Metal Oxide Nanomaterials Research Articles

Comparative Surface Interaction Study to Detect Brucella melitensis 16M Using Biosensor Transducer Modifications with 4-MBA, ZnONPs/AuNPs, ZnONPs/AuNPs/4-MBA

Brucellosis is a zoonotic disease endemic in developing countries and caused by gram-negative bacteria of genus Brucella infecting both livestock and humans. Brucella melitensis and Brucella abortus are important species representing largest biotypes world-wide. Therefore, modified detection strategies and advancement in potential analytical tools are required to monitor its rapid prevalence. In this study, we aim to modify gold-transducer of Surface Plasmon Resonance biosensor with combination of metal oxide nanomaterials and chemical probe to detect recombinant outer membrane ‘rOmp28’ protein antigen of Brucella melitensis 16M in concentration-dependent surface interactions. We synthesized Zinc (ZnONPs) and Gold (AuNPs) nanoparticles using standard ‘Hydrothermal and Turkevich Methods’ and their crystalline structure, chemical property and morphology were analysed using UV-Visible Spectrophotometry, FT-IR, Powder-XRD, SEM-EDX and TEM-SAED. For immobilizing specific rOmp28 derived IgG-pAbs on modified Au-transducer, rOmp28 protein was expressed and purified using Ni-NTA gel affinity chromatography for producing pAbs in BALB/c mice. Three modifications of Au-transducer with 4-MBA, ZnONPs/AuNPs and ZnONPs/AuNPs/4-MBA were subjected for immobilization and SPR biosensing was performed with rOmp28 Ag at detection range of 0.1 μg mL-1 to 0.01 fg mL-1. Limit of detection observed with ZnONPs/AuNPs/4-MBA combination was 0.1 fg mL-1 by relative increase in SPR response angle at 0.1 μg mL-1 in the order 83.7° < 98.9° < 179.2° for 4-MBA < ZnONPs/AuNPs < ZnONPs/AuNPs/4-MBA respectively. In conclusion, metal oxide nanomaterials in combination with biosensor are suitable in sensitive and specific interaction of antigen displaying lowest LODs and enhanced biosensor response for on-field real-time Brucella detection in both clinical and non-clinical disease scenario.

Impact of calcination temperature on structural and electrical behaviour of Fe3+/Fe2+ modified Zinc oxide nanostructures

Metal oxide nanomaterials are very popular due to its extensive band gap with significant applications in photovoltaic, catalysis, sensors, actuators and many more. This work on the impact of Fe3+ ion substitution on structural and electronic transportation character of ZnO nano structures prepared through co-precipitation method. The prepared samples were characterized via XRD, Field Emission Scanning Electron Microscope, FT-IR (Infrared Spectroscopy), PL (Photo-luminescence) and Complex Impedance Spectroscopy. From the XRD data, the wurtzite hexagonal structure in space group P63mc was demonstrated. The calculated crystallite sizes, planner distance and cell volume of Fe/ZnO-300 nanoparticles is 28.6 nm, 2.6012 Å and 59.41 Å3. The micrograph of Morphologies reveals the agglomeration in samples. The PL spectrum traced via PL spectrometer with 320 nm excitation wavelength (λ). IR spectrums with acmes close to 529–634 cm−1 were traced via FTIR technique and ensuing to stretching in the Zn-O bond. The impedance spectroscopies of La/ZnO-300 nanoparticles were measured via impedance Analyzer in the frequency assortment 5 MHz to 10 Hz at room temperature (RT). The value of grain margin resistance is 26.10 MΩ (at 300 K or RT) with the dielectric constant value 370 for La/ZnO-300 samples.

Electrochemical Nanosensors for Sensitization of Sweat Metabolites: From Concept Mapping to Personalized Health Monitoring.

Sweat contains a broad range of important biomarkers, which may be beneficial for acquiring non-invasive biochemical information on human health status. Therefore, highly selective and sensitive electrochemical nanosensors for the non-invasive detection of sweat metabolites have turned into a flourishing contender in the frontier of disease diagnosis. A large surface area, excellent electrocatalytic behavior and conductive properties make nanomaterials promising sensor materials for target-specific detection. Carbon-based nanomaterials (e.g., CNT, carbon quantum dots, and graphene), noble metals (e.g., Au and Pt), and metal oxide nanomaterials (e.g., ZnO, MnO2, and NiO) are widely used for modifying the working electrodes of electrochemical sensors, which may then be further functionalized with requisite enzymes for targeted detection. In the present review, recent developments (2018-2022) of electrochemical nanosensors by both enzymatic as well as non-enzymatic sensors for the effectual detection of sweat metabolites (e.g., glucose, ascorbic acid, lactate, urea/uric acid, ethanol and drug metabolites) have been comprehensively reviewed. Along with this, electrochemical sensing principles, including potentiometry, amperometry, CV, DPV, SWV and EIS have been briefly presented in the present review for a conceptual understanding of the sensing mechanisms. The detection thresholds (in the range of mM-nM), sensitivities, linear dynamic ranges and sensing modalities have also been properly addressed for a systematic understanding of the judicious design of more effective sensors. One step ahead, in the present review, current trends of flexible wearable electrochemical sensors in the form of eyeglasses, tattoos, gloves, patches, headbands, wrist bands, etc., have also been briefly summarized, which are beneficial for on-body in situ measurement of the targeted sweat metabolites. On-body monitoring of sweat metabolites via wireless data transmission has also been addressed. Finally, the gaps in the ongoing research endeavors, unmet challenges, outlooks and future prospects have also been discussed for the development of advanced non-invasive self-health-care-monitoring devices in the near future.

Using Nanomaterials as Excellent Immobilisation Layer for Biosensor Design.

The endless development in nanotechnology has introduced new vitality in device fabrication including biosensor design for biomedical applications. With outstanding features like suitable biocompatibility, good electrical and thermal conductivity, wide surface area and catalytic activity, nanomaterials have been considered excellent and promising immobilisation candidates for the development of high-impact biosensors after they emerged. Owing to these reasons, the present review deals with the efficient use of nanomaterials as immobilisation candidates for biosensor fabrication. These include the implementation of carbon nanomaterials-graphene and its derivatives, carbon nanotubes, carbon nanoparticles, carbon nanodots-and MXenes, likewise their synergistic impact when merged with metal oxide nanomaterials. Furthermore, we also discuss the origin of the synthesis of some nanomaterials, the challenges associated with the use of those nanomaterials and the chemistry behind their incorporation with other materials for biosensor design. The last section covers the prospects for the development and application of the highlighted nanomaterials.

Heterometallic 3d–4f Alkoxide Precursors for the Synthesis of Binary Oxide Nanomaterials

In this study, a new method for the synthesis of heterometallic 3d-4f alkoxides by the direct reaction of metallic lanthanides (La, Pr, Nd, Gd) with MCl2 (M = Mn, Ni, Co) in 2-methoxyethanol was developed. The method was applied to the synthesis of the heterometallic oxo-alkoxide clusters [Ln4Mn2(μ6-O)(μ3-OR)8(HOR)xCl6] (Ln = La (1), Nd (2), Gd (3); x = 0, 2, 4); [Pr4M2(μ6-O)(μ3-OR)8(HOR)xCl6] (M = Co (4), Ni (5); x = 2, 4); and [Ln4Mn2(μ3-OH)2(μ3-OR)4(μ-OR)4(μ-Cl)2(HOR)4Cl6] (Ln = La (11) and Pr (12)). Mechanistic investigation led to the isolation of the homo- and heterometallic intermediates [Pr(μ-OR)(μ-Cl)(HOR)Cl]n (6), [Co4(μ3-OR)4(HOR)4Cl4] (7), [Ni4(μ3-OR)4(HOEt)4Cl4] (8), [Mn4(μ3-OR)4(HOR)2(HOEt)2Cl4] (9), and [Nd(HOR)4Cl][CoCl4] (10). In the presence of an external M(II) source at 1100 °C, 1-4 and 12 were selectively converted into binary metal oxide nanomaterials with trigonal or orthorhombic perovskite structures, i.e., LaMnO3, GdMnO3, NdMnO3, Pr0.9MnO3, and PrCoO3. Compound 5 decomposed into a mixture of homo- and heterometallic oxides. The method presented provides a valuable platform for the preparation of advanced heterometallic oxide materials with promising magnetic, luminescence, and/or catalytic applications.

Poly-thymine DNA templated MnO2 biomineralization as a high-affinity anchoring enabling tumor targeting delivery

Manganese oxide nanomaterials (MONs) are emerging as a type of highly promising nanomaterials for diseases diagnosis, and surface modification is the basis for colloidal stability and targeting delivery of the nanomaterials. Here, we report the in-situ functionalization of MnO2 with DNA through a biomineralization process. Using adsorption-oxidation method, DNA templated Mn2+ precursor to biomineralize into nano-cubic seed, followed by the growth of MnO2 to form cube/nanosheet hybrid nanostructure. Among four types of DNA homopolymers, poly-thymine (poly-T) was found to stably attach on MnO2 surface to resist various biological displacements (phosphate, serum, and complementary DNA). Capitalized on this finding, a di-block DNA was rationally designed, in which the poly-T block stably anchored on MnO2 surface, while the AS1411 aptamer block was not only an active ligand for tumor targeting delivery, but also a carrier for photosensitizer (Ce6) loading. Upon targeting delivery into tumor cells, the MnO2 acted as catalase-mimic nanozyme for oxygenation to sensitize photodynamic therapy, and the released Mn2+ triggered chemodynamic therapy via Fenton-like reaction, achieving synergistic anti-tumor effect with full biocompatibility. This work provides a simple yet robust strategy to functionalize metal oxides nanomaterials for biological applications via DNA-templated biomineralization.

Acute phase response following pulmonary exposure to soluble and insoluble metal oxide nanomaterials in mice

BackgroundAcute phase response (APR) is characterized by a change in concentration of different proteins, including C-reactive protein and serum amyloid A (SAA) that can be linked to both exposure to metal oxide nanomaterials and risk of cardiovascular diseases. In this study, we intratracheally exposed mice to ZnO, CuO, Al2O3, SnO2 and TiO2 and carbon black (Printex 90) nanomaterials with a wide range in phagolysosomal solubility. We subsequently assessed neutrophil numbers, protein and lactate dehydrogenase activity in bronchoalveolar lavage fluid, Saa3 and Saa1 mRNA levels in lung and liver tissue, respectively, and SAA3 and SAA1/2 in plasma. Endpoints were analyzed 1 and 28 days after exposure, including histopathology of lung and liver tissues.ResultsAll nanomaterials induced pulmonary inflammation after 1 day, and exposure to ZnO, CuO, SnO2, TiO2 and Printex 90 increased Saa3 mRNA levels in lungs and Saa1 mRNA levels in liver. Additionally, CuO, SnO2, TiO2 and Printex 90 increased plasma levels of SAA3 and SAA1/2. Acute phase response was predicted by deposited surface area for insoluble metal oxides, 1 and 28 days post-exposure.ConclusionSoluble and insoluble metal oxides induced dose-dependent APR with different time dependency. Neutrophil influx, Saa3 mRNA levels in lung tissue and plasma SAA3 levels correlated across all studied nanomaterials, suggesting that these endpoints can be used as biomarkers of acute phase response and cardiovascular disease risk following exposure to soluble and insoluble particles.

Surfactant-free synthesis of metal and metal oxide nanomaterials: a perspective

Recent developments pertaining to the surfactant-free synthesis of metal and metal oxide nanomaterials are deliberated, with a focus on important challenges, opportunities, and future perspectives.

Probing size-dependent defects in zinc oxide using synchrotron techniques: impact on photocatalytic efficiency.

In the present study, synchrotron-based X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS) and X-ray excited optical luminescence (XEOL) have been used to investigate the induced defect states in metal oxide nanomaterials. Specifically, two synthesis approaches have been followed to develop unique nano-sized peanut-shaped (N-ZnO) nanostructures and micron-sized hexagonal rods (M-ZnO). XANES analysis at the Zn K-edge revealed the presence of defect states with a divalent oxidation state of zinc (Zn2+) in a tetrahedral structure. Furthermore, XAS measurements performed at the Zn L3,2-edge and O K-edge confirm higher oxygen-related defects in M-ZnO, while N-ZnO appeared to have a higher concentration of surface defects due to size confinement. Moreover, the in-line XEOL and time dependent-XEOL measurements exposed the radiative excitonic recombination phenomena occurring in the band-tailing region as a function of absorption length, X-ray energy excitation, and time. Based on the chronology developed in the defect state improvement, a possible energy band diagram is proposed to accurately locate the defect states in the two systems. Furthermore, the increased absorption intensity at the Zn L3,2-edge and the O K-edge under the UV lamp suggests delayed recombination of electrons and holes, highlighting their potential use as photo catalysts. The photocatalytic activity degrading the rhodamine B dye established M-ZnO as a superior catalyst with a rapid degradation rate and significant mineralization. Overall, this work provides valuable insights into ZnO defect states and provides a foundation for efficient advanced materials for environmental or other optoelectronic applications.

Immunotoxicity of metal and metal oxide nanoparticles: from toxic mechanisms to metabolism and outcomes.

The influence of metal and metal oxide nanomaterials on various fields since their discovery has been remarkable. They have unique properties, and therefore, have been employed in specific applications, including biomedicine. However, their potential health risks cannot be ignored. Several studies have shown that exposure to metal and metal oxide nanoparticles can lead to immunotoxicity. Different types of metals and metal oxide nanoparticles may have a negative impact on the immune system through various mechanisms, such as inflammation, oxidative stress, autophagy, and apoptosis. As an essential factor in determining the function and fate of immune cells, immunometabolism may also be an essential target for these nanoparticles to exert immunotoxic effects in vivo. In addition, the biodegradation and metabolic outcomes of metal and metal oxide nanoparticles are also important considerations in assessing their immunotoxic effects. Herein, we focus on the cellular mechanism of the immunotoxic effects and toxic effects of different types of metal and metal oxide nanoparticles, as well as the metabolism and outcomes of these nanoparticles in vivo. Also, we discuss the relationship between the possible regulatory effect of nanoparticles on immunometabolism and their immunotoxic effects. Finally, we present perspectives on the future research and development direction of metal and metal oxide nanomaterials to promote scientific research on the health risks of nanomaterials and reduce their adverse effects on human health.

Solid state synthesis, characterization and biological evaluation of silver doped nanosized metal oxides

Nanomaterials have attracted a great deal of attention from the scientific community due to their unique properties and applications. The small size metal oxides have opened up the door for intensive research to utilize their properties for biomedical applications. Silver nanoparticle (AgNPs) and metal oxide nanomaterials like MgO, ZnO, NiO and its silver doped nanocomposites (Ag-MgO, Ag-ZnO, Ag-NiO) have been prepared using solid state combustion method using polyvinyl alcohol (PVA) as a fuel. The structure of as prepared oxides and its silver doped nanocomposites were characterized using X-ray diffraction (XRD) tool and morphology by Scanning Electron Micrograph (SEM) tool as well as Transmission electron micrograph tool respectively. Presence of the metals in the oxides and its Ag composite was confirmed by the EDX pattern. Bonding nature in the composite is well studied by the Fourier transform infrared (FT-IR) tool. Antibacterial activity studies of the nanocomposites are carried out against various bacteria.

Design and Development of Biosensors for Progesterone Detection

Progesterone (P4) is an important biomarker of various diseases. When P4 level exceeds the normal value, the human body produces a series of problems, including carcinogenic risks. Developing the method for P4 monitoring with accurate, inexpensive, and fast becomes an important topic for researchers. In recent years, the abundance of new materials and synthesis technologies has developed P4 biosensors. Based on functional materials, this paper reviews the recent decade literatures and summarizes the latest progress and applications in enhancing detection of P4. In this study, the functional materials used to manufacture P4 biosensors are mainly divided into three categories: metal and metal‐oxide nanomaterials, composite material, and other materials. A composite material refers to a combination of two or three types of materials, including carbonaceous nanomaterials, metal nanomaterials, polymers, and biological materials. The other materials mainly include a combination of special compounds, biomaterials, luciferin materials, and quantum dot materials, of which one or two. The introduction of these new functional materials improves the sensitivity and selectivity of P4 detection. Moreover, this study provides ideas for the future research on improving the performance of P4 biosensor. The future study should put more attentions on enzyme catalysis amplification, cyclic amplification, and DNA isothermal amplification strategies.

A novel method for synthesizing one or two-dimensional metal oxide (hydroxide) nanomaterials using deep eutectic solvents

Metal-based DESs were employed as raw materials and media to fabricate one- or two-dimensional nanomaterials, such as FeO(OH) rod bundle, Co(OH)2nanoplate, ZnO nanorod, and CuO nanoplate.

Chronic exposure to complex metal oxide nanomaterials induces production of reactive oxygen species in bacteria

Chronic exposure of Shewanella oneidensis to nanoscale lithiated nickel manganese cobalt oxide induces ROS production in the bacteria, filamentation, vesicle formation, DNA damage, and evolution of resistance to other stressors such as antibiotics.

A structure-activity approach towards the toxicity assessment of multicomponent metal oxide nanomaterials.

The increase of human and environmental exposure to engineered nanomaterials (ENMs) due to the emergence of nanotechnology has raised concerns over their safety. The challenging nature of in vivo and in vitro toxicity assessment methods for ENMs, has led to emerging in silico techniques for ENM toxicity assessment, such as structure-activity relationship (SAR) models. Although such approaches have been extensively developed for the case of single-component nanomaterials, the case of multicomponent nanomaterials (MCNMs) has not been thoroughly addressed. In this paper, we present a SAR approach for the case metal and metal oxide MCNMs. The developed SAR framework is built using a dataset of 796 individual toxicity measurements for 340 different MCNMs, towards human cells, mammalian cells, and bacteria. The novelty of the approach lies in the multicomponent nature of the nanomaterials, as well as the size, diversity and heterogeneous nature of the dataset used. Furthermore, the approach used to calculate descriptors for surface loaded MCNMs, and the mechanistic insight provided by the model results can assist the understanding of MCNM toxicity. The developed models are able to correctly predict the toxic class of the MCNMs in the heterogeneous dataset, towards a wide range of human cells, mammalian cells and bacteria. Using the abovementioned approach, the principal toxicity pathways and mechanisms are identified, allowing a more holistic understanding of metal oxide MCNM toxicity.

A review on the synthesis of metal oxide nanomaterials by microwave induced solution combustion.

With the increasing awareness of environmental protection and health, the preparation of metal oxide nanomaterials by environmentally friendly methods is favored by more and more researchers both at home and abroad. The preparation of metal oxide nanomaterials by a microwave-induced solution combustion synthesis method can significantly reduce the reaction time, energy consumption, and the use of toxic chemicals, which is an energy-saving, environmentally friendly method for nanomaterials synthesis. In addition, the microwave-induced solution combustion synthesis (MISCS) method has many advantages such as fast reaction speed, high selectivity, small product size, and homogeneous composition. This paper briefly describes the mechanism of the MISCS and its advantages in the synthesis of metal oxide nanomaterials, the related studies on microwave-induced solution combustion synthesis of metal oxide nanomaterials, and the effects of process parameters on the microstructure and properties of metal oxide nanomaterials synthesized by MISCS. Furthermore, some technical difficulties facing the synthesis of metal oxide nanomaterials by MISCS are summarized, and the future direction has also been prospected.

Scope and significance of transition metal oxide nanomaterials for next-generation Li-ion batteries

This article presents a comprehensive overview of the current state-of-the-art research on the use of nanomaterials in batteries and provides valuable insights into their potential applications.

Dextran Sulfate Nanocarriers: Design, Strategies and Biomedical Applications.

Dextran sulfate (DXS) is a hydrophilic, non-toxic, biodegradable, biocompatible and safe biopolymer. These biomedically relevant characteristics make DXS a promising building block in the development of nanocarrier systems for several biomedical applications, including imaging and drug delivery. DXS polyanion can bind with metal oxide nanomaterials, biological receptors and therapeutic drug molecules. By taking advantage of these intriguing properties, DXS is used to functionalize or construct nanocarriers for specific applications. In particular, the diagnostic or therapeutic active agent-loaded DXS nanoparticles are prepared by simple coating, formation of polyelectrolyte complexes with other positively charged polymers or through self-assembly of amphiphilic DXS derivatives. These nanoparticles show a potential to localize the active agents at the pathological site and minimize undesired side effects. As DXS can recognize and be taken up by macrophage surface receptors, it is also used as a targeting ligand for drug delivery. Besides as a nanocarrier scaffold material, DXS has intrinsic therapeutic potential. DXS binds to thrombin, acts as an anticoagulant and exhibits an inhibitory effect against coagulation, retrovirus, scrapie virus and human immunodeficiency virus (HIV). Herein, biomedical applications involving the use of DXS as nanocarriers for drugs, biomolecules, and imaging agents have been reviewed. A special focus has been made on strategies used for loading and delivering of drugs and biomolecules meant for treating several diseases, including cancer, inflammatory diseases and ocular disease.

Enhanced Tribocatalytic Degradation of Organic Pollutants by ZnO Nanoparticles of High Crystallinity

More and more metal oxide nanomaterials are being synthesized and investigated for degradation of organic pollutants through harvesting friction energy, yet the strategy to optimize their performance for this application has not been carefully explored up to date. In this work, three commercially available ZnO powders are selected and compared for tribocatalytic degradation of organic dyes, among which ZnO-1 and ZnO-2 are agglomerates of spherical nanoparticles around 20 nm, and ZnO-3 are particles of high crystallinity with a regular prismatic shape and smooth surfaces, ranging from 50 to 150 nm. Compared with ZnO-1 and ZnO-2, ZnO-3 exhibits a much higher tribocatalytic degradation performance, and a high degradation rate constant of 6.566 × 10-2 min-1 is achieved for RhB, which is superior compared with previous tribocatalytic reports. The stability and universality of ZnO-3 were demonstrated through cycling tests and degradation of different types of dyes. Furthermore, the mechanism of tribocatalysis revealed that h+ was the main active species in the degradation process by ZnO. This work highlights the great significance of high crystallinity rather than a large specific surface area for the development of high-performance tribocatalysts and demonstrates the great potential of tribocatalysis for water remediation.

Metal Oxide Nanomaterials: From Fundamentals to Applications

This Special Issue of Nanomaterials, "Metal Oxide Nanomaterials: From Fundamentals to Applications", highlights the development and understanding of different types of metal oxide nanoparticles and their use for applications in luminescence, photocatalysis, water-oil separation, optoelectronics, gas sensors, energy-saving smart windows, etc [...].