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Corrosion-induced degradation in marine steel structures is highly dependent on the surrounding environmental conditions and sea water compositions that varies significantly around global sea water bodies. This research investigates the corrosion behaviour of ship-grade steels exposed under different sea water compositions and environmental conditions typical of the Arabian Sea. More, environmental conditions spanning those anticipated for the shipping structures operating in the highly saline and warmest regions in the Arabian Sea have been simulated in laboratory-based experiments by using heated and aerated artificial sea water. Following their exposures, the corrosion performance of coupons has been investigated using the standard weight loss and a new dimensional metrology-based approach. Besides, the corrosion products formed on the steel surfaces have been characterised using various analytical techniques. Considerably higher corrosion losses and maximum corrosion depths were observed in the nutrient-rich polluted sea waters than those recorded in the natural sea waters, as well as in the simulated artificial sea water conditions.

Here, we report the growth of bioelectret crystal films of L-leucine on conductive substrates and detail the first quantitative measurements of the direct piezoelectric effect in this proteinogenic amino acid. Through extensive electromechanical characterisation, we demonstrate that L-leucine is a promising candidate material for use in non-toxic, biocompatible and biodegradable energy harvesting and sensing devices. The data presented here is among, if not the, largest set of quasi-static, longitudinal piezoelectric measurements on crystalline films of a proteinogenic amino acid to date. We substantiate these measurements using a combination of density functional theory calculations and optical microscopy. Our data provides a further example of the enormous unexploited potential of amino acids and similar biological materials in flexible energy harvesting applications. Their combination of sizeable piezoelectric strain constants and extremely low elastic and dielectric constants makes them ideal as biocompatible replacements for toxic, expensive inorganic piezoelectric materials.

peer-reviewed Molecular stacking modes, generally classified as H-, J-, and X-aggregation, play a key role in determining the optoelectronic properties of organic crystals. However, the control of stacking transformation of a specific molecule is an unmet challenge, and a priori prediction of the performance in different stacking modes is extraordinarily difficult to achieve. In particular, the existence of hybrid stacking modes and their combined effect on physicochemical properties of molecular crystals are not fully understood. Herein, unexpected stacking transformation from H- to J- and X-aggregation is observed in the crystal structure of a small heterocyclic molecule, 4,4'-bipyridine (4,4'-Bpy), upon coassembly with N-acetyl-l-alanine (AcA), a nonaromatic amino acid derivative. This structural transformation into hybrid stacking mode improves physicochemical properties of the cocrystals, including a large red-shifted emission, enhanced supramolecular chirality, improved thermal stability, and higher mechanical properties. While a single crystal of 4,4'-Bpy shows good optical waveguiding and piezoelectric properties due to the uniform elongated needles and low symmetry of crystal packing, the significantly lower band gap and resistance of the cocrystal indicate improved conductivity. This study not only demonstrates cocrystallization-induced packing transformation between H-, J-, and X-aggregations in the solid state, leading to tunable mechanical and optoelectronic properties, but also will inspire future molecular design of organic functional materials by the coassembly strategy. ACCEPTED peer-reviewed

Broadband mid-infrared (B-MIR) thermography using fibre optic waveguides can be critical in real-time imaging in harsh environments such as additive manufacturing, personalised medical diagnosis and therapy. We investigate the polarisation effect on thermal measurements through poly-crystalline fibre bundle employing a simple broadband cross-polarisation configuration experimental set-up. Silver halide poly-crystalline fibres AgCl1−xBrx (0 ≤ x≤1) (AgClBr-PolyC) have very wide transmission bandwidth spanning over the spectral range from 1 µm up to 31 µm FWHM. Moreover, they are non-toxic, non-hygroscopic, with relatively good flexibility, which make them very adequate for spectroscopic and thermal measurements in medical and clinical fields. In this study, we used a fibre bundle composed of seven single AgClBr-PolyC fibres, each with a core diameter of about 300 µm, inserted between two broadband MIR polarisers.A silicon carbide filament source was placed at the entrance of the fibre bundle, while a FLIR thermal camera with a close-up lens was employed to measure the spatial temperature distribution over the fibre-bundle end. Indeed, polarisation dependence of temperature measurements has been clearly observed in which the orientation of temperature extrema (minima and maxima)vary from one fibre to another within the bundle. Moreover, these observations have enabled the classification of AgClBr-PolyC fibres following their polarisation sensitivities by which some fibres are relatively highly sensitive to polarisation with polarisation temperature difference (PTD) that can reach 22.1 ± 2.8 °C, whereas some others show very low PTD values down to 3.1 ± 2.8 °C. Many applications can readily be found based on the advantages of both extreme cases. © 2020, The Author(s). SM, AM, CS, JB and SAMT acknowledge European Commission Erasmus International Credit Mobility 2015–2020 between Ural Federal University named after the frst President of Russia B.N. Yeltsin, Yekaterinburg, Russia, and University of Limerick, Ireland, as well as Erasmus Bilateral Exchange between Wroclaw University of Science and Technology, Poland, and University of Limerick, Ireland, 2010–2020 for funding the work on imaging, characterisation and application development using MIR bundle fbres in medicine and manufacturing. JB acknowledges European Commission Erasmus+KA107 Inter-institutional Student and Staf Mobility Programme 2018–2020 between Wroclaw University of Science and Technology, Poland, and Ural Federal University, Yekaterinburg, Russia. SM and AM acknowledges Science Foundation Ireland (SFI) Centre for Medical Devices co-funded under the European Regional Development Fund (Grant Number 13/RC/2073) for characterising bundle fbre. EK, AK and LZ acknowledge Grant No. 18-73-10063 from the Russian Science Foundation for funding the fabrication of fbre bundles.

In this paper, we use a Multiphysics approach in COMSOL™ Platform to develop and validate a finite element model that simulates thermal images obtained in active thermography mode. This approach allows variation in material properties, the selection of active thermography methods such as Flash, Pulse Phase & Lock-in techniques, source wavelength, depth and dimensions of defect. We then take experimental thermography images of a defect embedded into a PLA block to compare with simulated images generated by the Multiphysics model. Our work shows the feasibility of real-time three-dimensional (3D) active infrared thermography (IRT) of buried defects. Such imaging can be hugely beneficial not only in quality control and process optimisation in additive manufacturing but also determination of shape and outline of tumours and plaques in medical applications.

peer-reviewed The full text of this article will not be available in ULIR unti the embargo expires on the 30/03/2021 Elevating and monitoring the temperature of tumors using magnetic nanoparticles (MNPs) still presents a challenge in magnetic hyperthermia therapy. The efficient heating of tumor volume can be achieved by preparing MNPs with high magnetization values. The next-generation approach to magnetic resonance image (MRI)-guided magneto-chemotherapy of cancer based on high-magnetic-moment iron oxide nanoparticles is proposed. The proof of concept is validated by cellular MRI experiments on breast cancer cells. To explore magneto-chemotherapy, we developed high-magnetic-moment iron oxide (Fe3O4) nanoparticles (NPs) using base diisopropylamine (DIPA), which plays a dual role as reducing agent and surface stabilizer. Spherical NPs with ∼12 nm size and a high magnetization value of about 92 emu g–1 at room temperature are obtained by this unique method. A high specific absorption rate value of ∼717 wg–1 was obtained for Fe3O4 NPs in water at an alternating magnetic field of 20 kAm–1 and frequency of 267 kHz, which is attributed to the high magnetization value. The magneto-polymeric micelle structure is formed by using Pluronic F127, and anticancer drug doxorubicin is conjugated in the micelle by electrostatic interactions for magneto-chemotherapy. Finally, the magnetic resonance imaging (MRI)-guided magneto-chemotherapy was achieved on breast cancer (MCF7) cells with an overall ∼96% killing of cancer cells attained in 30 min of magneto-chmeotherapy.

We report a significant spectral drift (up to 110 nm) between optical scattering and extinction in magnetite-gold (Fe3O4-Au) core–shell nanostructures. The drift was observed experimentally using single-particle broadband dark-field scattering microspectroscopy and solution extinction experiments. Infrared thermography demonstrates an enhanced photothermal activity of these nanoparticles at extinction wavelengths that are far drifted from the wavelengths that produce the best results for imaging via scattering. For example, a relatively smooth gold shell leads to 19% more photothermal activity at 532 nm compared to 690 nm whereas a rough-texture, popcorn type morphology gold shell with three times higher drift, is 170% more efficient at 532 nm. We suggest that the enhanced photothermal response results directly from a reduced competition between absorption and scattering as a consequence of the spectral drift. This spectral drift can be advantageous in multimodal theranostics where therapy and imaging are performed independently at different wavelengths.

Research on the piezoelectric response of biomolecules has intensified following demonstration of open circuit voltages of over 20 V in biopiezoelectric generators. Organic piezoelectric nanotubes, fibers, and micro-islands have been grown and studied; however, the lack of fundamental understanding of the piezoelectric effect in nature hinders the rational design of biomaterials to provide a tailor-made piezoelectric response. Advances in high performance computing have facilitated the use of quantum mechanical calculations to predict the full piezoelectric tensor of biomolecular crystals, including amino acids and small peptides. By identifying directions of high piezoelectric response, the simulations can guide experimental crystal growth, device fabrication and electrical testing, which have led to the demonstration of unprecedented piezoelectric responses in organic crystals on the order of 200 pC/N. These large responses arise from strong supramolecular dipoles, which can be tuned by molecular chemistry and packing, opening new opportunities for the realization of technologically useful piezoelectric devices from renewable materials. The amino acids predicted to exhibit the highest piezoelectric response, such as glycine, hydroxyproline and lysine, are anticipated to be used to engineer highly piezoelectric peptides in the future. With improved scaling of advanced computational methods, such as density functional perturbation theory, the research community can begin to efficiently screen peptide structures for enhanced electromechanical properties. This capability will accelerate the experimental development of devices and provide much-needed insight into the evolution of a hierarchical relation in biological materials starting from strongly piezoelectric building blocks. Biological structures such as amino acids, peptides, and proteins are emerging as promising candidates for piezoelectric energy harvesting and sensing. Here we highlight the position of biological materials in the diverse world of piezoelectric structures, and emphasise how a nanoscale insight into these assemblies, particularly in crystalline form, can pave the way for development of a diverse new array of biocompatible sensors for a greener future. By harnessing advances in high performance computing, we can begin to screen the vast library of biomolecules for optimum candidates, with the ultimate goal of re-engineering biological piezoelectricity by first principles design.

Cocrystallization of two or more molecular compounds can dramatically change the physicochemical properties of a functional molecule without the need for chemical modification. For example, coformers can enhance the mechanical stability, processability, and solubility of pharmaceutical compounds to enable better medicines. Here, we demonstrate that amino acid cocrystals can enhance functional electromechanical properties in simple, sustainable materials as exemplified by glycine and sulfamic acid. These coformers crystallize independently in centrosymmetric space groups when they are grown as single-component crystals but form a noncentrosymmetric, electromechanically active ionic cocrystal when they are crystallized together. The piezoelectricity of the cocrystal is characterized using techniques tailored to overcome the challenges associated with measuring the electromechanical properties of soft (organic) crystals. The piezoelectric tensor of the cocrystal is mapped using density functional theory (DFT) computer models, and the predicted single-crystal longitudinal response of 2 pC/N is verified using second-harmonic generation (SHG) and piezoresponse force microscopy (PFM). The experimental measurements are facilitated by polycrystalline film growth that allows for macroscopic and nanoscale quantification of the longitudinal out-of-plane response, which is in the range exploited in piezoelectric technologies made from quartz, aluminum nitride, and zinc oxide. The large-area polycrystalline film retains a damped response of ≥0.2 pC/N, indicating the potential for application of such inexpensive and eco-friendly amino acid–based cocrystal coatings in, for example, autonomous ambient-powered devices in edge computing., Glycine and sulfamic acid form an ionic cocrystal that demonstrates a measurable longitudinal piezoelectric response in single-crystal and polycrystalline form. The crystals are characterized using piezoresponse force microscopy and second harmonic generation, and the material properties are rationalized and quantified using density functional theory calculations.

Realization of a self-assembled, nontoxic and eco-friendly piezoelectric device with high-performance, sensitivity and reliability is highly desirable to complement conventional inorganic and polymer based materials. Hierarchically organized natural materials such as collagen have long been posited to exhibit electromechanical properties that could potentially be amplified via molecular engineering to produce technologically relevant piezoelectricity. Here, by using a simple, minimalistic, building block of collagen, we fabricate a peptide-based piezoelectric generator utilising a radically different helical arrangement of Phe-Phe-derived peptide, Pro-Phe-Phe and Hyp-Phe-Phe, based only on proteinogenic amino acids. The simple addition of a hydroxyl group increases the expected piezoelectric response by an order of magnitude (d35 = 27 pm V−1). The value is highest predicted to date in short natural peptides. We demonstrate tripeptide-based power generator that produces stable max current >50 nA and potential >1.2 V. Our results provide a promising device demonstration of computationally-guided molecular engineering of piezoelectricity in peptide nanotechnology. Piezoelectric materials which are non-toxic and eco-friendly are of interest. Here, the authors report on the creation of collagen-mimetic peptides which can be self-assembled into piezoelectric materials and study the design characteristics required for optimized power generation.

Titania (TiO2) nanoparticles were surface modified using silica and citrate to implement a ‘safe-by-design' approach for managing potential toxicity of titania nanoparticles by controlling surface redox reactivity. DLS and zeta-potential analyses confirmed the surface modification, and electron microscopy and surface area measurements demonstrated nanoscale dimensions of the particles. Electron paramagnetic resonance (EPR) was used to determine the exogenous generation of reactive oxygen species (ROS). All the produced spray dried nanotitania lowered levels of ROS when compared to the corresponding dispersed nanotitania, suggesting that the spray drying process is an appropriate design strategy for the control of nano TiO2 ROS reactivity. The modification of nanotitania with silica and with citrate resulted in increased levels of ROS generation in exogenous measurements, including photoexcitation for 60 minutes. The dichlorodihydrofluorescein (DCFH) assay of dose-dependent production of oxidative stress, generated by pristine and modified nanotitania in macrophages and alveolar epithelial cells, found no significant change in toxicity originating from the generation of reactive oxygen species. Our findings show that there is no direct correlation between the photocatalytic activity of nanotitania and its oxidative stress-mediated potential toxicity, and it is possible to improve the former, for example adding silica as a modifying agent, without altering the cell redox equilibrium.

A combination of chemotherapy with nonconventional nanoparticle based physical destruction therapy has been proposed clinically to reduce the prospect of evolution of drug resistance in cancer. Superparamagnetic nanoparticles have been actively used for synergetic cancer therapy including magnetic fluid hyperthermia (MFH) guided by magnetic resonance imaging (MRI). To explore this direction of potential applications in cancer therapy, we have functionalized superparamagnetic La0.7Sr0.3MnO3 nanoparticles (SPMNPs) with an oleic acid-polyethylene glycol (PEG) polymeric micelle (PM) structure, and loaded it with anticancer cancer drug doxorubicin (DOX) in a high loading capacity (∼60.45%) for in vitro delivery into cancer cells. The micellar structure provided good colloidal stability and biocompatibility. Upon drug loading, the cancer cell death rate of 89% was comparable to free DOX (75%) for 24 h, and that the counterstrategy of DOX conjugated SPMNPs-induced hyperthermia resulted the cancer cell extinction...

Piezoelectric properties of rat tail tendons, sectioned at angles of 0, 59, and 90° relative to the plane orthogonal to the major axis, were measured using piezoresponse force microscopy. The piezoelectric tensor at the length scale of an individual fibril was determined from angle-dependent in-plane and out-of-plane piezoelectric measurements. The longitudinal piezoelectric coefficient for individual fibrils at the nanoscale was found to be roughly an order of magnitude greater than that reported for macroscopic measurements of tendon, the low response of which stems from the presence of oppositely oriented fibrils, as confirmed here. European Commission Horizon 2020 Science Foundation Ireland

The indiscriminate and sporadic use of antibiotics has contributed to the emergence of drug resistance phenomenon in bacteria including but not limited to Staphylococcus aureus. These drug-resistant bacteria have been threatening safety in hospitals and adversely affecting human health. Here we report a strategy to design photo-stimulated theranostic nanoprobes against methicillin-resistant Staphylococcus aureus (MRSA) “superbug” USA300. The nanocapsule probe is based on gold nanorods (GNRs) coated with pegylated thiol, mPEG-SH, which has been further modified by adding successively a natural antibacterial compound such as curcumin, and a cell targeting deoxyribonucleic acid (DNA) aptamer. We have used this novel gold nanocapsules for near-infrared (NIR) photophysical stimulation against pathogenic bacteria. We have found that the novel nanocapsule blocks biofilm formation and kills bacteria by photothermal action that causes disruption of the bacterial cell wall and membrane. In this approach, multiple drug-resistant Staphylococcus aureus has been captured by these nanocapsules through DNA aptamer targeting. All of the trapped bacteria could be killed in 30 minutes during the NIR stimulation due to the combination of photothermal effect, the generation of reactive oxygen species (ROS) and a loss of transmembrane potential (Δψ). Importantly we did not notice any resistance developed against the photothermal treatment. This is remarkable from an anti-biofilm activity point of view. Importantly, these multifunctional nanocapsules have also shown a surface enhanced Raman spectroscopy (SERS) effect, which could be used to evaluate the success of the inactivation effect during treatment. These results indicate that nanocapsule-based photo treatment can be an alternative antibacterial strategy without contributing to antibiotic resistance, and thus can be used for both environmental and therapeutic applications.

Metal-organic frameworks (MOFs) have been at the center stage of material science in the recent past because of their structural properties and wide applications in catalysis. MOFs have also been used as hard templates for the preparation of catalysts. In this study, highly active CuPt/NC electrocatalyst was synthesized by pyrolyzing Cu-tpa MOF along with Pt precursor under flowing Ar-H2 atmosphere. The catalyst was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). Rotating disk electrode study was performed to determine the oxygen reduction reaction (ORR) activity for CuPt/NC in 0.1 M HClO4 at different revolutions per minute (400, 800, 1200, and 1600) and it was also compared with commercial Pt/C catalyst. Further the ORR performance was evaluated by K-L plots and Tafel slope. CuPt/NC shows excellent ORR performance with onset potential of 0.9 V (vs. RHE), which is comparable with commercial Pt/C. The ORR activity of CuPt/NC is demonstrated as an efficient electrocatalyst for fuel cell.

In the present study, the catalytic activity of copper-loaded cobalt-based metal–organic framework (ZIF-67) composites was studied for their electrochemical oxygen reduction reaction (ORR). The Cu-ZIF-67 composite was prepared by the solvothermal method. After pyrolysis under argon atmosphere at 700 °C, the composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The electrochemical activity of the composites was tested for ORR in 0.1 M alkaline media using the three-electrode system by cyclic voltammetry (CV), Tafel plots, and electrochemical impedance spectroscopy (EIS). The composites showed variable activity with a current density of 1.32 mA cm−2 at 0.71 V (versus reversible hydrogen electrode (RHE)) onset potential for 70 wt% Cu-ZIF-67, 7.5 mA cm−2 at 0.82 V (versus RHE) onset potential for 50 wt% Cu-ZIF-67, and 11.85 mA cm−2 at 0.85 V (versus RHE) for 30% Cu-ZIF-67. The increasing ratio of the ZIF-67 effect can be attributed to the increased activity of ZIF-67 with the synergistic effect of Cu toward increased current density.

peer-reviewed Noble-metal nanoparticles size and packing density are critical for sensitive surface-enhanced Raman scattering (SERS) and controlled preparation of such films required to achieve reproducibility. Provided that they are made reliable, Ag shell on SiO2 microscopic particles (Ag/SiO2) are promising candidates for lab-on-a-bead analytical measurements of low analyte concentration in liquid specimen. Here, we selected nanoporous silica microparticles as a substrate for reduction of AgNO3 with 3-aminopropyltriethoxysilane (APTES). In a single preparation step, homogeneous and continuous films of Ag nanoparticles are formed on SiO2 surfaces with equimolar concentration of APTES and silver nitrate in ethanol. It is discussed that amine and silane moieties in APTES contribute first to an efficient reduction on the silica and second to capping the Ag nanoparticles. The high density and homogeneity of nanoparticle nucleation is further regulated by the nanoporosity of the silica. The Ag/SiO2 microparticles were tested for SERS using self-assembled 4-aminothiophenol monolayers, and an enhancement factor of ca. 2 × 106 is measured. Importantly, the SERS relative standard deviation is 36% when a single microparticle is considered and drops to 11% when sets of 10 microparticles are considered. As prepared, the microparticles are highly suitable for state-of-the-art quantitative lab-on-a-bead interrogation of specimens.

The symmetry of orthorhombic amino acid single crystals precludes the existence of a longitudinal piezoelectric response. Here we report the growth of amino acid crystal films on conductive substra...

Here we report a preliminary quantitative investigation into calcite piezoelectricity using a combination of quantum mechanical modelling and electromechanical characterisation of naturally occurring calcite crystals and structures. The low symmetry of crystallised biomolecules — from amino acids and peptides to viruses and fibrous proteins — can result in useful electrical properties, including ferroelectricity, pyroelectricity, and piezoelectricity. Biominerals such as hydroxyapatite and calcite are generally not considered piezoelectric. This data represents the first quasi-static, longitudinal piezoelectric measurements on macroscopic calcite based materials; namely Icelandic spar and a variety of beach specimens. We substantiate these measurements using Density Functional Theory (DFT) calculations, which attribute the measured weak, residual piezoelectric response in all directions to centrosymmetric calcite crystals. Our data is consistent with the observation of second harmonics generation by calcite microcrystals occurring in the human pineal gland.

Nanometrology refers to measurement techniques that assess materials properties at the nanoscale. Laboratory-based characterisation of nanomaterials has been the key enabler in the growth of nanotechnology and nano-enabled products. Due to the small size involved, dimensional measurements has dominated such characterisation underpinned by a tremendous development in stand-alone electron/ion microscopes and scanning probe microscopes.However, the scope of nanometrology extends far beyond off-site, laboratory-based measurements of dimensions only, and is expected to have a tremendous impact on design of nano-enabled materials and devices.In this article, we discuss some of the available techniques for laboratory-based characterisation of mechanical and interfacial properties for nanometrology. We also provide a deep insight into the emerging techniques in measuring these properties, keeping in view the need in advanced manufacturing and nanobio-interactions to develop multifunctional instrumentation, traceable and standardized methods, and modelling tools for unambiguous data interpretation.We also discuss the evaluation of nanomechanical properties and surface/interface response of materials, within the purview of manufacturing processes and standardization.Finally, we discuss scientific and technological challenges that are required to move towards real-time nano-characterisation for rapid, reliable, repeatable and predictive metrology to underpin upscaling nanomaterials and nano-enabled products from the research field to industry and market. Keywords: Nanometrology, Nanoindentation, AFM, Bio, Microscopy, Nanoscopy

Additive manufacturing (AM) is fundamentally different from traditional formative or subtractive manufacturing in that it is the closest to the ‘bottom up’ manufacturing where a structure can be built into its designed shape using a ‘layer-by-layer’ approach rather than casting or forming by technologies such as forging or machining. AM is versatile, flexible, highly customizable and, as such, can suite most sectors of industrial production. Materials to make these parts/objects can be of a widely varying type. These include metallic, ceramic and polymeric materials along with combinations in the form of composites, hybrid, or functionally graded materials (FGMs). The challenge remains, however, to transfer this ‘making’ shapes and structures into obtaining objects that are functional. A great deal of work is needed in AM in addressing the challenges related to its two key enabling technologies namely ‘materials’ and ‘metrology’ to achieve this functionality in a predictive and reproductive ways. The good news is that there is a significant interest in industry for taking up AM as one of the main production engineering route. Additive Manufacturing, in our opinion, is definitely at the cross-road from where this new, much-hyped but somewhat unproven manufacturing process must move towards a technology that can demonstrate the ability to produce real, innovative, complex and robust products.

The discovery of piezoelectricity in calcined thin films and sintered ceramics of synthetic hydroxyapatite is of interest to understand the role of electricity in bone growth and to find use of piezoelectric implants in bone growth stimulation or deceleration and in energy harvesting to run spinal or neuro stimulators. Synthetic apatites including hydroxyapatite and a mixture of hydroxyapatite and tricalcium phosphates are extensively used in bone graft substitute and cement-less implant coating. We provide experimental evidence of piezoelectricity in screen-printed thick-films of hydroxyapatite, which may allow many real-time experiments to understand physiological significance of piezoelectricity and potential in vivo exploitation.

The main objective of this work was to investigate the thermomechanical behavior and microstructural changes of a Ti-rich NiTi shape memory alloy (SMA). The microstructural and texture evolution of aged NiTi alloy at different degrees of deformation were elicited by transmission electron microscopy (TEM). An effort was made to correlate results obtained from the tensile test with results from microstructure studies. The undeformed sample reveals a self-accommodated morphology with straight and well defined twin boundaries. At different stages of deformation, diverse mechanisms were involved. These mechanisms include marstraining, detwinning accompanied by dislocation movement, and finally, severe plastic deformation, subdivision and amorphization of the matrix. Under increasing strains, high density lattice defects were generated and the morphology of B19’ became disordered.

Bioinspired assemblies bear massive potential for energy generation and storage. Yet, biological molecules have severe limitations for charge transfer. Here, we report l-tryptophan-d-tryptophan assembling architectures comprising alternating water and peptide layers. The extensive connection of water molecules results in significant dipole–dipole interactions and piezoelectric response that can be further engineered by doping via iodine adsorption or isotope replacement with no change in the chemical composition. This simple system and the new doping strategies supply alternative solutions for enhancing charge transfer in bioinspired supramolecular architectures.

Amino acid chirality plays an important role in conveying directionality and specificity to their supramolecular organization. However, the impact of enantiopure and racemic amino acids on the favorable packing and macroscopic properties of organic cocrystals with nonchiral coformers is poorly understood. Herein, we performed a systematic study of the effect of chirality on the macroscopic properties of acetylated alanine (AcA) single crystals and cocrystals with a nonchiral photo-sensitive bipyridine derivative (BPE). Cocrystallization with BPE produced a marked morphology transition that improved the supramolecular chirality, thermal stability and mechanical strength of AcA crystals. The distinct supramolecular packing modes were analyzed by X-ray crystallography. The highest rigidity was observed for BPE/ dl -AcA, while BPE/ d -AcA and BPE/ l -AcA crystals exhibited higher efficiency of photo-induced emission for fluorescent imprinting, as well as significantly higher piezoelectricity. This work provides a striking illustration that subtle differences in amino acid stereochemistry translate into tunable macroscopic properties of organic cocrystals for future applications in rigid solids, fluorescent imprinting, and energy harvesting.

peer-reviewed In the nanometric regime, alumina films are often deposited by ALD methods yet in industrial applications, sputtered films thinner than 40 nm are used and research into those is sparse. Here, we investigated the nanoscale topography and the electrical properties of films less than 10 nm thick deposited by direct RF magnetron sputtering. Alumina films deposited on Si appeared to be uniform and topographically defect free as evaluated by TEM and AFM. However, their composition varied as a function of thickness as measured by XPS. The films were non-stoichiometric as Al content increased with film thickness. While SSRM measured current profiles did not highlight leakage sites or voids in the films, KPFM measured local charge fluctuations across the films deposited on Si and Au surfaces. The density of fluctuation sites decreased with an increase of alumina thickness. An electrodeposition method identified insulation weak spots in the alumina where Cu growths formed on the alumina surface. The growth mechanisms were investigated by TEM and EDX. The density of growths decreased with increased alumina thickness. Defects in the deposited alumina film are expected to be due to its nonstoichiometric nature causing charge variations, which weaken the films electrical insulating capability.

peer-reviewed Despite the presence of over 56% Ni by weight, equiatomic NiTi is generally considered biocompatible as it naturally oxidises to form a surface oxide mainly composed of biocompatible oxides of titanium (TiOx). This layer is formed by an oxidation mechanism that promotes out-diffusion of Ti leaving a Ti-depleted, Ni rich subsurface.The long-term in vivo stability of the naturally grown Ti Oxlayer has been a concern as Ni can leach out through this thin, defective layer. The leaching of nickel (Ni) is thus a continuing threat to the alloy’s other wise outstanding bio compatibility. We have found that a layer of reactively sputtered tantalum(Ta)oxide on the bulk NiTi restricts Ti-out-migration through a biocompatible Ti/Tainter-diffusion layer that provides a larger barrier against Ni leaching. We have investigated this inter-diffusion as a function of sputtering process parameters and post processing treatments. Surface and interface analytical techniques such as X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, cross sectional transmission electron microscopy and non-destructive ion beam analysis techniques such as Rutherford backscattering spectrometry and particle induced X-ray emission were used to evaluate the nature of this interdiffusion layer which can improve long-term biocompatibility of NiTi

Diphenylalanine (FF) represents the simplest peptide building block that self-assembles into ordered nanostructures with interesting physical properties. Among self-assembled peptide structures, FF nanotubes display notable stiffness and piezoelectric parameters (Young’s modulus = 19–27 GPa, strain coefficient d33 = 18 pC/N). Yet, inorganic alternatives remain the major materials of choice for many applications due to higher stiffness and piezoelectricity. Here, aiming to broaden the applications of the FF motif in materials chemistry, we designed three phenyl-rich dipeptides based on the β,β-diphenyl-Ala-OH (Dip) unit: Dip-Dip, cyclo-Dip-Dip, and tert-butyloxycarbonyl (Boc)-Dip-Dip. The doubled number of aromatic groups per unit, compared to FF, produced a dense aromatic zipper network with a dramatically improved Young’s modulus of ∼70 GPa, which is comparable to aluminum. The piezoelectric strain coefficient d33 of ∼73 pC/N of such assembly exceeds that of poled polyvinylidene-fluoride (PVDF) polymers and compares well to that of lead zirconium titanate (PZT) thin films and ribbons. The rationally designed π–π assemblies show a voltage coefficient of 2–3 Vm/N, an order of magnitude higher than PVDF, improved thermal stability up to 360 °C (∼60 °C higher than FF), and useful photoluminescence with wide-range excitation-dependent emission in the visible region. Our data demonstrate that aromatic groups improve the rigidity and piezoelectricity of organic self-assembled materials for numerous applications.

Progress in nanomedicine has enabled the development of smart hybrid nanostructures (HNSs) for brain cancer theranostics, a novel platform that can diagnose the brain while concurrently beginning primary treatment, initiating secondary treatments where necessary, and monitoring the therapy response. These HNSs can release guest molecules/cargoes directly to brain tumors in response to external physical stimuli. Such physical stimulation is generally referred to as remote stimuli which can be externally applied examples include alternating magnetic field, visible or near-infrared light, ultrasound radiation, X-ray, and radiofrequency. The release of therapeutic cargoes in response to physical stimuli can be performed along with photodynamic therapy, photothermal therapy, phototriggered chemotherapeutics, sonodynamic therapy, electrothermal therapy, and magnetothermal therapy. Herein, we review different HNSs currently used as remotely triggered modalities in brain cancer, such as organic-inorganic HNSs, polymer micelles, and liposomes HNSs. We also summarize underlying mechanisms of remote triggering brain cancer therapeutics including single- and two-photon triggering, thermoresponsive HNSs, photoresponsive HNSs, magnetoresponsive HNSs, and electrically and ultrasound-stimulated HNSs. In addition to a brief synopsis of ongoing research progress on "smart" HNSs-based platforms of novel brain cancer therapeutics, the review offers an up-to-date development in this field for neuro-oncologists, material/nanoscientists, and radiologists so that a rapid clinical impact can be achieved through a convergence of multidisciplinary expertise.

Background A thorough understanding of cutting-edge geometry and cutting forces of hollow biopsy needles are required to optimise needle tip design to improve fine needle aspiration procedures. Objectives To incorporate the dynamics of needle motion in a model for flexible hollow bevel tipped needle insertion into a biological mimetic soft-gel using parameters obtained from experimental work. Additionally, the models will be verified against corresponding needle insertion experiments. Methods To verify simulation results, needle deflection and insertion forces were compared with corresponding experimental results acquired with an in-house developed needle insertion mechanical system. Additionally, contact stress distribution on needles from agar gel for various time scales were also studied. Results For the 15°, 30°, 45°, 60° bevel angle needles, and 90° blunt needle, the percentage error in needle deflection of each needle compared to experiments, were 7.3%, 9.9%, 8.6%, 7.8%, and 9.7% respectively. Varying the bevel angle at the needle tip demonstrates that the needle with a lower bevel angle produces the largest deflection, although the insertion force does not vary too much among the tested bevel angles. Conclusion This experimentally verified computer-based simulation model could be used as an alternative tool for better understanding the needle-tissue interaction to optimise needle tip design towards improved biopsy efficiency.

Cancer cells become resistant over the period to chemotherapeutic drugs and pose a challenging impediment for oncologists in providing effective treatment. Nanomedicine allows to overcome chemoresistance and is the focus of our investigation. Silica nanostructures have been highlighted as an interesting drug delivery platform in vitro and in vivo applications. Here we show the validity of nanomedicine approach for targeted chemotherapeutic cargo delivery to overcome chemoresistance in cancer cells both in vitro and in vivo. For demonstrating the concept, we functionalised ∼100 nm long porous silica nanoparticles (∼20 nm diameter ordered pore structure) by conjugating anticancer drug, cytochrome c enzyme and dual-function anticancer aptamer AS1411 in single supra-assembled nanocargos. The supra-assembly on the porous silica nanostructure allows for a high loading of catalytic enzyme cytochrome c, anticancer drug and aptamer. The silica supra-assembly is characterized by transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) surface area analysis. Conjugation of cargoes has been monitored at each step by UV–vis and Fluorescence spectroscopy. Finally, the constructed supra-assembled nanocarrier tested on chemoresistance colon cancer (HCT116) cells. A pH-responsive, intracellular theranostic cargo delivery has been achieved and the triple action of the nanocargo made an efficient killing of drug resistance colon cancer cells in vitro (∼ 92% cell death) through triplex therapy effects by supressing the P-glycoprotein (P-gp) level. Furthermore, in vivo animal toxicity studies demonstrated, the supra-assembled nanocargos have encouraging safety index to be used in cancer therapy and drug delivery applications.

peer-reviewed Analysis of the cellular response to piezoelectric materials has been driven by the discovery that many tissue components exhibit piezoelectric behavior ex vivo. In particular, polyvinylidene fluoride and the trifluoroethylene co-polymer (PVDF-TrFE) have been identified as promising piezo and ferroelectric materials with applications in energy harvesting and biosensor devices. Critically, the modulation of the structural and crystalline properties of PVDF-TrFE through annealing processes and the addition of particulate or fibrous fillers has been shown to modulate significantly the materials electromechanical properties. In this study, a PVDF-TrFE/boron-nitride nanotube composite was evaluated by modulated differential scanning calorimetry to assess the effects of boron nitride nanotube addition and thermal annealing on the composite structure and crystal behavior. An increased beta crystal formation [f(b) = 0.71] was observed following PVDF-TrFE annealing at the first crystallization temperature of 120◦C. In addition, the inclusion of boron nitride nanotubes significantly increased the crystal formation behavior [f(b) = 0.76] and the mechanical properties of the material. Finally, it was observed that BNNT incorporation enhance the adherence and proliferation of human tenocyte cells in vitro.

The development of an electrochemical biosensor utilising a hairpin DNA probe labelled with methylene blue for the detection of the TP53 gene is described. Structural rearrangement of the hairpin probe into a linear double DNA strand induced different rates of electron transfer that enabled an increase in current upon hybridization. The increase in current observed upon hybridization was studied at different surface probe densities, hybridization times, concentration and length of target DNA sequences. The biosensor selectively detected a single nucleotide polymorphism in the TP53 gene affecting residue 175 of the p53 protein, with the response more pronounced at shorter hybridization times. Detection of target DNA sequences at nanomolar concentrations was achieved and the sensor possessed good operational and storage stability.

The ability to reliably measure electromechanical properties is crucial to the advancement of materials design for applications in fields ranging from biology and medicine to energy storage and electronics. With the relentless miniaturization of device technology, the ability to perform this characterization on the nanoscale is paramount. Due to its ability to probe electromechanical properties on the micro- and nano-scales, piezoresponse force microscopy (PFM) has become the premier tool for piezoelectric and ferroelectric characterization of a new generation of smart, functional materials. Despite its widespread use and popularity, PFM is a highly nuanced technique, and measurements on similar samples using different machines and/or in different laboratories often fail to agree. A comprehensive protocol for accurate quantitative measurements has not been presented in the literature, slowing the general uptake of the technique by reducing the ability of research groups to take full advantage of PFM for their characterization needs. Here, we present a procedure for PFM measurements, which outlines the practical aspects of quantitative PFM, from sample preparation to probe choice and use of control samples, and we substantiate these steps with original data on lithium niobate control samples. This quantitative characterization protocol is critical as society looks to smaller, greener alternatives to traditional piezoelectric materials for applications such as drug delivery, bio-microelectromechanical system sensors and actuators, and energy harvesting.

Magnetic-plasmonic, Fe3O4-Au, core-shell nanoparticles are popular in many applications, most notably in therapeutics and diagnostics, and thus, the imaging of these nanostructures in biological samples is of high importance. These nanostructures are typically imaged in biological material by dark field scatter imaging, which requires an even distribution of nanostructures in the sample and, therefore, high nanoparticle doses, potentially leading to toxicology issues. Herein, we explore the nonlinear optical properties of magnetic nanoparticles coated with various thicknesses of gold using the open aperture z-scan technique to determine the nonlinear optical properties and moreover, predict the efficacy of the nanostructures in nonlinear imaging. We find that the magnetic nanoparticles coated with gold nanoseeds and thinner gold shells (ca. 4 nm) show the largest nonlinear absorption coefficient β and imaginary part of the third-order susceptibility Im χ(3), suggesting that these nanostructures would be suitable contrast agents. Next, we combine laser dark field microscopy and epi-detected coherent anti-Stokes Raman (CARS) microscopy to image the uptake of magnetic-plasmonic nanoparticles in human pancreatic cancer cells. We show the epi-detected CARS technique is suitable for imaging of the magnetic-plasmonic nanoparticles without requiring a dense distribution of nanoparticles. This technique achieves superior nanoparticle contrasting over both epi-detected backscatter imaging and transmission dark field imaging, while also attaining label-free chemical contrasting of the cell. Lastly, we show the high biocompatibility of the Fe3O4 nanoparticles with ca. 4-nm thick Au shell at concentrations of 10–100 µg/mL.

A method is proposed to overcome the diffraction limit of spatial resolution in infrared microscopy. To achieve this, standing waves in an attenuated total reflection configuration were generated to spatially modulate the absorbance of adsorbate vibrational transitions. A numerical simulation was undertaken. It showed that chemical imaging with a spatial resolution of approximately 100 nm is achievable in the case of self-assembled patterns (ofoctdecyltrichlorosilane [CH3-(CH2)17-SiCl3]), when probing the methyl modes located near 3.5 micrometres.

To achieve light-triggered drug release in cancer chemotherapy, we developed multimodal titanium dioxide (TiO2) nanocorals modified with methoxy polyethylene glycol (mPEG). TiO2 nanocoral-like structures were synthesized by optimizing a solvothermal method. The developed nanocoral structures were efficiently conjugated with chemotherapeutic drugs on the surfaces of the TiO2 nanoparticles. The mPEG on the surfaces of the multifunctional nanocorals effectively conjugated the drug and improved the biocompatibility of the nanocorals. Following UV light irradiation, the TiO2 nanocorals produce free radicals (˙OH and ˙O2−) and are effective for drug release in cancer cells. Importantly, the amount of drug released from the multimodal TiO2 nanocorals can be regulated by UV-light irradiation time, which allows for further control of the anti-cancer effect. The multimodal TiO2 nanocorals exhibit a combination of light-activated, stimuli-triggered drug release for killing of cancer cell. The cytotoxicity, cellular uptake, and intracellular location of the formulations were evaluated in MCF7 cells. Our results showed that nanocoral–DOX complexes exhibited a greater cytotoxicity toward MCF7 cells than free DOX. Our work demonstrates that the therapeutic efficacy of DOX-loaded TiO2 nanocorals is strongly dependent on their loading mode and the chemotherapeutic effect is improved under UV light illumination, which provides a significant breakthrough for future applications of TiO2 as a light activated drug carrier in cancer chemotherapy.

Nanoparticles are defined as solid colloidal particles ranging in size from 10 to 1000 nm. Nanoparticles offer many benefits to larger particles such as increased surface-to-volume ratio and increased magnetic properties. Over the last few years, there has been a steadily growing interest in using nanoparticles in different biomedical applications such as targeted drug delivery, hyperthermia, photoablation therapy, bioimaging and biosensors. Iron oxide nanoparticles have dominated applications, such as drug delivery, hyperthermia, bioimaging, cell labelling and gene delivery, because of their excellent properties such as chemical stability, non-toxicity, biocompatibility, high saturation magnetisation and high magnetic susceptibility. In this review, nanoparticles will be classified into four different nanosystems metallic nanoparticles, bimetallic or alloy nanoparticles, metal oxide nanoparticles and magnetic nanoparticles. This review investigates the use of nanosystems other than iron oxide nanoparticles such as metallic nanoparticles like gold (Au) and silver (Ag), bimetallic nanoparticles like iron cobalt (Fe-Co) and iron platinum (Fe-Pt) and metal oxides including titanium dioxide (TiO2) cerium dioxide (CeO2), silica (SiO2) and zinc oxide (ZnO) with a focus on the lesser studied nanoparticles such as silver (Ag), iron-platinum (Fe-Pt) and titanium dioxide (TiO2) and how their unique properties allow for their potential use in various biomedical applications.

Classical Grand Canonical Monte Carlo (GCMC), classical molecular dynamics (MD), and density functional theory (DFT) have been employed to study the effect of pore-size and pore-chemistry on the adsorption of carbon dioxide in the SIFSIX-3-M family of hybrid ultramicroporous materials (HUMs), where M = Zn2+, Ni2+, or Cu2+. These HUMs have been shown to exhibit exceptional affinity toward small polarizable molecules such as CO2, and our simulated isotherms are in good agreement with those obtained experimentally. Isosteric heats of adsorption (Qst) calculated using these theoretical methods also follow the experimentally observed trend, decreasing as M varies from Cu to Ni to Zn in SIFSIX-3-M. More specifically, the interaction energy between a CO2 molecule and HUMs with varying pore-size was calculated using a DFT-D2 level of theory. The strongest interaction energy was calculated for SIFSIX-3-Cu (56.89 kJ mol–1) where the pore-size is the smallest. The interaction energy decreased in SIFSIX-3-Ni (52.21 k...

Superparamagnetic nanoparticles (SPMNPs) used for magnetic resonance imaging (MRI) and magnetic fluid hyperthermia (MFH) cancer therapy frequently face trade off between a high magnetization saturation and their good colloidal stability, high specific absorption rate (SAR), and most importantly biological compatibility. This necessitates the development of new nanomaterials, as MFH and MRI are considered to be one of the most promising combined noninvasive treatments. In the present study, we investigated polyethylene glycol (PEG) functionalized La1-xSrxMnO3 (LSMO) SPMNPs for efficient cancer hyperthermia therapy and MRI application. The superparamagnetic nanomaterial revealed excellent colloidal stability and biocompatibility. A high SAR of 390 W/g was observed due to higher colloidal stability leading to an increased Brownian and Neel's spin relaxation. Cell viability of PEG capped nanoparticles is up to 80% on different cell lines tested rigorously using different methods. PEG coating provided excellent hemocompatibility to human red blood cells as PEG functionalized SPMNPs reduced hemolysis efficiently compared to its uncoated counterpart. Magnetic fluid hyperthermia of SPMNPs resulted in cancer cell death up to 80%. Additionally, improved MRI characteristics were also observed for the PEG capped La1-xSrxMnO3 formulation in aqueous medium compared to the bare LSMO. Taken together, PEG capped SPMNPs can be useful for diagnosis, efficient magnetic fluid hyperthermia, and multimodal cancer treatment as the amphiphilicity of PEG can easily be utilized to encapsulate hydrophobic drugs.

An investigation was carried out into the influence of the annealing temperatures on the thermo-mechanical behavior of Ti-rich NiTi alloy with regard to transformation temperatures, mechanical properties at room temperature and microstructure evolution under deformation. It was found that annealing above the recrystallization temperature (600 °C) modulated the mechanical behavior of the alloy significantly. Based on tensile and DSC analysis, it was observed that by increasing the annealing temperature, the shape memory behavior of the alloys improved. Scanning and transmission electron microscopy were used to investigate the fracture surfaces and microstructural evolution of the NiTi samples after failure. Fractography revealed the brittle fracture area produced through the propagation of cleavage cracks; however, ductile fracture via nucleation growth and coalescence of micro-dimples in the martensitic phase at room temperature were also observed. During plastic deformation, the NiTi alloy was also observed to undergo a detwinning process, dislocation slip and the formation of submicrocrystalline grains, nanocrystallization and amorphous bands.

Binary NiTi alloy is one of the most important biomaterials currently used in minimally invasive procedures and indwelling devices. The poor visibility of intermetallic NiTi under X-ray could be an unsatisfactory feature especially for developing low-dimensional implantable devices for the body. It is a matter of fact that the alloying of a third radiopaque element, such as noble or heavy metals, in NiTi can significantly enhance the alloy's radiopacity. Recently, it was demonstrated that the addition of a rare earth element such as Erbium has led to an equivalent radiopacity at a much lower cost than the equivalent addition of noble metals. This work reviews the main physical aspects related to the radiopacity of NiTi alloys and compares the radiopacity of NiTi-Er compositions with other NiTi-based alloys containing Pd, Pt, W and Cr. Furthermore, a NiTi-6Er alloy is produced by spark plasma sintering, and successfully processed by conventional hot and cold working procedures to a continuous wire showing stable superelastic behaviour (up to 4 % in strain), suitable for developing biomedical devices.

Biomolecular crystals are an emerging class of piezoelectric materials that are both biocompatible and biodegradable, which enables their use in biomedical applications and smart devices while ensuring eco-friendly production and disposal. However, accurate quantification of the piezoelectric response of soft sub-micron crystals remains a significant challenge, as conventional piezoelectric measurement techniques are suited to ceramics, thin films, and polymers. Here, we demonstrate the use of a novel piezoresponse force microscopy (PFM) methodology for robust, reliable quantification of the electromechanical response of biomolecular crystals. As a strong test of high accuracy and precision, we show that PFM, integrated with quantum mechanical (QM) density functional theory (DFT) calculations, can distinguish the piezoelectric responses of near-isopiezoelectric amino acid crystals. We show that a statistical approach, combined with experimental best practices, provides effective piezoelectric coefficients of biomolecular single crystals accurately and unambiguously. This work opens the door to high-throughput screening and characterisation of natural and engineered soft piezoelectric crystals for eco-friendly energy harvesters and biodegradable medical implants, reducing dependence on lead-based and rare-earth-containing piezoelectric materials.

In this study, we have synthesized Ti(1-x)SmxO2 (x = 0–20%) nanocomposites by adopting an aqueous sol-gel route. A two or multi-phase mixture of titania and samarium oxide could be expected as samarium added >5% may exceed its solubility limit in anatase. Surface and high-resolution characterization found Sm forming a predominantly thin amorphous layer that is not discernible in conventional transmission electron microscopy. The addition of Sm in such a high amount stabilizes formation of anatase phase of TiO2. Importantly, we observe that the incorporation of such high amount of Sm in titania leads to a grain growth inhibition of anatase. Sm can also be reduced from a trivalent state to a bivalent state. The addition of Sm thus results in very thin amorphous layer around the nanocrystalline anatase, inhibits the growth of this anatase and lowers the indirect band gap from 3.0 eV to 2.47 eV. That such lowering happens along with a lowering of size and a resulting increase in surface area means that doping of titania by more than 5% Sm can make better a photocatalyst either for the purpose of photodegradation of industrial organic water-pollutants and microorganisms under the visible light irradiation than a pristine anatase.

Second-harmonic generation (SHG) is a nonlinear optical process that can provide disease diagnosis through characterization of biological building blocks such as amino acids, peptides, and proteins. The second-order nonlinear susceptibility tensor χ(2) of a material characterizes its tendency to cause SHG. Here, a method for finding the χ(2) elements from polarization-resolved SHG microscopy in transmission mode is presented. The quantitative framework and analytical approach that corrects for micrometer-scale morphology and birefringence enable the determination and comparison of the SHG susceptibility tensors of β- and γ-phase glycine microneedles. The maximum nonlinear susceptibility coefficients are d33 = 15 pm V-1 for the β and d33 = 5.9 pm V-1 for the γ phase. The results demonstrate glycine as a useful biocompatible nonlinear material. This combination of the analytical model and polarization-resolved SHG transmission microscopy is broadly applicable for quantitative SHG material characterization and diagnostic imaging.

Optical properties of metal nanostructures, governed by the so-called localised surface plasmon resonance (LSPR) effects, have invoked intensive investigations in recent times owing to their fundamental nature and potential applications. LSPR scattering from metal nanostructures is expected to show the symmetry of the oscillation mode and the particle shape. Therefore, information on the polarisation properties of the LSPR scattering is crucial for identifying different oscillation modes within one particle and to distinguish differently shaped particles within one sample. On the contrary, the polarisation state of light itself can be arbitrarily manipulated by the inverse designed sample, known as metamaterials. Apart from polarisation state, external stimulus, e.g., magnetic field also controls the LSPR scattering from plasmonic nanostructures, giving rise to a new field of magneto-plasmonics. In this review, we pay special attention to polarisation and its effect in three contrasting aspects. First, tailoring between LSPR scattering and symmetry of plasmonic nanostructures, secondly, manipulating polarisation state through metamaterials and lastly, polarisation modulation in magneto-plasmonics. Finally, we will review recent progress in applications of plasmonic and magneto-plasmonic nanostructures and metamaterials in various fields.

This chapter aims to identify gaps in our understanding of current strengths of hybrid nanostructures in theranostics to fulfill its promise in prolonging patient survival, and to offer an overview of our current grasp of the preclinical and clinical stages of nanostructures in cancer. The chapter starts with a brief discussion of the current clinical and preclinical stages of hybrid nanostructures. Subsequently, we provide a comprehensive compilation of recent representative studies in this field, which is organized depending on the proposed clinical applications. We focus on the integration of organic–inorganic interfaces for the development of cancer therapies based on hybrid nanostructures.

Peptide assemblies are ideal components for eco-friendly optoelectronic energy harvesting devices due to their intrinsic biocompatibility, ease of fabrication, and flexible functionalization. However, to date, their practical applications have been limited due to the difficulty in obtaining stable, high-performance devices. Here, it is shown that the tryptophan-based simplest peptide cycloglycine-tryptophan (cyclo-GW) forms mechanically robust (elastic modulus up to 24.0 GPa) and thermally stable up to 370 °C monoclinic crystals, due to a supramolecular packing combining dense parallel β-sheet hydrogen bonding and herringbone edge-to-face aromatic interactions. The directional and extensive driving forces further confer unique optical properties, including aggregation-induced blue emission and unusual stable photo-luminescence. Moreover, the crystals produce a high and sustained opencircuit voltage (1.2 V) due to a high piezoelectric coefficient of 14.1 pC N(−1). These findings demonstrate the feasibility of utilizing self-assembling peptides for fabrication of biointegrated microdevices that combine high structural stability, tailored optoelectronics, and significant energy harvesting properties.

As the industry and commercial market move towards the optimization of printing and additive manufacturing, it becomes important to understand how to obtain the most from the materials while maintaining the ability to print complex geometries effectively. Combining such a manufacturing method with advanced carbon materials, such as Graphene, Carbon Nanotubes, and Carbon fibers, with their mechanical and conductive properties, delivers a cutting-edge combination of low-cost conductive products. Through the process of printing the effectiveness of these properties decreases. Thorough optimization is required to determine the idealized ink functional and flow properties to ensure maximum printability and functionalities offered by carbon nanoforms. The optimization of these properties then is limited by the printability. By determining the physical properties of printability and flow properties of the inks, calculated compromises can be made for the ink design. In this review we have discussed the connection between the rheology of carbon-based inks and the methodologies for maintaining the maximum pristine carbon material properties.

Fast, label-free optical identification and quantification of biomolecules and other relevant biological materials in microfluidic devices and the vascular system will play a major role in liquid biopsy and related diagnoses. An optical microscope probing simultaneously non-linear coherent anti-Stokes Raman scattering (CARS) and linear scattering (LS) was used to probe microparticles in aqueous solutions flowed unconstrained in microfluidic channels. Despite the optical complexity of these systems, where out-of-focus microparticles randomly impede CARS and LS, and where water CARS generates a substantial background, we demonstrate that in-focus microparticles can be individually and unambiguously detected when CARS and LS are co-analyzed. The ability to chemically discriminate microscale features in optically realistic flows supports the relevance of multimodal CARS platforms for liquid biopsy.