Read by QxMD icon Read


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 19, 2018: Biochimica et Biophysica Acta
Shauni Keller, Serena P Teora, Guo Xun Hu, Marlies Nijemeisland, Daniela Apreutesei Wilson
Micro- and nanomotors and their use for biomedical applications have received recently 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 asymmetric hydrogel microparticle with autonomous movement using a microfluidic chip generating asymmetric aqueous two-phase separating droplets consisting of 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 7, 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 Arque, Albert Miguel-López, Anita Jannasch, Tom Stumpp, Erik Schäffer, Lorenzo Albertazzi, Samuel Sanchez
The use of enzyme catalysis to power micro and nanomachines offers unique features such as biocompatibility, versatili-ty 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 mo-tion. Two different micromotor architectures based on either polystyrene (PS) or polystyrene coated with a rough silicon dioxide shell (PS@SiO2) were explored...
May 22, 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
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...
July 1, 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...
March 21, 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 ...
April 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 H2 O2 decomposition and exhibit enhanced diffusion that depends on fuel concentration, consistent with their chemical propulsion.
February 15, 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 F1 FO -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 F1 FO -ATPase of Paracoccus denitrificans (PdF1 FO ), 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
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"