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Abstract

Current vehicles used to deliver antisense oligonucleotides (ASOs) cannot distinguish between bacterial and mammalian cells, greatly hindering the preclinical or clinical treatment of bacterial infections, especially those caused by antibiotic-resistant bacteria. Herein, we leverage the bacteria-specific ATP-binding cassette (ABC) sugar transporters to selectively internalize ASOs by hitchhiking them on α (1-4)-glucosidically linked glucose polymers. Compared with their cell-penetrating peptide counterparts, which are non-specifically engulfed by mammalian and bacterial cells, the presented therapeutics consisting of glucose polymer and antisense peptide nucleic acid-modified nanoparticles are selectively internalized into the human-derived multidrug-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus, and they display a much higher uptake rate (i.e., 51.6%). The developed strategy allows specific and efficient killing of nearly 100% of the antibiotic-resistant bacteria. We also show its significant curative efficacy against bacterial keratitis and endophthalmitis. This strategy will expand the focus of antisense technology to include bacterial cells other than mammalian cells.

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Abstract

Efficient energy transport over long distances is essential for optoelectronic and light-harvesting devices. Although self-assembled nanofibers of organic molecules have been shown to exhibit long exciton diffusion lengths, alignment of these nanofibers into films with large, organized domains with similar properties remains a challenge. Here, we show how the functionalization of C 3-symmetric carbonyl-bridged triarylamine trisamide (CBT) oligodimethylsiloxane (oDMS) sidechains with discrete length leads to fully covered surfaces with aligned domains up to 125 × 70 μm2 in which long-range exciton transport takes place. The nanoscale morphology within the domains consists of highly ordered nanofibers with discrete intercolumnar spacings within a soft amorphous oDMS matrix. The oDMS prevents bundling of the CBT fibers, reducing the number of defects within the CBT columns. As a result, the columns have a high degree of coherence, leading to exciton diffusion lengths of a few hundred nanometers with exciton diffusivities (∼0.05 cm2 s−1) that are comparable to those of a crystalline tetracene. These findings represent the next step towards fully covered surfaces of highly aligned nanofibers through functionalization with oDMS.

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Abstract

Innovation in ionotronics field has significantly accelerated the development of ultra-flexible devices and machines. However, it is still challenging to develop efficient ionotronic-based fibers with necessary stretchability, resilience, and conductivity due to inherent conflict in producing spinning dopes with both high polymer and ion concentrations and low viscosities. Inspired by the liquid crystalline spinning of animal silk, this study circumvents the inherent tradeoff in other spinning methods by dry spinning a nematic silk microfibril dope solution. The liquid crystalline texture allows the spinning dope to flow through the spinneret and form free-standing fibers under minimal external forces. The resultant silk sourced ionotronic fibers (SSIFs) are highly stretchable, tough, resilient, and fatigue-resistant. These mechanical advantages ensure a rapid and recoverable electromechanical response of SSIFs to kinematic deformations. Further, the incorporation of SSIFs into core–shell triboelectric nanogenerator fibers provides outstanding stable and sensitive triboelectric response to precisely and sensitively perceive small pressures. Moreover, by implementing a combination of machine learning and Internet of Things techniques, the SSIFs could sort objects made of different materials. With these structural, processing, performance, and functional merits, the SSIFs prepared herein are expected to be applied in human–machine interfaces.

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Abstract

Raman spectroscopy is an analytical method based on light-matter interactions that can interrogate the vibrational modes of matter and provide representative molecular fingerprints. Mediated by its label-free, non-invasive nature and high molecular specificity, Raman-based techniques have become ubiquitous tools for in situ characterisation of materials. This review comprehensively describes the theoretical and practical background of Raman spectroscopy and its advanced variants. We highlight the numerous facets of material characterisation that Raman scattering can reveal, including biomolecular identification, solid-to-solid phase transitions and spatial mapping of biomolecular species in bioactive materials. The review illustrates the potential of these techniques in the context of active biomedical material design and development by highlighting representative studies from the literature. These studies cover the use of Raman spectroscopy for the characterisation of both natural and synthetic biomaterials, including engineered tissue constructs, biopolymer systems, ceramics and nanoparticle formulations, among others. To increase the accessibility and adoption of these techniques, the present review also provides the reader with practical recommendations on the integration of Raman techniques into the experimental laboratory toolbox. Finally, we provide perspectives on how recent developments in plasmon- and coherently-enhanced Raman spectroscopy can propel Raman from underutilised to critical for biomaterial development.

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Abstract

Many artificial miniature robotic collectives have been developed by emulating collective biological behaviors to overcome the inherent limitations of inadequate individual capabilities. However, the basic building blocks of the reported collectives are mainly in the solid state, where the morphological boundaries of internal individuals are clear and cannot genuinely merge. Miniature robotic collectives based on liquid units still need to be explored; such on-demand mergeable swarm systems are advantageous for adapting to the changing external environment. Here, we present a strategy to achieve a coalescent collective system that exploits the ferrofluid droplets' splitting and coalescence properties to trigger the formation of horizontal multimodal and vertical gravity-resistant collectives and unveil pattern-enabled robotic functionalities. When subjected to a time-varying magnetic field, the droplet swarm exhibits a variety of morphologies ranging from horizontal collectives, including vortex-like, chain-like, and crystal-like patterns to vertical layer-upon-layer patterns. Using experiments and simulations, we show the formation and transformation of different morphological collectives and demonstrate their robust environmental adaptability. Potential applications of the multimodal droplet collectives are presented, including exploring an unknown environment, targeted object delivery, and fluid flow filtration in a lab-on-a-chip. This work may facilitate the design of microrobotic swarm systems and expand the range of materials for miniature robots.

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Abstract

Integrating photovoltaic devices onto the surface of carbon fibre-reinforced polymer substrates should create materials with high mechanical strength that are also able to generate electrical power. Such devices are anticipated to find ready applications as structural, energy-harvesting systems in both the automotive and aeronautical sectors. Here, we demonstrate the fabrication of triple-cation perovskite n-i-p solar cells onto the surface of planarised carbon fibre-reinforced polymer substrates, with devices utilising a transparent top ITO contact. These devices also contain a “wrinkled” SiO2 interlayer placed between the device and substrate which alleviates thermally-induced cracking of the bottom ITO layer. Our devices were found to have a stabilised power conversion efficiency of 14.5% and a specific power (power per weight) of 21.4 W g−1 (without encapsulation), making them highly suitable for mobile power applications.

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Abstract

Constructed through relatively weak noncovalent forces, the stability of organic supramolecular materials has shown to be a challenge. Herein, designing of linear conjugated polymer is proposed through creating chain polymer connected via bridging covalent bonds in one direction and retaining π−stacked aromatic columns in its orthogonal direction. Specifically, three analogues of linear conjugated polymers through tuning aromatic core and its covalently linked moiety (bridging group) within the building block monomer were prepared. Cooperatively supported by strong π-π stacking interactions from the extended aromatic core of perylene and favorable dipole-dipole interactions from bridging group, the as-expected high crystallinity, wide light absorption and increased stability was successfully achieved for Oxamide-PDI through ordered molecular arrangement, and presented a remarkable full-spectrum oxygen evolution rate of 5110.25 μmol g−1 h−1 without any cocatalyst. Notably, experimental and theoretical studies revealed that large internal dipole moments within Oxamide-PDI DFT together with its ordered crystalline structure enabled a robust built-in electric field for efficient charge carrier migration and separation. Moreover, DFT calculations also revealed oxidative sites located at carbon atoms next to imide bonds and inner bay positions based on proved spatially separated photogenerated electrons and holes, thus resulting in highly efficient water photolysis into oxygen.

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Abstract

Reducible metal oxide nanozymes (rNZs) have been a subject of intense recent interest due to their catalytic nature, ease of synthesis, and complex surface character. Such materials contain surface sites which facilitate enzyme-mimetic reactions via substrate coordination and redox cycling. Further, these surface reactive sites have been shown to be highly sensitive to stresses within the nanomaterial lattice, the physicochemical environment, and to processing conditions occurring as part of their syntheses. When administered in vivo, a complex protein corona binds to the surface, redefining its biological identity and subsequent interactions within the biological system. Catalytic activities of rNZs each deliver a differing impact on protein corona formation, its composition, and in turn, their recognition, and internalization by host cells. Improving our understanding of the precise principles that dominate rNZ surface-biomolecule adsorption raises the question of whether designer rNZs can be engineered to prevent corona formation, or indeed to produce “custom” protein coronas applied either in vitro, and pre-administration, or formed immediately upon their exposure to body fluids. Here, we consider fundamental surface chemistry processes and their implications in rNZ material performance. In particular, we discuss material structures which inform component adsorption from the application environment, including substrates for enzyme-mimetic reactions.

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Abstract

Population growth, urbanization, and decarbonization efforts are collectively straining the supply of limited resources that are necessary to produce batteries, electronics, chemicals, fertilizers, and other important products. Securing the supply chains of these critical resources via the development of separation technologies for their recovery represents a major global challenge to ensure stability and security. Surface water, groundwater, and wastewater are emerging as potential new sources to bolster these supply chains. Recently, a variety of material-based technologies have been developed and employed for separations and resource recovery in water. Judicious selection and design of these materials to tune their properties for targeting specific solutes is central to realizing the potential of water as a source for critical resources. Here, we review the materials that have been developed for membranes, sorbents, catalysts, electrodes, and interfacial solar steam generators (ISSGs) that demonstrate promise for applications in critical resource recovery. In addition, we offer a critical perspective on the grand challenges and key research directions that need to be addressed to improve their practical viability.

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Energy Environ. Sci., 2023, Accepted Manuscript
DOI: 10.1039/D3EE00501A, PaperYongqiang Yang, Shan Guo, Yicai Pan, Bingan Lu, Shuquan Liang, Jiang Zhou
Material with layered structure has been widely adopted as ion(s)−(de)intercalated type cathode for zinc ion battery but suffered from limited operating voltage of restricted redox couple. While I−/I2 transition with...
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Energy Environ. Sci., 2023, Accepted Manuscript
DOI: 10.1039/D3EE00539A, PaperHuiyuan Wu, Jian Wang, Wencong He, Chuncai Shan, Shaoke Fu, Gui Li, Qionghua Zhao, Wenlin Liu, Chenguo Hu
Charge density is a critical parameter for evaluating the output performance of triboelectric nanogenerator (TENG). Charge excitation (CE) strategy is currently a prefered method to boosting output charge density. However,...
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Machine-learning-enabled discovery of extreme chemistry

Abstract not available

• Speaker: Prof. Reinhard Maurer, University of Warwick
• Monday 17 April 2023, 16:00-17:00
• Venue: Dept of Chemistry, Wolfson Lecture Theatre .
• Series: Chemistry Departmental-wide lectures; organiser: Chloe Barker.

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The current state of thermal management of neuromorphic computing technology is described and the challenges and opportunities of energy efficient implementation of neuromorphic devices are addressed. The fundamental features of the brain's thermal regulation and their further physical implementation are discussed. It is believed that the underlined importance of thermal management of neuromorphic computing technology will guide researchers in this field.

Abstract

Machine learning has experienced unprecedented growth in recent years, often referred to as an “artificial intelligence revolution.” Biological systems inspire the fundamental approach for this new computing paradigm: using neural networks to classify large amounts of data into sorting categories. Current machine-learning schemes implement simulated neurons and synapses on standard computers based on a von Neumann architecture. This approach is inefficient in energy consumption, and thermal management, motivating the search for hardware-based systems that imitate the brain. Here, the present state of thermal management of neuromorphic computing technology and the challenges and opportunities of the energy-efficient implementation of neuromorphic devices are considered. The main features of brain-inspired computing and quantum materials for implementing neuromorphic devices are briefly described, the brain criticality and resistive switching-based neuromorphic devices are discussed, the energy and electrical considerations for spiking-based computation are presented, the fundamental features of the brain's thermal regulation are addressed, the physical mechanisms for thermal management and thermoelectric control of materials and neuromorphic devices are analyzed, and challenges and new avenues for implementing energy-efficient computing are described.

TBC

TBC

• Speaker: Daniela Sclavo
• Tuesday 06 June 2023, 13:15-14:00
• Venue: 1 Newnham Terrace, Darwin College.
• Series: Darwin College Humanities and Social Sciences Seminars; organiser: Dr Stefanie Ullmann.

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Abstract

In lithium metal batteries (LMBs), the compatibility of Li anode and conventional lithium hexafluorophosphate-(LiPF6) carbonate electrolyte is poor owing to the severe parasitic reactions. Herein, to resolve this issue, a delicately designed additive of potassium perfluoropinacolatoborate (KFPB) is unprecedentedly synthesized. On the one hand, KFPB additive can regulate the solvation structure of the carbonate electrolyte, promoting the formation of Li+-FPB− and K+-PF6 − ion-pairs with lower lowest unoccupied molecular orbital (LUMO) energy levels; On the other hand, FPB− anion possesses strong adsorption ability on Li anode.Thus, anions can preferentially adsorb and decompose on the Li anode surface to form a conductive and robust solid electrolyte interphase (SEI) layer. Only a trace amount of KFPB additive (0.03 M) in the carbonate electrolyte, Li dendrites growth can be totally suppressed and Li||Cu and Li||Li half cells exhibit excellent Li plating/stripping stability upon cycling. Encouragingly, KFPB assisted carbonate electrolyte enables high areal capacity LiCoO2||Li, LiNi0.8Co0.1Mn0.1O2 (NCM811)||Li, and LiNi0.8Co0.05Al0.15O2 (NCA)||Li LMBs with superior cycling stability, showing its excellent universality. This work reveals the importance of designing novel additives to regulate the solvation structure of carbonate electrolytes in improving its interface compatibility with the Li anode.

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Abstract

Transport layers are of outmost importance for thin film solar cells, determining not only their efficiency but also their stability. To bring one of these thin film technologies towards commercialization, many factors besides efficiency and stability become important, including the ease of deposition in a scalable manner and the cost of the different material's layers. Herein, highly efficient organic solar cells (OSCs), in the inverted structure (n-i-p), are demonstrated by using as electron transport layer (ETL) tin oxide (SnO2) deposited by atomic layer deposition (ALD). ALD is an industrial grade technique which can be applied both at the wafer level but also in a roll-to-roll configuration. A champion efficiency of 17.26% and a record FF of 79% is shown by PM6:L8-BO OSCs when using ALD-SnO2 as ETL. These devices outperform not only solar cells with SnO2 nanoparticles casted from solution (PCE 16.03%, FF 74%) but also those utilizing the more common sol-gel ZnO (PCE 16.84%, FF 77%). The outstanding results are attributed to a reduced charge carrier recombination at the interface between the ALD-SnO2 film and the active layer. Furthermore, a higher stability under illumination is demonstrated for the devices with ALD-SnO2 in comparison with those utilizing ZnO.

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Abstract

Taking advantage of effective intracellular delivery mechanisms of both cationizable lipids and polymers, highly potent double pH-responsive nucleic acid carriers were generated by combining at least two lipo amino fatty acids (LAFs) as hydrophobic cationizable motifs with hydrophilic cationizable aminoethylene units into novel sequence-defined molecules. The pH-dependent tunable polarity of the LAF was successfully implemented by inserting a central tertiary amine, which disrupts the hydrophobic character once protonated, resulting in pH-dependent structural and physical changes. This “molecular chameleon character” turned out to be advantageous for dynamic nucleic acid delivery via lipopolyplexes. By screening of different topologies (blocks, bundles, T-shapes, U-shapes), LAF types, and LAF/aminoethylene ratios, highly potent pDNA, mRNA, and siRNA carriers were identified, which were up to several hundred-fold more efficient than previous carrier generations and characterized by very fast transfection kinetics. mRNA lipopolyplexes maintained high transfection activity in cell culture even in the presence of ≥90% serum at an ultra-low mRNA dose of 3 picogram (∼2 nanoparticles/cell), and thus are comparable in potency to viral nanoparticles. Importantly, they showed great in vivo performance with high expression levels especially in spleen, tumor, lungs, and liver upon intravenous administration of 1–3 μg luciferase-encoding mRNA in mice.

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Abstract

Advances in emerging technologies for wireless collection and the timely analysis of various information captured by wearable devices are of growing interest. Herein, we propose a crosslinked ionic hydrogel prepared by a facile photocuring process, that allows wearable devices to be further incorporated into two wireless integrated systems for pressure monitoring applications. The device exhibits a simplified structure by effectively sharing functional layers, rather than conventional two separate combinations, offering the salient performance of iontronic sensing and electrochromic properties to simultaneously quantify and visualize pressure. The developed smart patch system was demonstrated to monitor physiological signals in real-time using the user interface of remote portable equipment with Bluetooth protocol and on-site electrochromic displays. Moreover, a passive wireless system based on the magnetic coupling effect was designed, which could operate free from the battery and simultaneously acquire multiple pressure information. It is envisioned that the strategies would hold enormous potential for flexible electronics, versatile sensing platforms and wireless on-body networks.

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Title to be confirmed

Abstract not available

• Speaker: Dr Hamdi Joudeh
• Wednesday 03 May 2023, 14:00-15:00
• Venue: MR5, CMS Pavilion A.
• Series: Information Theory Seminar; organiser: Dr Varun Jog.

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Title to be confirmed

Abstract not available

Note unusual day of the week

• Speaker: Dr Anelia Somekh-Baruch, Bar-Ilan University
• Monday 22 May 2023, 14:00-15:00
• Venue: MR5, CMS Pavilion A.
• Series: Information Theory Seminar; organiser: Dr Varun Jog.

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