425 results match your criteria: "The MacDiarmid Institute[Affiliation]"
Eur Biophys J
July 2023
Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
Within the complex milieu of a cell, which comprises a large number of different biomolecules, interactions are critical for function. In this post-reductionist era of biochemical research, the 'holy grail' for studying biomolecular interactions is to be able to characterize them in native environments. While there are a limited number of in situ experimental techniques currently available, there is a continuing need to develop new methods for the analysis of biomolecular complexes that can cope with the additional complexities introduced by native-like solutions.
View Article and Find Full Text PDFEnviron Sci Technol
January 2023
Centre for Green Chemical Science, University of Auckland, Auckland 1010, New Zealand.
Perfluorosulfonic acids (PFSAs) are a recalcitrant subclass of per- and polyfluoroalkyl substances (PFASs) linked to numerous negative health effects in humans. Scalable technologies that effectively destroy PFSAs will greatly reduce the future health and ecological impact of these "forever chemicals". Herein, we show that several PFSAs undergo facile mechanochemical destruction (MCD) in the presence of quartz sand (SiO).
View Article and Find Full Text PDFPharmaceutics
December 2022
Department of Earth, Environmental & Physical Sciences, University of Siena, Pian Mantellini 44, 53100 Siena, Italy.
In this work, giant unilamellar vesicles (GUVs) were synthesized by blending the natural phospholipid 1-palmitoyl-2-oleoyl--glycero-3-phosphocholine (POPC) with a photoswitchable amphiphile () that undergoes photoisomerization upon irradiation with UV-A ( to ) and blue ( to ) light. The mixed vesicles showed marked changes in behavior in response to UV light, including changes in morphology and the opening of pores. The fine control of membrane permeability with consequent cargo release could be attained by modulating either the UV irradiation intensity or the membrane composition.
View Article and Find Full Text PDFBiosensors (Basel)
December 2022
Polymer Biointerface Centre, School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand.
Biofouling on surfaces, caused by the assimilation of proteins, peptides, lipids and microorganisms, leads to contamination, deterioration and failure of biomedical devices and causes implants rejection. To address these issues, various antifouling strategies have been extensively studied, including polyethylene glycol-based polymer brushes. Conducting polymers-based biointerfaces have emerged as advanced surfaces for interfacing biological tissues and organs with electronics.
View Article and Find Full Text PDFBioconjug Chem
January 2023
School of Chemical Sciences, The University of Auckland, Science Centre, Building 302, 23 Symonds Street, Auckland 1142, New Zealand.
The para-fluoro-thiol reaction (PFTR) is a modern name for the much older concept of a nucleophilic aromatic substitution reaction in which the para-position fluorine of a perfluorinated benzene moiety is substituted by a thiol. As a rapid and mild reaction, the PFTR is a useful technique for the post-synthetic modification of macromolecules like peptides on the solid phase. This reaction is of great potential since it allows for peptide chemists to access the vast catalogue of commercially available thiols with diverse structures to conjugate to peptides, which may impart favorable biological activity, particularly in antimicrobial sequences.
View Article and Find Full Text PDFLuminescence
January 2023
School of Chemical and Physical Sciences, The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Dodd-Walls Centre for Photonic and Quantum Technologies, Victoria University of Wellington, Wellington, New Zealand.
The lighting industry currently accounts for a significant proportion of all energy demand. Luminescent white lighting is often impure, inefficient, expensive, and detrimentally emits as a point source, meaning the light is emitted from a focused point. A luminescent light diffuser offers the potential to create a spatially broad lighting fixture.
View Article and Find Full Text PDFSci Rep
November 2022
Toha Foundry, Auckland, 1025, New Zealand.
Molecular dynamics simulations have shown that after initial surface melting, nanowires can melt via two mechanisms: an interface front moves towards the wire centre; the growth of instabilities at the interface can cause the solid to pinch-off and breakup. By perturbing a capillary fluctuation model describing the interface kinetics, we show when each mechanism is preferred and compare the results to molecular dynamics simulation. A Plateau-Rayleigh-type of instability is found and suggests longer nanowires will melt via an instability mechanism, whereas in shorter nanowires the melting front will move closer to the centre before the solid pinch-off can initiate.
View Article and Find Full Text PDFJ Phys Chem B
November 2022
Faculty of Chemistry, University of Gdańsk, Fahrenheit Union of Universities in Gdańsk, Wita Stwosza 63, 80-308Gdańsk, Poland.
By analyzing the Kubo-cluster-cumulant expansion of the potential of mean force of polypeptide chains corresponding to backbone-local interactions averaged over the rotation of the peptide groups about the C···C virtual bonds, we identified two important kinds of "along-chain" correlations that pertain to extended chain segments bordered by turns (usually the β-strands) and to the folded spring-like segments (usually α-helices), respectively, and are expressed as multitorsional potentials. These terms affect the positioning of structural elements with respect to each other and, consequently, contribute to determining their packing. Additionally, for extended chain segments, the correlation terms contribute to propagating the conformational change at one end to the other end, which is characteristic of allosteric interactions.
View Article and Find Full Text PDFRSC Adv
October 2022
Department of Science Education and Application, National Taichung University of Education Taichung 403 Taiwan Republic of China.
In this paper, silver niobate (AgNbO) material was synthesized by a solid-state reaction. AgNbO was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET) measurement. The photocatalytic activity of AgNbO was investigated in degradation of sulfamethoxazole (SMX) under visible light, which is a widely used antibiotic with significant threats towards health and aquatic organisms.
View Article and Find Full Text PDFNanomaterials (Basel)
October 2022
Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
Herein, the UV light photocatalytic activity of an AuNC-AlSrTiO-rGO nanocomposite comprising 1 wt% rGO, 0.05 wt% Au(PPh)Cl (AuNC), and AlSrTiO evaluated for H production. The synthesis of AuNC-AlSrTiO-rGO nanocomposite followed two distinct routes: (1) AuNC was first mixed with AlSrTiO followed by the addition of rGO (AuNC-AlSrTiO:rGO) and (2) AuNC was first mixed with rGO followed by the addition of AlSrTiO (AuNC-rGO:AlSrTiO).
View Article and Find Full Text PDFBioengineering (Basel)
October 2022
Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand.
Nanomaterial-based aptasensors are useful devices capable of detecting small biological species. Determining suitable signal processing methods can improve the identification and quantification of target analytes detected by the biosensor and consequently improve the biosensor's performance. In this work, we propose a data augmentation method to overcome the insufficient amount of available original data and long short-term memory (LSTM) to automatically predict the analyte concentration from part of a signal registered by three electrochemical aptasensors, with differences in bioreceptors, analytes, and the signals' lengths for specific concentrations.
View Article and Find Full Text PDFPolymers (Basel)
September 2022
School of Chemical Sciences, University of Auckland, Private Bag, Auckland 92019, New Zealand.
This review surveys and summarizes the materials and methods used to make liquid filtration membranes. Examples of each method including phase inversion, electrospinning, interfacial polymerization, thin film composites, stretching, lithography and templating techniques, are given and the pros and cons of each method are discussed. Trends of recent literature are also discussed and their potential direction is deliberated.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2022
Department of Electrical and Computer Engineering, University of Canterbury, Christchurch 8041, New Zealand.
Perovskite materials offer high-efficiency low-cost solar cells and applications versatility. We report on cesium-based hybrid perovskite solar cells with wavelength-selective properties ranging from 500 nm (UV-VIS) to 800 nm (IR). The band gap tuning was achieved through composition changes of mainly lead(II) iodide PbI and lead(II) bromide PbBr The optical spectra of the developed materials were studied, including the photoluminescence (PL), optical transparency, X-ray diffraction and external quantum efficiency for samples prepared under different compositions.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2022
Flinders Institute for Nanoscale Science and Technology, Flinders University, Adelaide, SA 5042, Australia.
Radio frequency (RF) magnetron sputtering allows the fabrication of TiO films with high purity, reliable control of film thickness, and uniform morphology. In the present study, the change in surface roughness upon heating two different thicknesses of RF sputter-deposited TiO films was investigated. As a measure of the process of the change in surface morphology, chemically -synthesised phosphine-protected Au clusters covered by a photodeposited CrO layer were used as a probe.
View Article and Find Full Text PDFNanoscale Adv
July 2022
Institute for Materials Science, Chair for Multicomponent Materials, Faculty of Engineering, Kiel University Kaiserstraße 2 D-24143 Kiel Germany
Random networks of nanoparticle-based memristive switches enable pathways for emulating highly complex and self-organized synaptic connectivity together with their emergent functional behavior known from biological neuronal networks. They therefore embody a distinct class of neuromorphic hardware architectures and provide an alternative to highly regular arrays of memristors. Especially, networks of memristive nanoparticles (NPs) poised at the percolation threshold are promising due to their capabilities of showing brain-like activity such as critical dynamics or long-range temporal correlation (LRTC), which are closely connected to the computational capabilities in biological neuronal networks.
View Article and Find Full Text PDFActa Biomater
October 2022
Leather and Shoe Research Association of New Zealand, Palmerston North, New Zealand.
Chemically crosslinked acellular bovine pericardium (ABP) has been widely used in clinical practice as bioprostheses. To ensure its consistency and durability, crosslinkers are used in excess, with stability guided by indicators including the hydrothermal denaturation temperature, the enzymatic resistance and the degree of crosslinking. Yet, understanding of the intermolecular structure in collagen fibrils which imparts the intrinsic stability of the ABPs is lacking, and the discrepancies in the stability criteria in varied conditions are poorly explained.
View Article and Find Full Text PDFFood Chem
January 2023
Department of Food Science and Microbiology, Auckland University of Technology, New Zealand. Electronic address:
Avocado seeds account for 13% of the waste from industrial production of cold-pressed avocado oil (CPAO). Therefore, the aim of this study was to valorise avocado seeds by converting it into an extruded snack product using a friction cooker and comparing their textural and physical characteristics to extruded brown rice and malted barley ready to eat (RTE) snacks. Concentration of toxins; amygdalin and persin were compared in extruded avocado seed and fresh avocado seeds.
View Article and Find Full Text PDFNat Commun
August 2022
Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA.
Two-dimensional (2D) Dirac states with linear dispersion have been observed in graphene and on the surface of topological insulators. 2D Dirac states discovered so far are exclusively pinned at high-symmetry points of the Brillouin zone, for example, surface Dirac states at [Formula: see text] in topological insulators BiSe(Te) and Dirac cones at K and [Formula: see text] points in graphene. The low-energy dispersion of those Dirac states are isotropic due to the constraints of crystal symmetries.
View Article and Find Full Text PDFRSC Adv
July 2022
School of Chemical Sciences, The University of Auckland Auckland 1010 New Zealand
This work presents a novel filter paper-based method using surface-enhanced Raman spectroscopy (SERS), for detecting polystyrene nanoplastics (PSNPs). The SERS system used a simple mixture of spherical Au nanoparticles (AuNPs) and 20 nm nanoplastics deposited onto a filter paper which offered a detection limit of 10 μg mL with a sample volume of 50 μL, and in a rare case 5.0 μg mL (with four aliquits of 50 μL).
View Article and Find Full Text PDFPolymers (Basel)
July 2022
School of Chemical Sciences, University of Auckland, Private Bag, Auckland 92019, New Zealand.
The conformation of a fluorescent polymer, in the solid state or in solution, plays a critical role in the polymer's fluorescent properties. Thus, grafted side chains on a fluorescent polymer can directly influence its optical properties. In this study, the effect of grafted polymeric side chains on the photoluminescent properties of poly(para-phenylene vinylene) (PPV) and poly(para-phenylene ethynylene) (PPE) were investigated.
View Article and Find Full Text PDFNeural Netw
October 2022
The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Physical and Chemical Sciences, Te Kura Matū, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand. Electronic address:
Networks of nanowires are currently being explored for a range of applications in brain-like (or neuromorphic) computing, and especially in reservoir computing (RC). Fabrication of real-world computing devices requires that the nanowires are deposited sequentially, leading to stacking of the wires on top of each other. However, most simulations of computational tasks using these systems treat the nanowires as 1D objects lying in a perfectly 2D plane - the effect of stacking on RC performance has not yet been established.
View Article and Find Full Text PDFFront Cell Dev Biol
July 2022
Department of Chemical and Materials Engineering, Faculty of Engineering, The University of Auckland, Auckland, New Zealand.
Variations in mechanical properties of the extracellular matrix occurs in various processes, such as tissue fibrosis. The impact of changes in tissue stiffness on cell behaviour are studied using various types of biomaterials and methods. Stiffness patterning of hydrogel scaffolds, through the use of stiffness gradients for instance, allows the modelling and studying of cellular responses to fibrotic mechanisms.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2022
The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand.
DNA aptamers have emerged as promising probes for challenging analytes that cannot be easily detected by conventional probes, including small-molecule targets. Among the different signal transduction approaches, gold nanoparticle (AuNP) aggregation assays have been widely used to generate a colorimetric response from aptamer-target interactions. This sensor design relies on the competition between the aptamer adsorbing to the AuNP surface versus interacting with the target, whereby target binding reduces the number of adsorbed aptamers that destabilizes AuNPs toward salt-induced aggregation, thereby inducing a color change.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2022
Polymer Biointerface Centre, School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand.
Electrochemical techniques offer great opportunities for the capture of chemical and biological entities from complex mixtures and their subsequent release into clean buffers for analysis. Such methods are clean, robust, rapid, and compatible with a wide range of biological fluids. Here, we designed an electrochemically addressable system, based on a conducting terpolymer [P(EDOTEDOTSAcEDOTEG)] coated onto a carbon cloth substrate, to selectively capture and release biological entities using a simple electrochemical redox process.
View Article and Find Full Text PDFChemistry
October 2022
Research School of Chemistry, Australian National University, Canberra, 2600 ACT, Australia.
As hydrogen bonded frameworks are held together by relatively weak interactions, they often form several different frameworks under slightly different synthesis conditions and respond dynamically to stimuli such as heat and vacuum. However, these dynamic restructuring processes are often poorly understood. In this work, three isoreticular hydrogen bonded organic frameworks assembled through charge-assisted amidinium⋅⋅⋅carboxylate hydrogen bonds (1 , 1 and 1 ) are studied.
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