Mono-dispersed multi-doped LiFePO4/C nanoparticles as a cathode material for
lithium-ion batteries
doi: https://doi.org/10.13052/jsame2245-4551.2018032
Wanmin Liu1,2, Zhengjun Fang1,2, Ru Zhang1,2, Qiang Tao1,2,
Bianling Zhang1, Donghong Yu2 and Yuanzheng Yue2
1College of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China
2Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
Abstract: [+] | Download File [ 693KB ] | Read Article Online
Abstract: Ni-Co-Mn doped LiFePO4/C has been prepared from the spent electroless nickel plating bath, ferrous oxalate and lithium carbonate. A plausible formation mechanism of the multi-doped LiFePO4/C is proposed. XRD and Rietveld refinement confirm that Ni, Co and Mn have been successfully incorporated in the LiFePO4/C crystal. SEM and laser particle size analyses verify that the material synthesized at 700∘C for 10 h consists of narrow-distribution mono-dispersed grape-like nanoparticles. The charge-discharge tests demonstrate that the material delivers initial discharge specific capacities of 167.5, 152.3 and 116.8 mAh⋅g-1 at 0.2 C, with the capacity retentions of 99.7%, 99.0% and 98.9% after 50 cycles at 25, 0 and -20∘C, respectively.
Screening for functional peptide based SsGPRC6A to recognize L-amino
acids specifically by molecular docking and dynamics simulation
doi: https://doi.org/10.13052/jsame2245-4551.2018031
Ru Zhang1,2, Zhengjun Fang1,2, Wanmin Liu1,2, Bianling Zhang1, Qiang Tao1,2, and Donghong Yu2,3
1College of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China
2Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
3Sino-Danish Center for Education and Research (SDC), Aarhus, 8000, Denmark
Abstract: [+] | Download File [ 91KB ] | Read Article Online
Abstract: One of the most important function of G protein-coupled receptors family C subtype 6A
(GPRC6A) recognizes and responds to L-amino acids as its principal physiological ligand. In
this study, homology modeling, molecular docking and molecular dynamics simulation were
performed to explore structural features and binding mechanism of L-amino acids on
SsGPRC6A of Sus scrofa, and to construct model containing the binding domain of the
ligands for searching functional and special polypeptide to recognize the L-amino acids
respectively. The homology model of SsGPRC6A was constructed using the crystal structure
of the extracellular region of the group II metabotropic glutamate receptor (2E4U) at 2.35 Ã…
resolution as template.
Effects of Remote Substituents on Electrochemical Reduction of
X-PhCH=NPhCH=CHPh-Y
doi: https://doi.org/10.13052/jsame2245-4551.2018030
Zhengjun Fang1,2, Ru Zhang1,2, Wanmin Liu1,2, Qiang Tao1,2, Bianlin Zhang1 and Donghong Yu2,3
1Hunan Provincial Key Laboratory of Environmental Catalysis & Waste Recycling, School of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China
2Department of Chemistry and Bioscience, Aalborg University,
Aalborg 9220, Denmark
3Sino-Danish Center for Education and Research (SDC), Aarhus, 8000, Denmark
Abstract: [+] | Download File [ 148KB ] | Read Article Online
Abstract: Schiff-bases have prospective applications in functional technologies such as organic
photovoltaic [1] and other molecular electronic devices [2]. Therefore, for the design of
molecular optoelectronic devices of high efficiency, it is hence of great interest and
significance to understand the relationship between structure and electrochemical property of
Schiff bases in the molecular level [3]. However, Schiff base displays a high degree of
complexity that makes it difficult and expensive to elaborate this in a large scale.
Consequently, quantitative structure-property relationship (QSPR) focusing on simple, costeffective
and easily scalable Schiff bases has emerged [4].
Abstract: In the last two decades a wide range of nanofabrication approaches have been developed
based on top down lithography or bottom up self assembly. Here approaches based on
colloidal monolayer masks combined with cleanroom processing such as Sparse Colloidal
Lithography (SCL) [1] and Hole Mask Colloidal Lithography (HMCL) [2] will be presented.
Traditionally these approaches have given arrays of circularly symmetric structures such as
disks [3], holes [4], rings [5] and cones [2]. More recent approaches have allowed postmodification
of the masks to change their size [6] or their shape. Colloidal lithography
approaches have proven appropriate to allow arrays of novel plasmonic structures to be
fabricated to study plasmon coupling [7], refractive index sensitivity [8] and chiral properties
of arrays [9].
Abstract: Class 2 CRISPR (clustered regularly interspaced short
palindromic repeats) systems offer a unique protocol for
genome editing in eukaryotic cells and has already been
validated in many organisms [1]. In genome editing
through CRISPR, the target DNA is first recognized by a
complementary RNA bound to an endonuclease. The
RNA-guided DNA unwinding leads to formation of a
RNA-DNA hybrid duplex and a displaced DNA strand
(Figure 1) . Thereafter, the nuclease portion of the Cas9
protein closest to the DNA cleavage site attains a
conformation essential for concerted DNA cutting.
Abstract: Natural materials often display hierarchical organization of nano-structures, lending unique
properties to the macroscopic material. Many proteins are able to self-assemble into ordered
nano/micro-structures, and it is interesting to investigate applications of such structures in
materials science. However, for many applications it is desirable to have additional
functionality, not present in the original protein. It is therefore desirable to develop
methodology for functionalization of protein materials. We have developed novel techniques
for preparation of functionalized protein materials. One extremely flexible and facile method
involves co-grinding of a protein with a hydrophobic material. Upon exposure to appropriate
stimuli the composite undergoes self-assembly into functionalized fibrils. The process can be
performed simply with mortar and pestle [1-3] or with automated milling equipment [4].
These fibrils can then be induced to undergo colloidal assembly into materials. In this
presentation will be given examples of such materials preparation, and applications of the
materials in photonics and bioelectronics will be presented.
Abstract: The photophysics of dyes strongly depends on their microenvironment, either solvent
molecules or nearby charges. Also interactions with other dyes affect the spectroscopical
properties. For ionic dyes it can be difficult to quantify the interactions due to solvent screening
and/or nearby counter ions. To shed light on intrinsic properties, it is advantageous to perform
luminescence experiments in the gas phase, which, however, requires specialized apparatus. In
Aarhus we have constructed the LUNA setup, LUminescence iNstrument in Aarhus (Figure 1)
[1] that allows us to measure fluorescence from larger ions produced by electrospray ionization.
We used this setup to study rhodamine monomer cations as well as homodimers where the two
dye cations are separated by methylene linkers, (CH2)n. I will present the results and compare
to spectra measured in solution. Indeed, in the gas phase, we measure significant redshifted
emission when there is a nearby charge while in solution solvent screening reduces this effect
to almost nothing. The impact of nearby charges may have implications for gas-phase Förster
Resonance Energy Transfer experiments where the aim is to reveal the structures of
biomolecular ions in the gas phase.
Abstract: We present a detailed analysis of the kinetics of electron transfer at a solid-solid interface. The
study was enabled by measuring the conductance of ultra-thin (< 50 nm), fully suspended
single-crystalline silicon nanowires with several well-defined surface chemistries [1]. The
measurement had a dynamic range across 7 orders of magnitude with a detection sensitivity of
order single event over a 103 μm2 reaction area. We find that classic, first-order process [2, 3]
is unable to capture the reaction progress and propose a new kinetic model based on a
continuum of reactant geometries inherently present at typical solid-solid interfaces. The new
model captures the kinetic manifestation of heterogeneity in a single, global rate constant.
Quantitative agreement with data and an analysis of the parameters suggest that this model may
be generally applicable to charge transfer at solid-solid interfaces.
Abstract: A central goal in molecular electronics is to understand charge transport properties of single
molecules and their ensembles. This fundamental knowledge may ultimately pave the way
for electronic components constructed from tailor-made molecular building-blocks that can
overcome some limits of conventional silicon-based microelectronics. The formation of
robust and reproducible contact between molecule and electrode is a key challenge. At the
single-molecule level, we have recently explored the use of parallel self-assembly strategies
towards the formation of multiple single-molecule junctions, wherein the molecule-electrode
interface is controlled with atomic precision [1]. However, the use of self-assembled
monolayers (SAMs) offer a complementary approach for fabricating molecular electronic
devices that are more amenable to device integration and up-scaling.
Abstract: In this paper the optics of single and coupled 3D metal nanorods in solution is considered
theoretically using the Electric-Field Integral Equation (EFIE) [1]. The extinction, scattering,
and absorption cross section spectra, and field enhancement distributions, will be presented at
the conference for a range of single rod geometries, and for configurations of rods with e.g.
varying lengths and separation.
Abstract: Plasmonic nanostructures are well-known as effective substrates for applications in which near
field enhancements are sought. In particular, we have shown that gold nanoparticles can be
employed to carry out identification of U87 glioblastoma cells with surface enhanced Raman
spectroscopy (SERS), by targeting overexpressed aVb3 integrins via RGD peptides [1].
However, gold nanostars have been shown to lead to much higher field enhancements, owing
to their uniquely sharp protruding spikes. In particular, we have shown how they can be
employed to build sensing platforms for the direct identification of small molecule analytes by
SERS achieving femtomolar limits of detection [2]. We have also demonstrated how gold
nanostars can be tethered to rigid substrates and conjugated in situ to aptamers for targeting
and recognition of prostate cancer cells and enable the quantification of cancer cell biomarkers
at the single cell level [3]. In this talk I will also present how SERS-based quantification of
prostate specific membrane antigen (PSMA), a promising biomarker for prostate cancer
diagnosis, enables discrete patient stratification, and how gold nanostars can be uniquely
employed for the identification of influenza virus mutations at the single cell level with no
interference from protein corona.
Sense and sensitivity: SERS-based assessment of mitochondrial
bioenergetics
doi: https://doi.org/10.13052/jsame2245-4551.2018021
N. A. Brazhe1, E. I. Nikelshparg1, A. A. Semenova2, E. A. Goodilin2,3, A. A. Baizhumanov1, S. M. Novikov4, G. V. Maksimov1 and O. Sosnovtseva5
1Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russia
2Department of Nanomaterials, Faculty of Material Sciences, Moscow State University, Moscow, Russia
3Department of Inorganic Chemistry, Faculty of Chemistry, Moscow State University, Moscow, Russia
4Laboratory of Nanooptics and Plasmonics, MIPT, Dolgoprudny, Russia
5Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
Abstract: [+] | Download File [ 91KB ] | Read Article Online
Abstract: Selective and sensitive investigation of components of the electron transport chain in
functional mitochondria is important for fundamental biophysical research and for
development of new biomedical diagnostic tools. Up-to-day methods – fluorescent
microscopy, absorption spectroscopy and registration of oxygen consumption – provide only
indirect information about the redox state of electron transport chain complexes. We
suggested a novel label-free approach based on the surface-enhanced Raman spectroscopy
(SERS) to monitor conformational changes and redox state of cytochrome c in electron
transport chain of functional mitochondria.
Abstract: Compared to zero-bandgap graphene, 2D layered transition metal dichalcogenides (TMDs)
with the chemical formula MX2 (where M=group IVB-VIIB metal and X=chalcogen) have
brought new possibility for the applications in ultralow-power electronics due to the
reasonable bandgap. Currently, the carrier mobilities of TMDs at ambient conditions are a
little bit low which limit their practical applications. Many strategies, for example
synthesizing new member of 2D TMDs, revealing the transport mechanism and optimizing
the device configuration are acknowledged as the promising methods. Except metallic and
insulate property, many 2D layered materials exhibit semiconducting behavior including ntype,
p-type or ambipolar, which could be used to fabricate various electronics. Compared to
unipolar (n-type or p-type) transistors, ambipolar transistors, which can easily switch between
n-type and p-type behavior by applying an electric field, are most promising candidates since
they can effectively simplify circuit design and save the layout area in CMOS.
Study of Two Dimensional Electron Gas Formation at AlGaN/GaN
Interfaces using Kelvin Probe Force Microscopy
doi: https://doi.org/10.13052/jsame2245-4551.2018019
P. Caban1, R. Thorpe2, L. Feldman2, K. Pedersen3 and V. N. Popok1
1Institute of Electronic Materials Technology, 01-919 Warsaw, Poland
2Department of Physics & Astronomy, Rutgers, The State University of New Jersey, 08854 Piscataway, USA
3Department of Materials and Production, Aalborg University, 9220 Aalborg, Denmark
Abstract: [+] | Download File [ 336KB ] | Read Article Online
Abstract: AlGaN/GaN heterostructures are of high research and industrial interest for the production of
high electron mobility transistors utilizing the two-dimensional electron gas (2DEG) induced
at the interface due to polarization effects. Critical AlGaN thickness is an important practical
parameter which is under the study in this work.
Frictional behavior of two-dimensional materials
doi: https://doi.org/10.13052/jsame2245-4551.2018018
Suzhi Li1,2,3, Qunyang Li4, Robert W. Carpick5, Peter Gumbsch3,6 and Ju Li1,2
1Xi’an Jiaotong University, Xi’an 710049, China
2Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
3Karlsruhe Institute of Technology, Karlsruhe 76131, Germany
4Tsinghua University, Beijing 100084, China
5University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
6Fraunhofer Institute for Mechanics of Materials IWM, 79108 Freiburg, Germany
Abstract: [+] | Download File [ 527KB ] | Read Article Online
Abstract: Friction occurs when surfaces of solid bodies touch and move against each other. Energy is
thereby converted into heat that is lost. In order to reduce the friction in the metallic elements
during sliding, for example in automobiles or industrial machines, materials with a lamellar
structure are commonly used as the solid lubricants. One of the dry lubricants is graphite,
which has a three-dimensional layered structure.
Abstract: Recent advancements in atomic force microscopy facilitate atomic-resolution threedimensional
mapping of hydration layers next to macromolecules and solid surfaces. These
maps provide unprecedented information on the way water molecules organize and bind
these objects. Since the hydration structure governs the energetics of solvation and
interactions between objects immersed in solution, the new data are invaluable when trying to
resolve fundamental questions such as identification of molecular binding sites and
interaction mechanisms.
Abstract: Supramolecular elastomers (SMEs) are three-dimensional networks of polymer chains bridged
by covalent cross-links and non-covalent bonds with finite lifetimes. The reversible noncovalent
bonding is based on (i) metal-ligand coordination, (ii) electrostatic interaction, (iii)
hydrophobic association, (iv) hydrogen bonding, and (v) host-guest recognition. An advantage
of these materials compared with conventional vulcanized rubbers and thermoplastic
elastomers is their ability of rapid self-healing after damage at ambient temperature. The
mechanical response of SMEs is characterized by (i) rapid relaxation of stresses (with the
characteristic time of a few minutes), (ii) self-recovery (a monotonic reduction in plastic strain
with time after cyclic loading), and (iii) anti-fatigue (an increase in maximum stress with
number of cycles under deformation programs with intervals of recovery between cycles).
Abstract: Plasmonic nanoparticles are increasingly important tools in sensing, drug delivery and
catalysis, but an increasing number of synthetic and assembly techniques are required to design
the desired nanostructures. Synthesis of nanoparticles and the assembly of these particles into
larger combinations typically fall into two categories: top-down methods, typically using
lithographic or nanoimprinting techniques, and bottom-up synthesis, typically using
molecularly guided self-assembly of colloidal particles. There are advantages for each method,
primarily associated with the control of assembly in the top-down methods versus the
versatility and variety of colloidal particles available for the bottom-up synthesis.
Abstract: In this paper we report how block-copolymer (BCP) self-assembly of polystyrene–b–
polydimethylsiloxane (PS–PDMS) is used for in-situ nano-lithography to fabricate
hexagonally ordered nanostructures on the surface of Si.[1] This is done by forming an in-situ
etch mask on the Si surface by spin coating of the BCP in solution and subsequent solvent
annealing, and reactive ion-etching (RIE) steps. The wetting properties of the fabricated
structures are studied to reveal a multitude of possible wetting and anti-wetting
configurations, depending on the subsequent fabrication and surface coating steps.
Abstract: Here we describe the construction of double stranded (ds) concatemers composed of short (6-
10 bases) repeating tandem oligonucleotides units containing modified nucleotides. The
synthesis of incudes: self-association of the 5’-end phosphorylated half-complementary
oligonucleotides into long (hundreds of base pairs) ds nucleic acid polymers and covalent
linkage of the oligonucleotides in the strand by DNA ligase (Fig. 1B). The oligonucleotides
containing various modified nucleotides can be assembled into long (hundreds of
nanometers) ds concatamers. One of these nucleotides is amino-modified thymine in which
the amino group is linked to 5-position of the pyrimidine ring via two or six carbon atom
spacer arms.
Abstract: The dielectric constant (or electric polarizability), e
r, is a fundamental physical property of
matter which depends on chemical composition, structure and phase. It plays a crucial role in
a wide range of phenomena and disciplines, from physics and materials science to chemistry
and molecular biology. For example, in physics, it is inherently linked to charge storage and
electric transport. In biology, it modulates long-range electrostatic and van der Waals
interactions that are crucial for macromolecular assembly and interactions. Yet, probing local
dielectric properties has remained a long-standing technical challenge because the signals that
have to be detected are extremely weak and buried into non-local and geometric artefacts.
Abstract: DNA can fold into a number of secondary structures that play a role in the regulation of gene
expression [1]. It can also be harnessed as a building block in the field of DNA
nanotechnology to create both static and dynamic DNA structures of all shapes with sizes
ranging from a few to several hundreds of nanometers [2]. Owing to their phenomenal
addressability, these DNA nanostructures are attractive platforms for organizing matter at the
molecular level and provide high flexibility for positioning fluorescent molecules.
Abstract: The conductivity of DNA-templated nanowires is less than that of bulk material or other
types of nanowire, and as their structure is granular they are not usually useful as
interconnects. Single nanowire devices are rather fragile and a single break can destroy the
device completely meaning networks or bundles of nanowires are used instead. The simple
drop-casting of DNA-templated nanowires leads to the formation of networks due to the
intermolecular interactions as the liquid evaporates. However, this deposition process lacks
control and the final pattern is of low resolution. On the other hand, inkjet printing is the
controlled deposition of material at high resolution and has been routinely used to print
conductive materials. Most conductive inks contain metal nanoparticles and are formulated at
concentrations much higher than DNA-templated nanowires. Here we report the use of inkjet
printing to prepare patterns of DNA-hybrid materials for electrical characterisation.
Toward electronically-functional, self-assembling DNA nanostructures
doi: https://doi.org/10.13052/jsame2245-4551.2018008
S. Vecchioni1, M. C. Capece2, E. Toomey3, L. J. Rothschild4 and S. J. Wind5,∗
1Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
2Department of Chemistry, Stanford University, Stanford, CA 94305, USA
3Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
4NASA Ames Research Center, Biospheric Science Branch, Moffett Field, CA 94035, USA
5Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
Abstract: [+] | Download File [ 644KB ] | Read Article Online
Abstract: Recent work has demonstrated that DNA, ordinarily considered a weak conductor, can be
functionalized to carry electronic charge by site-specific incorporation of single silver ions
inside the double helix via the non-canonical pairing of mismatched cytosines through Ag+
coordination: (dC:Ag+:dC) [1,2]. Through the alteration of sequence composition and cation
availability, a variety of nanowires can be synthesized with tuneable length, ion distribution,
and uniformity. These wires are more thermostable than Watson-Crick DNA, can shield
intercalated Ag+ from aqueous solvents, and are able to form in the absence of cluster
contamination. We use computational sequence design algorithms to introduce nonlinear
geometry to these nanowires, with the goal of creating self-assembling DNA nanostructures
that may have potential for neural architectures from electrically-functional oligonucleotide
components.
Abstract: Charge transport through molecular structures is interesting both scientifically and
technologically. To date, DNA is the only type of polymer that transports significant currents
over distances of more than a few nanometers in individual molecules. Nevertheless and in
spite of large efforts to elucidate the charge transport mechanism through DNA a satisfying
characterization and mechanistic description has not been provided yet. For molecular
electronics, DNA derivatives are by far more promising than native DNA due to their improved
charge-transport properties.
Abstract: Small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) are
excellent experimental tools for obtaining structural information on macromolecules, selfassembled
structures, and nanoparticles in solution. The techniques give information on
shape, size and organization of particles and molecules of sizes up to hundreds of nanometers
with sub-nm resolution. It also provides key parameters such as mass, maximum diameter
and radius of gyration. In contrast to many other techniques, SAXS and SANS does not
require any special sample preparation or deuteration, and can be performed for almost any
solvent/buffer condition, however, D2O is usually used in the buffers for SANS as it
enhances contrast and reduce background. Furthermore, the studied assemblies or particles
may be amorphous or crystalline, may have disordered region or randomness, and may have
(smaller) variation in size and shape without spoiling the possibility of structure
determination. However, deriving detailed structural information from SAXS data requires
sophisticated analysis approaches [1,2]. There has been a large progress in analysis within the
last decades and this has led to broad field of applications of the SAXS and SANS methods.
In this lecture, the basic principles and theory will be described and some recent applications
to block copolymer micelles [3], protein-detergent complexes [4] and microgels [5] will be
presented.
New Nanoscale Polymer Systems And Their Interaction With Living Objects
doi: https://doi.org/10.13052/jsame2245-4551.2018005
M. I. Shtilman1,∗, A. N. Kuskov1, P. P. Kulikov1, A. L. Luss1, A. V. Goryachaya1, V. T. Dzhedzheya1, S. A. Gusev2, P. Henrich-Noack3, L. Gurevich4, V. P. Torchilin5, A. M. Tsatsakis6
1D.I.Mendeleyev University of Chemical Technology of Russian, Department of Biomaterials. Moscow, Russia
2Clinical Center for Physical-Chemical Medicine, Moscow, Russia
3Institute of Medical Psychology, Otto-von-Guericke University, Magdeburg, Germany
4Aalborg University, Aalborg, Denmark
5Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA 02115, USA
6University of Crete, Medical School, Division Morphology, Greece
Abstract: [+] | Download File [ 94KB ] | Read Article Online
Abstract: The synthesis methods and properties of amphiphilic polymers of N-vinylpyrrolidone,
acrylamide, acrylic acid were studied and it was shown that these systems can be used for
modification of liposomal membranes and as micelles-like aggregates [1,2].
To the date, methods have been developed for the preparation of nanoparticles based on
such polymers with immobilized poorly-soluble or insoluble in water low molecular weight,
biologically active compounds, such as indomethacin, diclofenac, amphotericin B, nystatin, 5-
fluorouracil, rifabutin, felodipine, ionol, curcumin.
Abstract: Neurological diseases such as Alzheimer’s disease and Parkinson Disease are becoming more
prevalent worldwide. Unfortunately, treatment of neurological diseases is hindered by the
inability of up to 98% of drugs with therapeutic relevance to cross the blood-brain barrier
(BBB).
The blood-brain barrier (BBB) forms a chemical, physical and immunological barrier
between the blood and the brain tissue. The BBB is formed by brain capillary endothelial
cells (BCECs), which are interconnected by tight junctions, creating a tight seal between
BCECs. Furthermore astrocytes and pericytes are situated in the near vicinity of the BCECs
and helps strengthen the barrier properties of the BCECs.
Abstract: Functional asolectin phospholipid nano-microfibers were developed using electrospinning
processing with a range of fiber diameters and morphologies, depending on the phospholipid
concentration and the solvent used [1,2]. Chloroform and dimethylformamide, isooctane,
cyclohexane and limonene were used as solvents. A critical concentration of phospholipids is
essential to favor the intermolecular association between the micelles, required for the
formation of asolectin electrospun fibers. The dielectric constant of the solvents had a strong
influence on the electrospinning jet split properties and affected the morphology of the
electrospun asolectin nano-microfibers, while co-axial electrospinning could be used to tune
their average diameter. The mechanical properties and the stability at ambient conditions of
phospholipid fibers were assessed by nanoindentation using Atomic Force Microscopy [2].
Their elastic modulus was found to be approximately 17.2 ±1 MPa, and at a cycle of piezo
expansion-retraction (loading-unloading) of a silicon tip on a fiber, a relatively high adhesion
was observed during unloading. Moreover, the efficacy of electrospun phospholipid
microfibers as antioxidants, encapsulation, and delivery matrices for bioactive compounds
and transdermal drugs, were also confirmed [3,4].
Abstract: Nanoparticles grafted with polymers are used and developed for a multitude of biomedical
and biotechnological applications (Figure 1), such as imaging contrast agents, hyperthermia
treatment drug delivery, separation and purification [1,2]. Unique functions can be achieved
for these applications by using nanoscale inorganic cores, such as nanoplasmonic metal cores
or superparamagnetic oxide cores. However, the grafted polymer shell must prevent
undesired colloidal interactions with biomolecules and cells that lead to aggregation and
clearance to enable these functions in a biological environment; it also must promote desired
specific biological interactions such as molecular and cellular targeting [1]. It is widely
recognized that one of the best ways to achieve this is through grafting of the core particle
with a dense brush of hydrophilic polymer, e.g. poly(ethylene glycol), which prevents protein
and other biomolecules from binding to the particle and provides a scaffold for controlled
functionalization with biofunctional ligands.
Immobilization of recombinant β-glucosidase on magnetic nanoparticles and its
potential in production of ginsenoside F2 and Compound K
doi: https://doi.org/10.13052/jsame2245-4551.2018001
Bianling Zhang1, Zhengjun Fang1,2, Wanmin Liu1,2, Qiang Tao1,2 and Ru Zhang1,2
1College of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China
2Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
Abstract: [+] | Download File [ 95KB ] | Read Article Online
Abstract: In the present study, BbBgl gene was cloned and expressed in E. coli BL21. The β-
glucosidase was purified by Ni-NTA magnetic beads to obtain an enzyme with specific
activity of 37 U/mg protein using pNP-Glc as substrate. The enzyme activity was optimized
at pH 5.0, 35°C, 2 or 6 U/ml. The recombinant β-glucosidase was immobilized to magnetic
Fe3O4 nanoparticles. Furthermore, the optimal conditions for the immobilization and some
characteristics of immobilized enzyme were studied. The optimal immobilization conditions
observed were enzyme 0.15 mg (1 mg/mL, 0.15 mL), magnetic Fe3O4 nanoparticles 3 mg, pH
5.0, immobilization time 4 h. The results showed that the optimal reaction temperature of
immobilized enzyme kept in a high activity from 35°C to 40°C. Thermal stability of the
immobilized enzyme also had an improvement, the residual activity retained 62% and 57%
after 180 h at 35°C and 40°C, respectively, while free enzymes only showed 55% and 51%
remnant activity at the same condition.
