Nanoscale Level Research Articles

Nanostructuring of Ferritic Steel: A Review on Enhanced Surface Properties Using Ultrasonic Shot Peening

Nanostructuring of ferritic stainless steel refers to the process of intentionally reducing the grain size of the material at the nanoscale level. By manipulating the microstructure of the steel, it is possible to enhance its mechanical, physical, and chemical properties. Nanostructuring can significantly improve the strength, hardness, and wear resistance of ferritic stainless steel, while still maintaining its corrosion resistance. The increased density of grain boundaries and the complex dislocation network within the nanostructured material contribute to these improved properties. Moreover, the nanostructured ferritic stainless steel exhibits enhanced thermal stability, leading to better high-temperature performance and resistance to creep deformation. The small grain size also allows for increased precipitation of secondary phases, such as carbides, nitrides, or intermetallic compounds, which can further improve the material's properties. There are several methods to achieve nanostructuring in ferritic stainless steel, such as severe plastic deformation (SPD) techniques like high-pressure torsion, equal channel angular pressing, and accumulative roll bonding. These techniques impose extreme plastic deformation on the material. Leading to grain refinement below the micrometre range. Also, a novel method of surface nanostructuring ultrasonic shot peening (USP) is discussed in detail. Shot peening is a process in which small, spherical media, typically made of steel or ceramic, called "shots," are propelled onto the surface of a material at high velocities. Ultrasonic shot peening enhances the traditional shot peening process by introducing high-frequency vibrations to the shots. These vibrations are generated by an ultrasonic transducer, which is immersed in a bath of shots and liquid. The vibrations are transmitted through the liquid to the shots, causing them to collide with the surface of the ferritic steel at even higher velocities and energy levels than in traditional shot peening. In summary, nanostructuring of ferritic stainless steel offers great potential for tailoring the material's properties to meet specific application requirements, including improved strength, hardness, wear resistance, corrosion resistance, and high-temperature performance. USP is an effective surface treatment method for ferritic steel, offering advantages in terms of fatigue life, stress corrosion cracking resistance, surface hardness, and wear resistance.

BODIPY-Based NIR Trackers with Acidity-Driven Amphiphilicity for STED Super-Resolution Imaging of Lysosomal Membranes.

Although super-resolution imaging provides a great opportunity to disclose the structures of living cells at the nanoscale level, resolving the structural details of organelles is highly dependent on the targeting accuracy and photophysical properties of fluorescence trackers. Herein, we report a series of ultrabright and photostable trackers of lysosomal membranes for super-resolution imaging using stimulated emission depletion microscopy (STED). These trackers are composed of lipophilic NIR BODIPY derivatives and ionizable tertiary amines. This structural feature enables accurate targeting of the lysosomal membrane through the formation of transient amphiphilicity driven by the acidity in the lysosome. As a representative, Lyso-700 is applied for STED-based super-resolution imaging of the lysosomal membrane of living macrophages. By use of Lyso-700, the interaction details between lysosomes of macrophages and fungi are visualized. Overall, these trackers display great potential as advanced lysosome trackers and merit further evaluation for lysosome-related studies.

Insights into uranium sequestration by coal fly-ash-derived zeolites: Understanding via wet chemistry, and advanced spectroscopies

The operation of nuclear power plants requires a supply of nuclear fuel where uranium plays a substantial role as a primary fissile material. Its extraction from U-bearing minerals and handling may cause a leakage of heavily toxic radioactive pollution, which ends up in water bodies and soil. Therefore, tackling U-contaminated water is crucial to preserve water integrity and quality. Zeolites are known as profound ion exchangers with great affinity towards cationic species present in polluted waters. Various zeolite synthesis routes have made this group of aluminosilicates even more promising to be applied as water purification materials. Here, the synthetic gismondite, faujasite, and Linde type-A zeolites from coal fly-ash were synthesized via tailored, coupled fusion-hydrothermal method and applied to remove aqueous uranium (primarily as 238U) under varying pH, time (sorption kinetics), and initial U concentrations (sorption isotherms). The maximum U uptake was observed for Na–P1 (GIS) zeolite, which equals 48.72 mg U/g, the highest reported value on maximum U adsorption capacity for zeolitic materials. The U adsorption kinetics showed that equilibrium is reached after approximately 3 h of adsorption and that the removal process follows a Freundlich isothermal model for all zeolites, thus preferential adsorption onto heterogeneous surfaces. Advanced spectroscopic studies, including laboratory-scale X-ray Photoelectron Spectroscopy with synchrotron light X-ray Absorption Near Edge Structure in High Energy Resolution Fluorescence Detection mode, revealed that at acidic pH, predominantly an ion exchange between Na+ ions with hexavalent uranyl species takes place. In contrast, in the neutral pH region, the U is immobilized via precipitation in the form of μm-scale mineral aggregates of Na-schoepite: Na[(UO2)4O2(OH)5](H2O)5↓. The outcomes of the research study has demonstrated that synthetic zeolites, obtained from industrial by-products such as coal fly-ash, can be successfully valorized to efficient U adsorbents while unveiling the insights to understand the zeolites/U interactions at the nanoscale level.

Customizing the luminescent properties of compositionally disordered ceramics (Gd, Y, Yb, Tb, Ce)3Al2Ga3O12: From an ultra-fast scintillator to bright, wide-spectrum phosphor

A series of (Gd, Y, Yb, Tb, Ce)3Al2Ga3O12 compositionally disordered compounds with a garnet structure were prepared in the form of ceramics by sintering in oxygen at 1650 °C for 2 h and studied for the luminescent properties and interaction of ions entering the matrix host. The luminescence features of Ce3+ ions were found to be strongly dependent on the Yb concentration. Photoluminescence and scintillation kinetics are characterized by subnanosecond kinetics when the Yb index in the compound exceeds X = 0.3. It opens an opportunity to create an extremely fast and dense scintillation material emitting in a visible range. A further decrease in the Yb index in the compound leads to an increase in the intensity of Yb3+ infrared (IR) emission, whereas Ce3+ and Tb3+ ions contribute to the luminosity of the material by overlapping intra- and intereconfiguration luminescence bands in the spectral range of 300–700 nm. This finding opens an opportunity to create converter materials tolerant to the corpuscular radiation of isotope sources, providing a high efficiency of electric current production when coupled with a silicon photovoltaic element. The compounds were engineered at the nanoscale level, providing control over electronic excitation transfer between luminescent ions.

Review on Nanotechnology in Cosmetics and Dermatology

Nanotechnology is a cutting-edge technology that involves the manipulation of atoms and molecules on a microscopic scale. The cosmetic industry was the first to embrace this technology in their product development, and it has since become one of the most widely-used and capable technologies of the 21st century. It is a safe and effective method for creating innovative drug delivery systems. Nanomaterials, which contain active substances, carriers, and aids, are used in the development of haircare, oral care, and dermatological products that aim to enhance the user’s appearance. The cosmetic industry uses various types of nanomaterials, such as nanosomes, fullerenes, liposomes, ectosomes, and solid lipid nanoparticles. Due to the superior qualities of atoms at the nanoscale level, nanotechnology is increasingly being utilized in the fields of cosmetics and dermatology. Overall, nanotechnology is an excellent option for improving the quality of cosmetic products. Its effectiveness and safety have been proven, making it an indispensable tool in modern product development.

Analyzing the Effect of Magnetic Drag Force on Carbon Nanotubes Suspended in Casson Fluid Within Parallel Surfaces with Heat Diffusion and Rate of Molar Reaction: An Analytical Approach

The study of hydromagnetic CNTs of Casson fluids in Poiseuille flow has significant implications for various industries and can provide valuable insights into the fundamental properties, such as viscosity and conductivity of these fluids. They can improve the heat transfer properties of fluids and enhance the overall efficiency of thermal systems and the presence of CNTs can induce a magnetic field in the fluid. The main goal of using carbon nanotubes (CNTs) in Poiseuille flow is to enhance the fluid flow properties, such as viscosity, thermal conductivity, and heat transfer and the novelty of CNTs in Poiseuille flow lies in their ability to modify the fluid flow properties by altering the structure of the fluid at the nanoscale level. The use of CNTs in Poiseuille flow has gained attention due to their unique mechanical, electrical, and thermal properties. An analytical approach to the investigation of heat transmission in hydro-magnetic forces of natural convective flow of Casson-fluid in a Poiseuille flow implanted by Darcian regime on Carbon Nanotubes with the impacts of magnetic field, heat generation, diffusion thermo, porosity, radiation and first order chemical reaction is presented. In this research, dual solutions are introduced for single-wall and multiple-wall carbon nanotubes over velocity and temperature of nanofluid by the application of various physical and they are elaborated via plane curves. The base fluid is considered for the CNTs as Engine oil. Validity of this model has established by comparing with the available previous literature and is found acceptable agreement with it. In the present study, it is found that the fluctuation in radiation and heat generation plays a significant role in CNTs. It is known that a rise in the Casson parameter and nanoparticle volume fraction enhances the fluid velocity. It is concluded that, the volume fraction of nanoparticles in Poiseuille flow can have a significant impact on the flow behaviour and properties of the fluid. This study has tremendous feasible applications in the areas related to biomedical sciences, water purification process, technology of fibers, nano-materials technology, storage of energy and various applications.

Integrating run-to-run control with feedback control for a spatial atomic layer etching reactor

Semiconductor manufacturing employs an intricate framework of processes that require accurate design specifications at the nanoscale level. Thermal atomic layer etching fulfills these stringent criteria in an exemplary manner by conducting top-down removal of transistor films to further downsize thicknesses and facilitate transistor densification on wafers. However, it has low productivity. Thus, a spatial sheet-to-sheet reactor is appropriate for achieving high throughput while maintaining substrate quality. In order to continuously regulate the process, a run-to-run (R2R) controller coupled with a continuous feedback proportional–integral (PI) controller is proposed to mitigate a kinetic shift disturbance and a continuous pressure ramp disturbance through a multivariate input correction procedure. A tuning methodology is employed to determine the optimal tuning parameters to enhance the performance of the R2R and PI controller response to their respective disturbances. Results indicate that the combined R2R and PI controller outperforms the sole R2R controller by minimizing the amount of input correction needed to minimize the etching per cycle offset from the setpoint.

Tracing the slow Arrhenius process deep in the glassy state-quantitative evaluation of the dielectric relaxation of bulk samples and thin polymer films in the temperature domain.

The slow Arrhenius process (SAP) is a dielectric mode connected to thermally activated equilibration mechanisms, allowing for a fast reduction in free energy in liquids and glasses. The SAP, however, is still poorly understood, and so far, this process has mainly been investigated at temperatures above the glass transition. By employing a combination of methods to analyze dielectric measurements under both isochronal and isothermal conditions, we were able to quantitatively reproduce the dielectric response of the SAP of different polymers and to expand the experimental regime over which this process can be observed down to lower temperatures, up to 70K below the glass transition. Employing thin films of thicknesses varying between 10 and 800nm, we further verified that the peak shape and activation energy of the SAP of poly(4-bromostyrene) are not sensitive to temperature, nor do they vary upon confinement at the nanoscale level. These observations confirm the preliminary trends reported for other polymers. We find that one single set of parameters-meaning the activation barrier and the pre-exponential factor, respectively, linked to the enthalpic and entropic components of the process-can describe the dynamics of the SAP in both the supercooled liquid and glassy states, in bulk and thin films. These results are discussed in terms of possible molecular origins of the slow Arrhenius process in polymers.

Multiscale observations on mechanisms for direct regeneration of degraded NCM cathode materials

The direct regeneration of degraded cathode materials in spent lithium-ion batteries (LIBs) is an environmentally sustainable and cost-effective strategy to “make waste be wealth”. However, the microscopic regeneration mechanisms and kinetics for this process are almost elusive. In this paper, we attempt to fully extract the regeneration mechanisms during direct regeneration of degraded NCM 523 (LiNi0.5Co0.2Mn0.3O2) materials in a multiscale manner. A series of in situ (TEM, SEM, synchrotron XPS) and ex situ (TEM & EDS tomography, electrochemical measurements) characterization techniques are used for establishing the complete physicochemical picture of NCM 523 regeneration. Important dynamical details across atomic-scale, nanoscale, microscale, and single-particle level including reverse transformation from rock salt to layered phase, healing of defects (pores and cracks), and valence transformations of metal ions are followed and discussed, which is further supplemented by systematical theoretical analysis as well as full-cell electrochemical tests. This study provides an in-depth understanding toward the direct regeneration of degraded cathode materials and may shed light on the future development and optimization of direct regeneration strategies.

Effects of various types of organo-mica on the physical properties of polyimide nanocomposites

Poly(amic acid) (PAA) was synthesized using dianhydride 4,4’-oxydiphthalic anhydride and diamine 3,3'-dihydroxybenzidine, and polyimide (PI) hybrid films were synthesized by dispersing organo-mica in PAA through a solution intercalation method. Hexadimethrine-mica (HM-Mica), 1,2-dimethylhexadecylimidazolium-mica (MI-Mica), and didodecyldiphenylammonium-mica (DP-Mica), which were obtained via the organic modification of pristine mica, were used as the organo-micas for the PI hybrid films. The organo-mica content was varied from 0.5 to 3.0 wt% with respect to the PI matrix. The thermomechanical properties, morphology, and optical transparency of the resultant PI hybrid films were measured and compared. Dispersion of even small amounts of organo-mica effectively improved the physical properties of the PI hybrids, and maximum enhancements in physical properties were observed at a specific critical content. Electron microscopy of the hybrid films revealed that the organo-mica uniformly dispersed throughout the polymer matrix at the nanoscale level when added at low contents but aggregated in the matrix when added at levels above the critical content. Structural changes in the organo-mica closely influenced the changes in the physical properties of the hybrid films. All PI hybrid films with various organo-mica contents showed similar optical properties, but that prepared with MI-Mica demonstrated the best thermomechanical properties. All synthesized PI hybrid films were transparent regardless of the type and content of organo-mica used.

Atomic Force Microscopy in the Characterization of the Structure of Cell Wall Components.

Atomic force microscopy (AFM) has broken boundaries in the characterization of the supramolecular architecture of cell wall assemblies and single cell wall polysaccharides at the nanoscale level. Moreover, AFM provides an opportunity to evaluate the mechanical properties of cell wall material which is not possible with any other method. However, in the case of plant tissue, the critical step is a smart sample preparation that should not affect the polysaccharide structure or assembly and on the other hand should consider device limitations, especially scanner ranges. In this chapter, the protocols from the sample preparation, including isolation of cell wall material and extraction of cell wall polysaccharide fractions, through AFM imaging of polysaccharide assemblies and single molecules until an image analysis to obtain quantitative data characterizing the biopolymers are presented.

Individualized high-resolution analysis to categorize diverse learning and memory deficits in tau rTg4510 mice exposed to low-intensity blast.

Mild traumatic brain injury (mTBI) resulting from low-intensity blast (LIB) exposure in military and civilian individuals is linked to enduring behavioral and cognitive abnormalities. These injuries can serve as confounding risk factors for the development of neurodegenerative disorders, including Alzheimer's disease-related dementias (ADRD). Recent animal studies have demonstrated LIB-induced brain damage at the molecular and nanoscale levels. Nevertheless, the mechanisms linking these damages to cognitive abnormalities are unresolved. Challenges preventing the translation of preclinical studies into meaningful findings in "real-world clinics" encompass the heterogeneity observed between different species and strains, variable time durations of the tests, quantification of dosing effects and differing approaches to data analysis. Moreover, while behavioral tests in most pre-clinical studies are conducted at the group level, clinical tests are predominantly assessed on an individual basis. In this investigation, we advanced a high-resolution and sensitive method utilizing the CognitionWall test system and applying reversal learning data to the Boltzmann fitting curves. A flow chart was developed that enable categorizing individual mouse to different levels of learning deficits and patterns. In this study, rTg4510 mice, which represent a neuropathology model due to elevated levels of tau P301L, together with the non-carrier genotype were exposed to LIB. Results revealed distinct and intricate patterns of learning deficits and patterns within each group and in relation to blast exposure. With the current findings, it is possible to establish connections between mice with specific cognitive deficits to molecular changes. This approach can enhance the translational value of preclinical findings and also allow for future development of a precision clinical treatment plan for ameliorating neurologic damage of individuals with mTBI.

Customizing precise, tunable, and universal cascade charge transfer chains towards versatile photoredox catalysis.

The core factors dictating the photocatalysis efficiency are predominantly centered on controllable modulation of anisotropic spatial charge transfer/separation and regulating vectorial charge transport pathways. Nonetheless, the sluggish charge transport kinetics and incapacity of precisely tuning interfacial charge flow at the nanoscale level are still the primary dilemma. Herein, we conceptually demonstrate the elaborate design of a cascade charge transport chain over transition metal chalcogenide-insulating polymer-cocatalyst (TIC) photosystems via a progressive self-assembly strategy. The intermediate ultrathin non-conjugated insulating polymer layer, i.e., poly(diallyl-dimethylammonium chloride) (PDDA), functions as the interfacial electron relay medium, and simultaneously, outermost co-catalysts serve as the terminal "electron reservoirs", synergistically contributing to the charge transport cascade pathway and substantially boosting the interfacial charge separation. We found that the insulating polymer mediated unidirectional charge transfer cascade is universal for a large variety of metal or non-metal reducing co-catalysts (Au, Ag, Pt, Ni, Co, Cu, NiSe2, CoSe2, and CuSe). More intriguingly, such peculiar charge flow characteristics endow the self-assembled TIC photosystems with versatile visible-light-driven photoredox catalysis towards photocatalytic hydrogen generation, anaerobic selective organic transformation, and CO2-to-fuel conversion. Our work would provide new inspiration for smartly mediating spatial vectorial charge transport towards emerging solar energy conversion.

Well-defined tricobalt tetraoxide's critical morphology effect on the structure-reactivity relationship.

This review focuses on exploring the intricate relationship between the catalyst particle size and shape on a nanoscale level and how it affects the performance of reactions. Drawing from decades of research, valuable insights have been gained. Intentionally shaping catalyst particles makes exposing a more significant percentage of reactive facets possible, enabling the control of overactive sites. In this study, the effectiveness of Co3O4 nanoparticles (NPs) with nanometric size as a catalyst is examined, with a particular emphasis on the coordination patterns between oxygen and cobalt atoms on the surface of these NPs. Investigating the correlation between the structure and reactivity of the exposed NPs reveals that the form of Co3O4 with nanometric size can be modified to tune its catalytic capabilities finely. Morphology-dependent nanocatalysis is often attributed to the advantageous exposure of reactive crystal facets accumulating numerous active sites. However, experimental evidences highlight the importance of considering the reorganization of NPs throughout their actions and the potential synergistic effects between nearby reactive and less-active aspects. Despite the significant role played by the atomic structure of Co3O4 NPs with nanometric size, limited attention has been given to this aspect due to challenges in high-resolution characterizations. To bridge this gap, this review strongly advocates for a comprehensive understanding of the relationship between the structure and reactivity through real-time observation of individual NPs during the operation. Proposed techniques enable the assessment of dimensions, configuration, and interfacial arrangement, along with the monitoring of structural alterations caused by fluctuating temperature and gaseous conditions. Integrating this live data with spectroscopic methods commonly employed in studying inactive catalysts holds the potential for an enhanced understanding of the fundamental active sites and the dynamic behavior exhibited in catalytic settings.

Analysing micro- and nanoplastics with cutting-edge infrared spectroscopy techniques: a critical review.

The escalating prominence of micro- and nanoplastics (MNPs) as emerging anthropogenic pollutants has sparked widespread scientific and public interest. These minuscule particles pervade the global environment, permeating drinking water and food sources, prompting concerns regarding their environmental impacts and potential risks to human health. In recent years, the field of MNP research has witnessed the development and application of cutting-edge infrared (IR) spectroscopic instruments. This review focuses on the recent application of advanced IR spectroscopic techniques and relevant instrumentation to analyse MNPs. A comprehensive literature search was conducted, encompassing articles published within the past three years. The findings revealed that Fourier transform infrared (FTIR) spectroscopy stands as the most used technique, with focal plane array FTIR (FPA-FTIR) representing the cutting edge in FTIR spectroscopy. The second most popular technique is quantum cascade laser infrared (QCL-IR) spectroscopy, which has facilitated rapid analysis of plastic particles. Following closely is optical photothermal infrared (O-PTIR) spectroscopy, which can furnish submicron spatial resolution. Subsequently, there is atomic force microscopy-based infrared (AFM-IR) spectroscopy, which has made it feasible to analyse MNPs at the nanoscale level. The most advanced IR instruments identified in articles covered in this review were compared. Comparison metrics encompass substrates/filters, data quality, spatial resolution, data acquisition speed, data processing and cost. The limitations of these IR instruments were identified, and recommendations to address these limitations were proposed. The findings of this review offer valuable guidance to MNP researchers in selecting suitable instrumentation for their research experiments, thereby facilitating advancements in research aimed at enhancing our understanding of the environmental and human health risks associated with MNPs.

Colocalising proteins and polysaccharides in plants for cell wall and trafficking studies.

Plant cell walls (PCWs) are intricate structures with complex polysaccharides delivered by distinct trafficking routes. Unravelling the intricate trafficking pathways of polysaccharides and proteins involved in PCW biosynthesis is a crucial first step towards understanding the complexities of plant growth and development. This study investigated the feasibility of employing a multi-modal approach that combines transmission electron microscopy (TEM) with molecular-genetic tagging and antibody labelling techniques to differentiate these pathways at the nanoscale. The genetically encoded electron microscopy (EM) tag APEX2 was fused to Arabidopsis thaliana cellulose synthase 6 (AtCESA6) and Nicotiana alata ARABINAN DEFICIENT LIKE 1 (NaARADL1), and these were transiently expressed in Nicotiana benthamiana leaves. APEX2 localization was then combined with immunolabeling using pectin-specific antibodies (JIM5 and JIM7). Our results demonstrate distinct trafficking patterns for AtCESA6 and NaARADL, with AtCESA6 localized primarily to the plasma membrane and vesicles, while NaARADL1 was found in the trans-Golgi network and cytoplasmic vesicles. Pectin epitopes were observed near the plasma membrane, in Golgi-associated vesicles, and in secretory vesicle clusters (SVCs) with both APEX2 constructs. Notably, JIM7 labelling was found in vesicles adjacent to APEX2-AtCESA6 vesicles, suggesting potential co-trafficking. This integrative approach offers a powerful tool for elucidating the dynamic interactions between PCW components at the nanoscale level. The methodology presented here facilitates the precise mapping of protein and polysaccharide trafficking pathways, advancing our understanding of PCW biosynthesis and providing avenues for future research aimed at engineering plant cell walls for various applications.

The existence of a strongly bonded layer in associating liquids within silica pores - a spectral and molecular dynamics study.

The properties of confined materials are assumed to be governed by the phenomena occurring at the interface, especially the formation of an irreversible adsorption layer (IAL), which has been widely discussed and detected in the case of thin polymer films and silica nanoparticles. In this paper, we present a novel experimental approach allowing us to reveal the formation of an IAL in two phenyl alcohols infiltrated into various mesoporous silica templates. The proposed methodology (based on evaporation) allowed us to detect the alterations in the OH and aromatic CH stretching vibration bands in infrared spectra, which were considered as evidence of the existence of IAL in constrained systems. Such interpretation was also confirmed by complementary molecular dynamics (MD) simulations that indicated the creation of much stronger hydrogen bonds between alcohols and silanol units than between alcohols themselves. Moreover, computation allowed us to identify additional enormously strong π-stacking interactions between phenyl rings stabilizing the interfacial layer. MD simulations also shed new light on the clustering process of both alcohols under confinement. Simulation and experimental data presented in this paper allowed a much deeper understanding of the processes occurring at the interface-formation of IAL and the association phenomenon at the nanoscale level.

Large-area grown ultrathin molybdenum oxides for label-free sensitive biomarker detection.

The rise of two-dimensional (2D) materials has provided a confined geometry and yielded methods for guiding electrons at the nanoscale level. 2D material-enabled electronic devices can interact and transduce the subtle charge perturbation and permit significant advancement in molecule discrimination technology with high accuracy, sensitivity, and specificity, leaving a significant impact on disease diagnosis and health monitoring. However, high-performance biosensors with scalable fabrication ability and simple protocols have yet to be fully realized due to the challenges in wafer-scale 2D film synthesis and integration with electronics. Here, we propose a molybdenum oxide (MoOx)-interdigitated electrode (IDE)-based label-free biosensing chip, which stands out for its wafer-scale dimension, tunability, ease of integration and compatibility with the complementary metal-oxide-semiconductor (CMOS) fabrication. The device surface is biofunctionalized with monoclonal anti-carcinoembryonic antigen antibodies (anti-CEA) via the linkage agent (3-aminopropyl)triethoxysilane (APTES) for carcinoembryonic antigen (CEA) detection and is characterized step-by-step to reveal the working mechanism. A wide range and real-time response of the CEA concentration from 0.1 to 100 ng mL-1 and a low limit of detection (LOD) of 0.015 ng mL-1 were achieved, meeting the clinical requirements for cancer diagnosis and prognosis in serum. The MoOx-IDE biosensor also demonstrates strong surface affinity towards molecules and high selectivity using L-cysteine (L-Cys), glycine (Gly), glucose (Glu), bovine serum albumin (BSA), and immunoglobulin G (IgG). This study showcases a simple, scalable, and low-cost strategy to create a nanoelectronic biosensing platform to achieve high-performance cancer biomarker discrimination capabilities.

Metals in nanomotion: probing the role of extracellular vesicles in intercellular metal transfer.

Metals in living organisms and environments are essential for key biological functions such as enzymatic activity, and DNA and RNA synthesis. This means that disruption of metal ion homeostasis and exchange between cells can lead to diseases. EVs are believed to play an essential role in transporting metals between cells, but the mechanism of metal packaging and exchange remains to be elucidated. Here, we established the elemental composition of EVs at the nanoscale and single-vesicle level and showed that the metal content depends on the cell type and culture microenvironment. We also demonstrated that EVs participate in the exchange of metal elements between cells. Specifically, we used two classes of EVs derived from papaya fermented fluid (PaEVs), and decidual mesenchymal stem/stromal cells (DEVs). To show that EVs transfer metal elements to cells, we treated human osteoblast-like cells (MG63) and bone marrow mesenchymal stem cells (BMMSCs) with both classes of EVs. We found that both classes of EVs contained various metal elements, such as Ca, P, Mg, Fe, Na, Zn, and K, originating from their parent cells, but their relative concentrations did not mirror the ones found in the parent cells. Single-particle analysis of P, Ca, and Fe in DEVs and PaEVs revealed varying element masses. Assuming spherical geometry, the mean mass of P was converted to a mean size of 62 nm in DEVs and 24 nm in PaEVs, while the mean sizes of Ca and Fe in DEVs were smaller, converting to 20 nm and 30 nm respectively. When EVs interacted with BMMSCs and MG63, DEVs increased Ca, P, and Fe concentrations in BMMSCs and increased Fe concentration in MG63, while PaEVs increased Ca concentrations in BMMSCs and had no effect on MG63. The EV cargo, including proteins, nucleic acids, and lipids, differs from their origin in composition, and this variation extends to the element composition of EVs in our study. This fundamental understanding of EV-mediated metal exchange between cells could offer a new way of assessing EV functionality by measuring their elemental composition. Additionally, it will contribute novel insights into the mechanisms underlying EV production and their biological activity.

Surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS) in label-free characterization of erythrocyte membranes and extracellular vesicles at the nano-scale and molecular level.

The manuscript presents the potential of surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS) for label-free characterization of extracellular microvesicles (EVs) and their isolated membranes derived from red blood cells (RBCs) at the nanoscale and at the single-molecule level, providing detection of a few individual amino acids, protein and lipid membrane compartments. The study shows future directions for research, such as investigating the use of the mentioned techniques for the detection and diagnosis of diseases. We demonstrate that SERS and TERS are powerful techniques for identifying the biochemical composition of EVs and their membranes, allowing the detection of small molecules, lipids, and proteins. Furthermore, extracellular vesicles released from red blood cells (REVs) can be broadly classified into exosomes, microvesicles, and apoptotic bodies, based on their size and biogenesis pathways. Our study specifically focuses on microvesicles that range from 100 to 1000 nanometres in diameter, as presented in AFM images. Using SERS and TERS spectra obtained for REVs and their membranes, we were able to characterize the chemical and structural properties of microvesicle membranes with high sensitivity and specificity. This information may help better distinguish and categorize different types of EVs, leading to a better understanding of their functions and potential biomedical applications.