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Quantum biology

Xiao Hu, Chenbo Dong, Rigu Su, Quan Xu, Cerasela Zoica Dinu
The next generation of nanowires that could advance the integration of functional nanosystems into synthetic applications from photocatalysis to optical devices need to demonstrate increased ability to promote electron transfer at their interfaces while ensuring optimum quantum confinement. Herein we used the biological recognition and the self-assembly properties of tubulin, a protein involved in building the filaments of cellular microtubules, to create stable, free standing and conductive sulfur-doped carbon nanodots-based conductive bio-hybrids...
December 6, 2016: Scientific Reports
Anusuya Banerjee, Thomas Pons, Nicolas Lequeux, Benoit Dubertret
Semiconductor nanoparticles particularly quantum dots (QDs) are interesting alternatives to organic fluorophores for a range of applications such as biosensing, imaging and therapeutics. Addition of a programmable scaffold such as DNA to QDs further expands the scope and applicability of these hybrid nanomaterials in biology. In this review, the most important stages of preparation of QD-DNA conjugates for specific applications in biology are discussed. Special emphasis is laid on (i) the most successful strategies to disperse QDs in aqueous media, (ii) the range of different conjugation with detailed discussion about specific merits and demerits in each case, and (iii) typical applications of these conjugates in the context of biology...
December 6, 2016: Interface Focus
Hong-Wei Yu, Jing-Hui Jiang, Ze Zhang, Guang-Cai Wan, Zhi-Yong Liu, Dong Chang, Hong-Zhi Pan
The assembly of quantum dots (QDs) in a simply method opens up opportunities to obtain access to the full potential of assembled QDs by virtue of the collective properties of the ensembles. In this study, quantum dots CdTe and graphene (Gr) nanocomposite was constructed for the simultaneous determination of uric acid (UA) and dopamine (DA). The CdTe QDs-Gr nanocomposite was prepared by ultrasonication and was characterized with microscopic techniques. The nanocomposite modified electrode was characterized by cyclicvoltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS)...
December 2, 2016: Analytical Biochemistry
John F Barry, Matthew J Turner, Jennifer M Schloss, David R Glenn, Yuyu Song, Mikhail D Lukin, Hongkun Park, Ronald L Walsworth
Magnetic fields from neuronal action potentials (APs) pass largely unperturbed through biological tissue, allowing magnetic measurements of AP dynamics to be performed extracellularly or even outside intact organisms. To date, however, magnetic techniques for sensing neuronal activity have either operated at the macroscale with coarse spatial and/or temporal resolution-e.g., magnetic resonance imaging methods and magnetoencephalography-or been restricted to biophysics studies of excised neurons probed with cryogenic or bulky detectors that do not provide single-neuron spatial resolution and are not scalable to functional networks or intact organisms...
November 22, 2016: Proceedings of the National Academy of Sciences of the United States of America
Subrahmanyam Sappati, Ali Hassanali, Ralph Gebauer, Prasenjit Ghosh
Ellipticine is a natural product that is currently being actively investigated for its inhibitory cancer and HIV properties. Here we use path-integral molecular dynamics coupled with excited state calculations to characterize the role of nuclear quantum effects on the structural and electronic properties of ellipticine in water, a common biological solvent. Quantum effects collectively enhance the fluctuations of both light and heavy nuclei of the covalent and hydrogen bonds in ellipticine. In particular, for the ellipticine-water system, where the proton donor and acceptor have different proton affinities, we find that nuclear quantum effects (NQEs) strengthen both the strong and the weak H bonds...
November 28, 2016: Journal of Chemical Physics
Przemysław Krawczyk, Beata Jędrzejewska, Marek Pietrzak, Tomasz Janek
In this study, the newly synthesized 4'-(1H-phenantro[9,10-d]-imidazol-2-yl)-bifenyl-4-carboaldehyde - PB2 was investigated as a fluorescent dye. For this reason, the spectroscopic properties in solvents of different polarity were studied. The experimental data were supported by quantum-chemical calculations using density functional theory. Measurements and theoretical calculations showed that PB2 compound is characterized by the non-monotonic solvatochromism, strongly polar charge transfer excited state, large Stokes' shift, high fluorescence quantum yield and high fluorescence lifetime...
November 8, 2016: Journal of Photochemistry and Photobiology. B, Biology
Jing-Hui Zhang, Aping Niu, Jing Li, Jian-Wei Fu, Qun Xu, De-Sheng Pei
Carbon quantum dots (CDs) were widely investigated because of their tunable fluorescence properties and low toxicity. However, so far there have been no reports on in vivo functional studies of hair and skin derived CDs. Here, hair derived CDs (HCDs) and skin derived CDs (SCDs) were produced by using human hair and pig skin as precursors. The quantum yields (QYs) of HCDs and SCDs were quite high, compared to citric acid derived CDs (CCDs). HCDs and SCDs possess optimal photostability, hypotoxicity and biocompatibility in zebrafish, indicating that HCDs and SCDs possess the capacity of being used as fluorescence probes for in vivo biological imaging...
November 25, 2016: Scientific Reports
Robert W Smith, Britta Helwig, Adrie H Westphal, Eran Pel, Maximilian Hörner, Hannes M Beyer, Sophia L Samodelov, Wilfried Weber, Matias D Zurbriggen, Jan Willem Borst, Christian Fleck
BACKGROUND: Obtaining accurate estimates of biological or enzymatic reaction rates is critical in understanding the design principles of a network and how biological processes can be experimentally manipulated on demand. In many cases experimental limitations mean that some enzymatic rates cannot be measured directly, requiring mathematical algorithms to estimate them. Here, we describe a methodology that calculates rates at which light-regulated proteins switch between conformational states...
November 25, 2016: BMC Systems Biology
Xiaomin Fu, Xingrong Tan, Ruo Yuan, Shihong Chen
A novel dual-potential ratiometric electrochemiluminescence (ECL) sensor was designed for detecting dopamine (DA) based on graphene-CdTe quantum dots (G-CdTe QDs) as the cathodic emitter and self-enhanced Ru(II) composite (TAEA-Ru) as the anodic emitter. TAEA-Ru was prepared by linking ruthenium(II) tris(2,2'-bipyridyl-4,4'-dicarboxylato) with tris(2-aminoethyl)amine. Firstly, 3-aminopropyltriethoxysilane founctionalized G-CdTe QDs was used as the substrate for capturing target DA via the specific recognition of the diol of DA to the oxyethyl group of APTES...
November 11, 2016: Biosensors & Bioelectronics
Arif Gulzar, Piaoping Yang, Fei He, Jiating Xu, Dan Yang, Liangge Xu, Mohammad Omar Jan
Graphene has distinctive mechanical, electronic, and optical properties, which researchers have applied to develop innovative electronic materials including transparent conductors and ultrafast transistors. Lately, the understanding of various chemical properties of graphene has expedited its application in high-performance devices that generate and store energy. Graphene is now increasing its terrain outside electronic and chemical applications toward biomedical areas such as precise bio sensing through graphene-quenched fluorescence, graphene-enhanced cell differentiation and growth, and graphene-assisted laser desorption/ionization for mass spectrometry...
November 19, 2016: Chemico-biological Interactions
Guoxing Lin
Anomalous diffusion exists widely in polymer and biological systems. Pulsed-field gradient (PFG) techniques have been increasingly used to study anomalous diffusion in nuclear magnetic resonance and magnetic resonance imaging. However, the interpretation of PFG anomalous diffusion is complicated. Moreover, the exact signal attenuation expression including the finite gradient pulse width effect has not been obtained based on fractional derivatives for PFG anomalous diffusion. In this paper, a new method, a Mainardi-Luchko-Pagnini (MLP) phase distribution approximation, is proposed to describe PFG fractional diffusion...
November 21, 2016: Journal of Chemical Physics
Riccardo Frisenda, Vera A E C Janssen, Ferdinand C Grozema, Herre S J van der Zant, Nicolas Renaud
Recent observations of destructive quantum interference in single-molecule junctions confirm the role of quantum effects in the electronic conductance properties of molecular systems. These effects are central to a broad range of chemical and biological processes and may be beneficial for the design of single-molecule electronic components to exploit the intrinsic quantum effects that occur at the molecular scale. Here we show that destructive interference can be turned on or off within the same molecular system by mechanically controlling its conformation...
December 2016: Nature Chemistry
Hong Hee Kim, Joon-Suh Park, Il Ki Han, Sung Ok Won, Cheolmin Park, Do Kyung Hwang, Won Kook Choi
Colloidal quantum dots (QDs) have been extensively studied for optoelectronic and biological applications due to their unique physical and optical properties. In particular, among the optoelectronics applications, the white light emitting diode (WLED) has great potential in flat panel displays and solid-state lighting. Herein, we demonstrate a novel, facile, and efficient technique for the synthesis of CdTe/ZnO/GO quasi-core-shell-shell hybrid quantum dots containing the CdTe core with multi shells of ZnO and graphene oxide (GO) and fabrication of WQDLEDs...
December 1, 2016: Nanoscale
Ilseung Yang, Jong Woo Lee, Sunjin Hwang, Jung Eun Lee, Eunhak Lim, June Lee, Doyk Hwang, Clara H Kim, Young-Sam Keum, Seong Keun Kim
We synthesized a new organic fluorescent dye named resveratrone glucoside from the photoreaction of naturally-occurring phytoalexin compound resveratrol glucoside (resveratrol-3-β-mono-d-glucoside), which is abundant in various plants such as berries, herbs, nuts and grapes. Just like its predecessor molecule resveratrone that was previously discovered by our group, resveratrone glucoside possesses excellent optical properties including a high fluorescence quantum yield, a large Stokes' shift, and a large two-photon absorption cross section...
November 12, 2016: Journal of Photochemistry and Photobiology. B, Biology
Ievgen Shulov, Roman V Rodik, Youri Arntz, Andreas Reisch, Vitaly I Kalchenko, Andrey S Klymchenko
The key challenge in the field of fluorescent nanoparticles (NPs) for biological applications is to achieve superior brightness for sizes equivalent to single proteins (3-7 nm). We propose a concept of shell-cross-linked fluorescent micelles, in which PEGylated cyanine 3 and 5 bis-azides form a covalently attached corona on micelles of amphiphilic calixarene bearing four alkyne groups. The fluorescence quantum yield of the obtained monodisperse NPs, with a size of 7 nm, is a function of viscosity and reached up to 15 % in glycerol...
November 16, 2016: Angewandte Chemie
Fang Liu, Shujia Li, Ruoxin Hu, Na Shao
Core-shell structured quantum dot (QD)-silica fluorescent nanoparticles have attracted a great deal of attention due to the excellent optical properties of QDs and the stability of silica. In this study, core-shell structured CdTe/CdS@SiO2 @CdTe@SiO2 fluorescent nanospheres were synthesized based on the Stöber method using multistep silica encapsulation. The second silica layer on the CdTe QDs maintained the optical stability of nanospheres and decreased adverse influences on the probe during subsequent processing...
November 18, 2016: Luminescence: the Journal of Biological and Chemical Luminescence
Sebastian Kuhlgert, Greg Austic, Robert Zegarac, Isaac Osei-Bonsu, Donghee Hoh, Martin I Chilvers, Mitchell G Roth, Kevin Bi, Dan TerAvest, Prabode Weebadde, David M Kramer
Large-scale high-throughput plant phenotyping (sometimes called phenomics) is becoming increasingly important in plant biology and agriculture and is essential to cutting-edge plant breeding and management approaches needed to meet the food and fuel needs for the next century. Currently, the application of these approaches is severely limited by the availability of appropriate instrumentation and by the ability to communicate experimental protocols, results and analyses. To address these issues, we have developed a low-cost, yet sophisticated open-source scientific instrument designed to enable communities of researchers, plant breeders, educators, farmers and citizen scientists to collect high-quality field data on a large scale...
October 2016: Royal Society Open Science
Nedjoua Drici, Mohamed Abdelghani Krallafa
Metal-ligand interactions give rise to a wide variety of metal complexes with various physical properties and chemical behaviours and numerous practical applications. The ability of the zinc ion to enhance the structural stability of many proteins by electrostatic interactions or by co-ordination with surrounding amino acids makes it the most important metal ion found in biological systems. In this paper, we highlight the importance of non-covalent interaction established between a metal ion and its environment in stabilizing biomolecules...
November 15, 2016: Journal of Biological Inorganic Chemistry: JBIC
Maria Cristina Lo Giudice, Luciana M Herda, Ester Polo, Kenneth A Dawson
Nanoparticles interacting with, or derived from, living organisms are almost invariably coated in a variety of biomolecules presented in complex biological milieu, which produce a bio-interface or 'biomolecular corona' conferring a biological identity to the particle. Biomolecules at the surface of the nanoparticle-biomolecule complex present molecular fragments that may be recognized by receptors of cells or biological barriers, potentially engaging with different biological pathways. Here we demonstrate that using intense fluorescent reporter binders, in this case antibodies bound to quantum dots, we can map out the availability of such recognition fragments, allowing for a rapid and meaningful biological characterization...
November 15, 2016: Nature Communications
Mina Mehrzad-Samarin, Farnoush Faridbod, Amin Shiralizadeh Dezfuli, Mohammad Reza Ganjali
A novel optical nanosensor for detection of Metronidazole in biological samples was reported. Graphene quantum dots embedded silica molecular imprinted polymer (GQDs-embedded SMIP) was synthesized and used as a selective fluorescent probe for Metronidazole detection. The new synthesized GQDs-embedded SMIP showed strong fluorescent emission at 450nm excited at 365nm which quenched in presence of Metronidazole as a template molecule.. The quenching was proportional to the concentration of Metronidazole in a linear range of at least 0...
October 20, 2016: Biosensors & Bioelectronics
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