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Heng Ye, Guofeng Ma, Jian Kang, Hongqi Sun, Shaobin Wang
Herein, we demonstrate that iron oxide modified MnO2 (FeOx-MnO2) catalyzed micromotors can be fabricated via electrochemical co-reduction and exhibit exceptional high performance at an extremely low hydrogen peroxide (H2O2) fuel concentration. We observed that graphene/FeOx-MnO2 microtubes could show motion behaviors at fuel concentration as low as 0.03% H2O2, which is nearly one order of magnitude lower than Pt-based micromotors (normally at above 0.2% H2O2). Moreover, the micromotors exhibit higher speeds than any other reported catalytic micro/nanomotors (MNMs) at low peroxide levels...
April 6, 2018: Chemical Communications: Chem Comm
Mahmoud Amouzadeh Tabrizi, Mojtaba Shamsipur, Reza Saber, Saeed Sarkar
Herein, aptamer-modified self-propelled nanomotors were used for transportation of human promyelocytic leukemia cells (HL-60) from a human serum sample. For this purpose, the fabricated manganese oxide nanosheets-polyethyleneimine decorated with nickel/gold nanoparticles (MnO2 -PEI/Ni/Au) as nanomotors were added to a vial containing thiolated aptamer KH1C12 solution as a capture aptamer to attach to the gold nanoparticles on the surface of nanomotors covalently. The aptamer-modified self-propelled nanomotors (aptamerKH1C12 /nanomotors) were then separated by placing the vial in a magnetic stand...
March 17, 2018: Biosensors & Bioelectronics
Chuanrui Chen, Emil Karshalev, Jianguo Guan, Joseph Wang
The new capabilities and functionalities of synthetic micro/nanomotors open up considerable opportunities for diverse environmental and biomedical applications. Water-powered micromachines are particularly attractive for realizing many of these applications. Magnesium-based motors directly use water as fuel to generate hydrogen bubbles for their propulsion, eliminating the requirement of common toxic fuels. This Review highlights the development of new Mg-based micromotors and discusses the chemistry that makes it extremely attractive for micromotor applications...
March 9, 2018: Small
Kun Cai, Jiao Shi, Jingzhou Yu, Qing H Qin
When argon is used as a protecting gas in the fabrication or working environment of a nanodevice, absorption of some argon atoms onto the surface of the device lead to different responses. In this work, the rotation of the rotor in a carbon nanotube (CNT)-based rotary nanomotor in argon environment is investigated. In the rotary nanomotor, two outer CNTs act as the stator and are used to constrain the inner CNT (i.e., the rotor). The rotor is driven to rotate by the stator due to their collision during thermal vibration of their atoms...
February 22, 2018: Scientific Reports
Emil Karshalev, Berta Esteban-Fernández de Ávila, Joseph Wang
This perspective reviews mobile micro/nanomotor scaffolds for performing "chemistry-on-the-fly". Synthetic nano/micromotors offer great versatility and distinct advantages in diverse chemical applications owing to their efficient propulsion and facile surface functionalization that allow these mobile platforms to move and disperse reactive materials across the solution. Such dynamic microreactors have led to accelerated chemical processes, including organic pollutant degradation, metal chelation, biorecognition, redox chemistry, chemical 'writing' and a variety of other chemical transformations...
February 22, 2018: Journal of the American Chemical Society
Tetiana Orlova, Federico Lancia, Charles Loussert, Supitchaya Iamsaard, Nathalie Katsonis, Etienne Brasselet
Molecular machines operated by light have been recently shown to be able to produce oriented motion at the molecular scale1,2 as well as do macroscopic work when embedded in supramolecular structures3-5. However, any supramolecular movement irremediably ceases as soon as the concentration of the interconverting molecular motors or switches reaches a photo-stationary state6,7. To circumvent this limitation, researchers have typically relied on establishing oscillating illumination conditions-either by modulating the source intensity8,9 or by using bespoke illumination arrangements10-13...
February 12, 2018: Nature Nanotechnology
Muhammad Safdar, Shahid Ullah Khan, Janne Jänis
Synthetic micro- and nanomotors (MNMs) are tiny objects that can autonomously move under the influence of an appropriate source of energy, such as a chemical fuel, magnetic field, ultrasound, or light. Chemically driven MNMs are composed of or contain certain reactive material(s) that convert chemical energy of a fuel into kinetic energy (motion) of the particles. Several different materials have been explored over the last decade for the preparation of a wide variety of MNMs. Here, the discovery of materials and approaches to enhance the efficiency of chemically driven MNMs are reviewed...
February 7, 2018: Advanced Materials
Ibon Santiago, Luyun Jiang, John Foord, Andrew J Turberfield
Asymmetric bimetallic nanomotors are synthesised by seeded growth in solution, providing a convenient and high-throughput alternative to the usual top-down lithographic fabrication of self-propelled catalytic nanoparticles. These synthetic nanomotors catalyse H2O2 decomposition and exhibit enhanced diffusion that depends on fuel concentration, consistent with their chemical propulsion.
February 2, 2018: Chemical Communications: Chem Comm
Francisco Mendoza-Hoffmann, Ángeles Pérez-Oseguera, Miguel Ángel Cevallos, Mariel Zarco-Zavala, Raquel Ortega, Claudia Peña-Segura, Emilio Espinoza-Simón, Salvador Uribe-Carvajal, José J García-Trejo
The biological roles of the three natural F1FO-ATPase inhibitors, ε, ζ, and IF1, on cell physiology remain controversial. The ζ subunit is a useful model for deletion studies since it mimics mitochondrial IF1, but in the F1FO-ATPase of Paracoccus denitrificans (PdF1FO), it is a monogenic and supernumerary subunit. Here, we constructed a P. denitrificans 1222 derivative (PdΔζ) with a deleted ζ gene to determine its role in cell growth and bioenergetics. The results show that the lack of ζ in vivo strongly restricts respiratory P...
January 23, 2018: Cell Reports
Diana Vilela, Unai Cossío, Jemish Parmar, Angel M Martínez-Villacorta, Vanessa Gómez-Vallejo, Jordi Llop, Samuel Sánchez
Micro/nanomotors are useful tools for several biomedical applications, including targeted drug delivery and minimally invasive microsurgeries. However, major challenges such as in vivo imaging need to be addressed before they can be safely applied on a living body. Here, we show that positron emission tomography (PET), a molecular imaging technique widely used in medical imaging, can also be used to track a large population of tubular Au/PEDOT/Pt micromotors. Chemisorption of an iodine isotope onto the micromotor's Au surface rendered them detectable by PET, and we could track their movements in a tubular phantom over time frames of up to 15 min...
February 27, 2018: ACS Nano
Pooyath Lekshmy Venugopalan, Shilpee Jain, Srinivasrao Shivashankar, Ambarish Ghosh
Magnetic nanomotors with integrated theranostic capabilities can revolutionize biomedicine of the future. Typically, these nanomotors contain ferromagnetic materials, such that small magnetic fields can be used to maneuver and localize them in fluidic or gel-like environments. Motors with large permanent magnetic moments tend to agglomerate, which limits the scalability of this otherwise promising technology. Here, we demonstrate the application of a microwave-synthesized ferrite layer to reduce the agglomeration of helical ferromagnetic nanomotors by an order of magnitude, which allows them to be stored in a colloidal suspension for longer than six months and subsequently be manoeuvred with undiminished performance...
February 1, 2018: Nanoscale
Malthe Hansen-Bruhn, Berta Esteban-Fernández de Ávila, Mara Beltrán-Gastélum, Jing Zhao, Doris E Ramírez-Herrera, Pavimol Angsantikul, Kurt Vesterager Gothelf, Liangfang Zhang, Joseph Wang
Direct and rapid intracellular delivery of a functional Cas9/sgRNA complex using ultrasound-powered nanomotors is reported. The Cas9/sgRNA complex is loaded onto the nanomotor surface through a reversible disulfide linkage. A 5 min ultrasound treatment enables the Cas9/sgRNA-loaded nanomotors to directly penetrate through the plasma membrane of GFP-expressing B16F10 cells. The Cas9/sgRNA is released inside the cells to achieve highly effective GFP gene knockout. The acoustic Cas9/sgRNA-loaded nanomotors display more than 80 % GFP knockout within 2 h of cell incubation compared to 30 % knockout using static nanowires...
March 1, 2018: Angewandte Chemie
Jianhe Guo, Jeremie June Gallegos, Ashley Robyn Tom, Donglei Fan
We report a controllable and precision approach in manipulating catalytic nanomotors by strategically applied electric (E-) fields in three dimensions (3-D). With the high controllability, the catalytic nanomotors have demonstrated versatility in capturing, delivering, and releasing of cargos to designated locations as well as in situ integration with nanomechanical devices (NEMS) to chemically power the actuation. With combined AC and DC E-fields, catalytic nanomotors can be accurately aligned by the AC E-fields and effectively change their speeds instantly by the DC E-fields...
February 27, 2018: ACS Nano
Hyunsik Choi, Geon-Hui Lee, Ki Su Kim, Sei Kwang Hahn
Machines have greatly contributed to the human civilization, enabling tasks beyond our capacities for improved quality of life. Recently, the progress in nanotechnology has triggered to build a miniaturized machine of nanoscale. In this context, synthetic nanomotors have gained considerable interest because of their great promise for diverse applications. Currently, the movement control of these nanomotors has been widely investigated using various stimuli. Here, we demonstrate near-infrared (NIR) light controlled on/off motion of stomatocyte nanomotors powered by the conversion of hydrogen peroxide...
January 24, 2018: ACS Applied Materials & Interfaces
Pierre Gaspard, Raymond Kapral
Microscopic dynamical aspects of the propulsion of nanomotors by self-phoretic mechanisms are considered. Propulsion by self-diffusiophoresis relies on the mechanochemical coupling between the fluid velocity field and the concentration fields induced by asymmetric catalytic reactions on the motor surface. The consistency between the thermodynamics of this coupling and the microscopic reversibility of the underlying molecular dynamics is investigated. For this purpose, a mechanochemical fluctuation theorem for the joint probability to find the motor at position r after n reactive events have occurred during the time interval t is derived, starting from coupled Langevin equations for the translational, rotational, and chemical fluctuations of self-phoretic motors...
December 7, 2017: Journal of Chemical Physics
Jinxing Li, Pavimol Angsantikul, Wenjuan Liu, Berta Esteban-Fernández de Ávila, Xiaocong Chang, Elodie Sandraz, Yuyan Liang, Siyu Zhu, Yue Zhang, Chuanrui Chen, Weiwei Gao, Liangfang Zhang, Joseph Wang
One emerging and exciting topic in robotics research is the design of micro-/nanoscale robots for biomedical operations. Unlike industrial robots that are developed primarily to automate routine and dangerous tasks, biomedical nanorobots are designed for complex, physiologically relevant environments, and tasks that involve unanticipated biological events. Here, a biologically interfaced nanorobot is reported, made of magnetic helical nanomotors cloaked with the plasma membrane of human platelets. The resulting biomimetic nanorobots possess a biological membrane coating consisting of diverse functional proteins associated with human platelets...
January 2018: Advanced Materials
Chuanrui Chen, Xiaocong Chang, Hazhir Teymourian, Doris E Ramírez-Herrera, Berta Esteban-Fernández de Ávila, Xiaolong Lu, Jinxing Li, Sha He, Chengcheng Fang, Yuyan Liang, Fangzhi Mou, Jianguo Guan, Joseph Wang
While chemical communication plays a key role in diverse natural processes, the intelligent chemical communication between synthetic nanomotors remains unexplored. The design and operation of bioinspired synthetic nanomotors is presented. Chemical communication between nanomotors is possible and has an influence on propulsion behavior. A chemical "message" is sent from a moving activator motor to a nearby activated (receiver) motor by release of Ag+ ions from a Janus polystyrene/Ni/Au/Ag activator motor to the activated Janus SiO2 /Pt nanomotor...
January 2, 2018: Angewandte Chemie
Sebastian Gliga, Gino Hrkac, Claire Donnelly, Jonathan Büchi, Armin Kleibert, Jizhai Cui, Alan Farhan, Eugenie Kirk, Rajesh V Chopdekar, Yusuke Masaki, Nicholas S Bingham, Andreas Scholl, Robert L Stamps, Laura J Heyderman
Modern nanofabrication techniques have opened the possibility to create novel functional materials, whose properties transcend those of their constituent elements. In particular, tuning the magnetostatic interactions in geometrically frustrated arrangements of nanoelements called artificial spin ice can lead to specific collective behaviour, including emergent magnetic monopoles, charge screening and transport, as well as magnonic response. Here, we demonstrate a spin-ice-based active material in which energy is converted into unidirectional dynamics...
October 23, 2017: Nature Materials
Xiao-Ni Zhang, Kun Cai, Jiao Shi, Qing-Hua Qin
The rotation transmission system (RTS) made from co-axial multi-walled nanotubes (MWNTs) has the function of regulating the input rotation from a nanomotor. The mechanism for the regulation is that the friction among the tubes during rotation governs the rotation of the rotors in the nanosystem. By integrating a rotary nanomotor and a nanobearing into an MWNT-based RTS, it is discovered that the stator (outer tube) provides relatively greater friction on the rotors by penetrating the motor tube, which has a higher stable rotational frequency...
January 26, 2018: Nanotechnology
Dekai Zhou, Liqiang Ren, Yuguang C Li, Pengtao Xu, Yuan Gao, Guangyu Zhang, Wei Wang, Thomas E Mallouk, Longqiu Li
We report the synthesis and properties of rod-shaped gold/iron oxide nanomotors that are powered by visible light in dilute hydrogen peroxide solutions. Electrochemical measurements confirmed that the light-driven nanomotors operate by a self-electrophoretic mechanism, modulated by the photovoltage and the photoconductivity of gold/iron oxide. Due to the magnetism of iron oxide, the nanomotors can be steered by an external magnetic field without incorporating additional magnetic materials into the nanomotors...
October 17, 2017: Chemical Communications: Chem Comm
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