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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 media, 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...
August 9, 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...
August 6, 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...
July 20, 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
Jemish Parmar, Diana Vilela, Katherine Villa, Joseph Wang, Samuel Sánchez
The quest to provide clean water to the entire population has led to a tremendous boost in the development of environmental nanotechnology. Toward this end, micro/nanomotors are emerging as attractive tools to improve the removal of various pollutants. The micro/nanomotors either are designed with functional materials in their structure or are modified to target pollutants. The active motion of these motors improves the mixing and mass transfer, greatly enhancing the rate of various remediation processes. Their motion can also be used as an indicator of the presence of a pollutant for sensing purposes...
August 1, 2018: Journal of the American Chemical Society
Apabrita Mallick, Soumyajit Roy
Visible light propelled nanomotors are a class of highly sought after active matter. Here we report a gold decorated semiconductor and a soft-oxometalate based TiO2-{Mo7}-Au nanomotor which can be propelled diffusiophoretically on exposure to visible light and show excellent photocatalytic activity. These systems exclude the use of any harsh toxic chemical as fuel and exhibit a speed of 10 μm s-1 in water. Their motion can also be controlled by rapid switching of light. We use these photocatalytic nanomotors for environmental cleansing as they can facilitate the removal of organic pollutants from water under visible light...
July 9, 2018: Nanoscale
Hendrik Sielaff, Thomas M Duncan, Michael Börsch
F-type ATP synthases are extraordinary multisubunit proteins that operate as nanomotors. The Escherichia coli (E. coli) enzyme uses the proton motive force (pmf) across the bacterial plasma membrane to drive rotation of the central rotor subunits within a stator subunit complex. Through this mechanical rotation, the rotor coordinates three nucleotide binding sites that sequentially catalyze the synthesis of ATP. Moreover, the enzyme can hydrolyze ATP to turn the rotor in the opposite direction and generate pmf...
June 20, 2018: Biochimica et Biophysica Acta
Shauni Keller, Serena P Teora, Guo Xun Hu, Marlies Nijemeisland, Daniela A Wilson
Micro- and nanomotors and their use for biomedical applications have recently received increased attention. However, most designs use top-down methods to construct inorganic motors, which are labour-intensive and not suitable for biomedical use. Herein, we report a high-throughput design of an asymmetric hydrogel microparticle with autonomous movement by using a microfluidic chip to generate asymmetric, aqueous, two-phase-separating droplets consisting of poly(ethylene glycol) diacrylate (PEGDA) and dextran, with the biocatalyst placed in the PEGDA phase...
June 19, 2018: Angewandte Chemie
Mariel Zarco-Zavala, Francisco Mendoza-Hoffmann, José J García-Trejo
The ATP synthase is a reversible nanomotor that gyrates its central rotor clockwise (CW) to synthesize ATP and in counter clockwise (CCW) direction to hydrolyse it. In bacteria and mitochondria, two natural inhibitor proteins, namely the ε and IF1 subunits, prevent the wasteful CCW F1 FO -ATPase activity by blocking γ rotation at the αDP /βDP /γ interface of the F1 portion. In Paracoccus denitrificans and related α-proteobacteria, we discovered a different natural F1 -ATPase inhibitor named ζ. Here we revise the functional and structural data showing that this novel ζ subunit, although being different to ε and IF1 , it also binds to the αDP /βDP /γ interface of the F1 of P...
June 8, 2018: Biochimica et Biophysica Acta
Mohammad Zarei, Mohanna Zarei
Self-propelled micro/nanomotors have gained attention for successful application in cargo delivery, therapeutic treatments, sensing, and environmental remediation. Unique characteristics such as high speed, motion control, selectivity, and functionability promote the application of micro/nanomotors in analytical sciences. Here, the recent advancements and main challenges regarding the application of self-propelled micro/nanomotors in sensing and environmental remediation are discussed. The current state of micro/nanomotors is reviewed, emphasizing the period of the last five years, then their developments into the future applications for enhanced sensing and efficient purification of water resources are extrapolated...
June 7, 2018: Small
Heng Ye, Jian Kang, Guofeng Ma, Hongqi Sun, Shaobin Wang
Platinum (Pt) free micro/nanomotors (MNMs) using a low content of fuels are highly desired for many applications. Herein, we demonstrate that cathodic electrofabrication can produce modified MnO2 based microtubes and microrods as highly efficient MNMs in hydrogen peroxide (H2 O2 ) as low as 0.2%. The speed of graphene/Ag-MnO2 micromotors could be smartly regulated using a surfactant and the maximum speed of an individual micromotor exceeds 1.3 mm s-1 in 0.5% H2 O2 . The propelling force and output power of the micromotors are 3...
May 25, 2018: Journal of Colloid and Interface Science
Alejandro Baeza, María Vallet-Regí
The development of nanomachines able to operate at the nanoscale, performing complex tasks such as drug delivery, precision surgery, or cell detection, constitutes one of the most important challenges in nanotechnology. The principles that rule the nanoscale are completely different from the ones which govern the macroscopic world and, therefore, the collaboration of scientists with expertise in different fields is required for the effective fabrication of these tiny machines. In this review, the most recent advances carried out in the synthesis and application of nanomachines for diagnosis applications will be presented in order to provide a picture of their potential in the detection of important biomolecules or pathogens in a selective and controlled manner...
May 25, 2018: International Journal of Molecular Sciences
Tania Patiño, Natalia Feiner-Gracia, Xavier Arqué, Albert Miguel-López, Anita Jannasch, Tom Stumpp, Erik Schäffer, Lorenzo Albertazzi, Samuel Sánchez
The use of enzyme catalysis to power micro- and nanomachines offers unique features such as biocompatibility, versatility, and fuel bioavailability. Yet, the key parameters underlying the motion behavior of enzyme-powered motors are not completely understood. Here, we investigate the role of enzyme distribution and quantity on the generation of active motion. Two different micromotor architectures based on either polystyrene (PS) or polystyrene coated with a rough silicon dioxide shell (PS@SiO2 ) were explored...
June 27, 2018: Journal of the American Chemical Society
Apabrita Mallick, Abhrajit Laskar, R Adhikari, Soumyajit Roy
The recent interest in self-propulsion raises an immediate challenge in facile and single-step synthesis of active particles. Here, we address this challenge and synthesize soft oxometalate nanomotors that translate ballistically in water using the energy released in a redox reaction of hydrazine fuel with the soft-oxometalates. Our motors reach a maximum speed of 370 body lengths per second and remain motile over a period of approximately 3 days. We report measurements of the speed of a single motor as a function of the concentration of hydrazine...
2018: Frontiers in Chemistry
Mohamed Shehata Draz, Nivethitha Kota Lakshminaraasimulu, Sanchana Krishnakumar, Dheerendranath Battalapalli, Anish Vasan, Manoj Kumar Kanakasabapathy, Aparna Sreeram, Shantanu Kallakuri, Prudhvi Thirumalaraju, Yudong Li, Stephane Hua, Xu G Yu, Daniel R Kuritzkes, Hadi Shafiee
Zika virus (ZIKV) infection is an emerging pandemic threat to humans that can be fatal in newborns. Advances in digital health systems and nanoparticles can facilitate the development of sensitive and portable detection technologies for timely management of emerging viral infections. Here we report a nanomotor-based bead-motion cellphone (NBC) system for the immunological detection of ZIKV. The presence of virus in a testing sample results in the accumulation of platinum (Pt)-nanomotors on the surface of beads, causing their motion in H2 O2 solution...
May 16, 2018: ACS Nano
Hua Su, Yimin Fang, Fangyuan Chen, Wei Wang
The capability of semiconductor nanomaterials to convert solar energy to chemical energy has led to many promising applications, for instance, photocatalyzed H2 generation. Studying this important photocatalytic reaction at the single nanocatalyst level provides a great opportunity to understand the microscopic reaction kinetics and mechanism by overcoming the chemical and structural heterogeneity among individuals. Here we report a fluorescence (FL) labeling strategy to visualize individual H2 nanobubbles that are generated at single CdS nanoparticles during photocatalysis...
February 14, 2018: Chemical Science
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...
May 3, 2018: Chemical Communications: Chem Comm
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