensional (2D) materials are at the forefront of materials research. Here we overview their applications beyond graphene, such as transition metal dichalcogenides, monoelemental Xenes ...(including phosphorene and bismuthene), carbon nitrides, boron nitrides along with transition metal carbides and nitrides (MXenes). We discuss their usage in various biomedical and environmental monitoring applications, from biosensors to therapeutic treatment agents, their toxicity and their utility in chemical sensing. We highlight how a specific chemical, physical and optical property of 2D materials can influence the performance of bio/sensing, improve drug delivery and photo/thermal therapy as well as affect their toxicity. Such properties are determined by crystal phases electrical conductivity, degree of exfoliation, surface functionalization, strong photoluminescence, strong optical absorption in the near-infrared range and high photothermal conversion efficiency. This review conveys the great future of all the families of 2D materials, especially with the expanding 2D materials' landscape as new materials emerge such as germanene and silicene.
The growing consumption of drugs of abuse together with the inefficiency of the current wastewater treatment plants toward their presence has resulted in an emergent class of pollutants. Thus, the ...development of alternative approaches to remediate this environmental threat is urgently needed. Microrobots, combining autonomous motion with great tunability for the development of specific tasks, have turned into promising candidates to take on the challenge. Here, hybrid urchin‐like hematite (α‐Fe2O3) microparticles carrying magnetite (Fe3O4) nanoparticles and surface functionalization with organic β‐cyclodextrin (CD) molecules are prepared with the aim of on‐the‐fly encapsulation of illicit drugs into the linked CD cavities of moving microrobots. The resulting mag‐CD microrobots are tested against methamphetamine (MA), proving their ability for the removal of this psychoactive substance. A dramatically enhanced capture of MA from water with active magnetically powered microrobots when compared with static passive CD‐modified particles is demonstrated. This work shows the advantages of enhanced mass transfer provided by the externally controlled magnetic navigation in microrobots that together with the versatility of their design is an efficient strategy to clean polluted waters.
The study explores the use of magnetic cyclodextrin (CD) functionalized microrobots for cleaning water contaminated with drug residues, specifically methamphetamine. These microrobots, with a hematite/magnetite core and CD surface, enhance pollutant removal due to their combined magnetic movement and hydrophobic cavities of CDs on microrobot surfaces. The design emphasizes autonomous movement, improved mass transfer, and targeted functionalization for effective remediation.
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.
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