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Martin Pumera
Self-propelled micro/nanomotors are synthetic machines that can convert different sources of energy into motion; at the same time, they are able to serve innovative environmental applications, e.g., water purification. The self-propelled autonomous micro and nanomachines can rapidly zoom through the solution, carrying catalytic surface or chemical to remove or degrade pollutants in much faster fashion than static systems which depend on diffusion and fluxes. This review highlights the recent progress of MNMs in water pollutant detection and removal applications...
October 11, 2018: Chemistry: a European Journal
Francisco Mendoza-Hoffmann, Mariel Zarco-Zavala, Raquel Ortega, José J García-Trejo
The ATP synthase is a ubiquitous nanomotor that fuels life by the synthesis of the chemical energy of ATP. In order to synthesize ATP, this enzyme is capable of rotating its central rotor in a reversible manner. In the clockwise (CW) direction, it functions as ATP synthase, while in counter clockwise (CCW) sense it functions as an proton pumping ATPase. In bacteria and mitochondria, there are two known canonical natural inhibitor proteins, namely the ε and IF1 subunits. These proteins regulate the CCW F1 FO -ATPase activity by blocking γ subunit rotation at the αDP /βDP /γ subunit interface in the F1 domain...
September 28, 2018: Journal of Bioenergetics and Biomembranes
Chunyan Liang, Chen Zhan, Fanyu Zeng, Dandan Xu, Yong Wang, Weiwei Zhao, Jiaheng Zhang, Jinhong Guo, Huanhuan Feng, Xing Ma
There are two main aspects of environmental governance including monitoring and remediation, both of which are essential for environmental protection. Self-propelled micro/nanomotors (MNM) have shown promising potential for achieving on-demand tasks in environmental field, including environmental sensing and pollutant removal or degradation. However, most of the current MNM used in environmental protection can hardly accomplish the two major tasks of both monitoring and pollutant degradation. Hereby, we present a bubble-propelled mesoporous silica-coated titania (TiO2@mSiO2) bilayer tubular micro-motor with platinum (Pt) and magnetic Fe3O4 nanoparticles modified on their inner walls...
September 24, 2018: ACS Applied Materials & Interfaces
Wenjuan Liu, Hongbin Ge, Zhongwei Gu, Xiaolong Lu, Jinxing Li, Joseph Wang
Artificial micro/nanomotors that could perform diverse tasks autonomously at the micro/nanoscale have been emerging as promising tools in many practical applications. Electrochemical synthesis is one of the dominating methods to fabricate these micro/nanodevices with diverse geometries and material components. By changing the conditions of electrochemical deposition, the surface morphology, crystal structure, and hence the resultant performance of deposited material could be tailored. In the current work, a feasible fabrication strategy is presented in terms of three unique electrodeposition types (i...
September 21, 2018: Small
Lilia Colina-Tenorio, Alain Dautant, Héctor Miranda-Astudillo, Marie-France Giraud, Diego González-Halphen
Rotary ATPases are a family of enzymes that are thought of as molecular nanomotors and are classified in three types: F, A, and V-type ATPases. Two members (F and A-type) can synthesize and hydrolyze ATP, depending on the energetic needs of the cell, while the V-type enzyme exhibits only a hydrolytic activity. The overall architecture of all these enzymes is conserved and three main sectors are distinguished: a catalytic core, a rotor and a stator or peripheral stalk. The peripheral stalks of the A and V-types are highly conserved in both structure and function, however, the F-type peripheral stalks have divergent structures...
2018: Frontiers in Physiology
Daolin Wang, Changyong Gao, Wei Wang, Mengmeng Sun, Bin Guo, Hui Xie, Qiang He
The T-1000 liquid metal terminator, which can transform and self-repair, represents a dream for decades that robots can fundamentally change our daily life. Until now, some large-scale liquid metal machines have been developed. However, there is no report on nanoscaled liquid metal machines and their biomedical applications. We describe here a shape-transformable and fusible rodlike swimming liquid metal nanomachine, based on the biocompatible and transformable liquid metal gallium. These nanomachines were prepared by a pressure-filter-template technology, and the diameter and length could be controlled by adjusting the nanoporous templates, filter time, and pressure...
September 21, 2018: ACS Nano
Zexi Liang, Donglei Fan
Highly efficient and widely applicable working mechanisms that allow nanomaterials and devices to respond to external stimuli with controlled mechanical motions could make far-reaching impact to reconfigurable, adaptive, and robotic nanodevices. We report an innovative mechanism that allows multifold reconfiguration of mechanical rotation of semiconductor nanoentities in electric ( E ) fields by visible light stimulation. When illuminated by light in the visible-to-infrared regime, the rotation speed of semiconductor Si nanowires in E -fields can instantly increase, decrease, and even reverse the orientation, depending on the intensity of the applied light and the AC E -field frequency...
September 2018: Science Advances
Maria Jose Esplandiu, Kuan Zhang, Jordi Fraxedas, Borja Sepulveda, David Reguera
The development of effective autonomous micro- and nanomotors relies on controlling fluid motion at interfaces. One of the main challenges in the engineering of such artificial machines is the quest for efficient mechanisms to power them without using external driving forces. In the past decade, there has been an important increase of man-made micro- and nanomotors fueled by self-generated physicochemical gradients. Impressive proofs of concept of multitasking machines have been reported demonstrating their capabilities for a plethora of applications...
September 18, 2018: Accounts of Chemical Research
Jizhuang Wang, Ze Xiong, Jing Zheng, Xiaojun Zhan, Jinyao Tang
A micro/nanomotor (MNM), as miniaturized machinery, can potentially bridge the application gap between the traditional macroscale motor and the molecular motor to manipulate materials at the cellular scale. The fascinating biomedical potential application for these tiny robots has been long envisioned by science fiction, such as "Fantastic Voyage", where complicated surgery can be performed at single cell precision without any surgical incision. However, to enter the highly conservative biomedical and healthcare industry in practice, the MNM must provide unique advantages over existing technology without introducing additional health risk, which has not been fully materialized...
September 18, 2018: Accounts of Chemical Research
Isamar Ortiz-Rivera, Motilal Mathesh, Daniela A Wilson
Autonomous micro- and nanoscale systems have revolutionized the way scientists look into the future, opening up new frontiers to approach and solve problems via a more bioinspired route. However, to achieve systems with higher complexity, superior output control, and multifunctionality, an in-depth study of the different factors that affect micro- and nanomotor behavior is crucial. From a fundamental perspective, the mechanical response of micro- and nanomotors still requires further study in order to have a better understanding of how exactly these systems operate and the different mechanisms of motion that can be combined into one system to achieve an optimal response...
September 18, 2018: Accounts of Chemical Research
Yingjie Wu, Tieyan Si, Changyong Gao, Mingcheng Yang, Qiang He
We report a hollow dumbbell-shaped manganese dioxide (MnO2 ) colloidal kayaker capable of converting a pair of breathing oxygen bubbles into self-propelled movement. The bubble pair generated by catalytic decomposition of hydrogen peroxide fuel grew either synchronously or asynchronously, driving the colloidal kayaker to move along a fluctuating circle. The synchronous or asynchronous breathing mode of bubble pair is governed by the asymmetric catalytic sites of the colloidal kayakers. This imbalanced distribution of bubble propulsion force generates the driving force and the centripetal force on the colloidal kayaker...
September 26, 2018: Journal of the American Chemical Society
Jan-Philipp Günther, Michael Börsch, Peer Fischer
Self-propelled chemical motors are chemically powered micro- or nanosized swimmers. The energy required for these motors' active motion derives from catalytic chemical reactions and the transformation of a fuel dissolved in the solution. While self-propulsion is now well established for larger particles, it is still unclear if enzymes, nature's nanometer-sized catalysts, are potentially also self-powered nanomotors. Because of its small size, any increase in an enzyme's diffusion due to active self-propulsion must be observed on top of the enzyme's passive Brownian motion, which dominates at this scale...
September 18, 2018: Accounts of Chemical Research
Renfeng Dong, Yuepeng Cai, Yiran Yang, Wei Gao, Biye Ren
Synthetic micro/nanomotors (MNMs) are a particular class of micrometer or nanometer scale devices with controllable motion behavior in solutions by transferring various energies (chemical, optical, acoustic, magnetic, electric, etc.) into mechanical energy. These tiny devices can be functionalized either chemically or physically to accomplish complex tasks in a microcosm. Up to now, MNMs have exhibited great potential in various fields, ranging from environmental remediation, nanofabrication, to biomedical applications...
September 18, 2018: Accounts of Chemical Research
Mingjun Xuan, Jingxin Shao, Changyong Gao, Wei Wang, Luru Dai, Qiang He
We report a near-infrared (NIR) light-powered Janus mesoporous silica nanomotor (JMSNM) with macrophage cell membrane (MPCM) cloaking that can actively seek cancer cells and thermomechanically percolate cell membrane. Upon exposure to NIR light, a heat gradient across the Janus boundary of the JMSNMs is generated by the photothermal effect of the Au half-shells, resulting in a self-thermophoretic force that propels the JMSNMs. In biological medium, the MPCM camouflaging can not only prevent dissociative biological blocks from adhering to JMSNMs but also improve the seeking sensitivity of the nanomotors by specifically recognizing cancer cells...
September 17, 2018: Angewandte Chemie
Liqiang Ren, Wei Wang, Thomas E Mallouk
Engines and motors are everywhere in the modern world, but it is a challenge to make them work if they are very small. On the micron length scale, inertial forces are weak and conventional motor designs involving, e.g., pistons, jets, or flywheels cease to function. Biological motors work by a different principle, using catalysis to convert chemical to mechanical energy on the nanometer length scale. To do this, they must apply force continuously against their viscous surroundings, and because of their small size, their movement is "jittery" because of the random shoves and turns they experience from molecules in their surroundings...
September 18, 2018: Accounts of Chemical Research
Yongxiang Gao, Roel P A Dullens, Dirk G A L Aarts
Colloidal particles with asymmetric catalytic activities are emerging micro/nanomotors that harvest chemical energy for propulsion in fluids. It is of general interest to produce such particles with high performance, in large quantity and at low cost. In this paper, we present a facile bulk method to synthesize silver-head colloidal silica rods. These particles self-propel towards their active sites by reacting with hydrogen peroxide, and the velocity is tuned via the fuel concentration. We show that these motors are highly efficient; compared to the currently available chemical-phoretic micro/nanomotors they show similar performance of self-propulsion at fuel concentrations that are two orders of magnitude smaller...
September 11, 2018: Soft Matter
Dekai Zhou, Yuan Gao, Junjie Yang, Yuguang C Li, Guangbin Shao, Guangyu Zhang, Tianlong Li, Longqiu Li
It is of great interest and big challenge to control the collective behaviors of nanomotors to mimic the aggregation/separation behavior of biological systems. Here, a light-acoustic combined method is proposed to control the aggregation/separation of artificial nanomotors. It is shown that nanomotors aggregate at the pressure node in acoustic field and afterward present a collective "firework" separation behavior induced by light irradiation. The collective behavior is found to be applicable for metallic materials and polymers even different light wavelengths are used...
July 2018: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Sanae Benabou, Cyril Ruckebusch, Michel Sliwa, Anna Aviñó, Ramon Eritja, Raimundo Gargallo, Anna de Juan
The i-motif is a DNA structure formed by cytosine-rich sequences, very relevant from a biochemical point of view and potentially useful in nanotechnology as pH-sensitive nanodevices or nanomotors. To provide a different view on the structural changes and dynamics of direct excitation processes involving i-motif structures, the use of rapid-scan FTIR spectroscopy is proposed. Hybrid hard- and soft-modelling based on the Multivariate Curve Resolution by Alternating Least Squares (MCR-ALS) algorithm has been used for the resolution of rapid-scan FTIR spectra and the interpretation of the photochemically induced time-dependent conformational changes of i-motif structures...
July 25, 2018: Physical Chemistry Chemical Physics: PCCP
Daniel Andrén, Pawel Karpinski, Mikael Käll
The possibility to generate and measure rotation and torque at the nanoscale is of fundamental interest to the study and application of biological and artificial nanomotors and may provide new routes towards single cell analysis, studies of non-equilibrium thermodynamics, and mechanical actuation of nanoscale systems. A facile way to drive rotation is to use focused circularly polarized laser light in optical tweezers. Using this approach, metallic nanoparticles can be operated as highly efficient scattering-driven rotary motors spinning at unprecedented rotation frequencies in water...
June 30, 2018: Journal of Visualized Experiments: JoVE
Rahul Salunke, Tobias Mourier, Manidipa Banerjee, Arnab Pain, Dhanasekaran Shanmugam
The mitochondrial F-type ATP synthase, a multisubunit nanomotor, is critical for maintaining cellular ATP levels. In T. gondii and other apicomplexan parasites, many subunit components necessary for proper assembly and functioning of this enzyme appear to be missing. Here, we report the identification of 20 novel subunits of T. gondii F-type ATP synthase from mass spectrometry analysis of partially purified monomeric (approximately 600 kDa) and dimeric (>1 MDa) forms of the enzyme. Despite extreme sequence diversification, key FO subunits a, b, and d can be identified from conserved structural features...
July 2018: PLoS Biology
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