Surface Properties Of Nanomaterials Research Articles

Enhancing electrochemical performance of ultrasmall Fe2O3-embedded carbon nanotubes via combusting-induced high-valence dopants

• Ti 4+ , Sn 4+ , and Zr 4+ were successfully incorporated in Fe 2 O 3 by a flame synthesis. • The Fe 2 O 3 /CNTs nanocomposite was directly obtained by a flame synthesis. • Combustion reaction generating oxygen functional groups favor the wettability of electrode. • High-valence metal ions optimize the electron structure and enhance Na + adsorption. • The flexible Ti-FeO-CNT//MnO 2 achieved an exceeding high operating potential of 2.0 V. Doping is a reasonable solution to improve the electronic structure and surface properties of nanomaterials. Herein, we propose a rapid and simple methodology, flame synthesis, as an effective preparation strategy for incorporating high-valence metal ions (Ti 4+ , Sn 4+ , and Zr 4+ ) into ultrasmall Fe 2 O 3 on carbon nanotube support (i.e., M-FeO-CNT). The resulting materials exhibit not only a boosted Na + adsorption as shown by density functional theory (DFT) calculations, but also display an increased oxygen deficiency. The electrochemical activity and charge transfer efficiency of Fe 2 O 3 can be improved by reasonably substituting Fe 3+ with Ti 4+ , Sn 4+ , and Zr 4+ . The electrochemical investigation of Ti-doped Fe 2 O 3 (Ti-FeO-CNT) electrode demonstrates a splendid specific capacitance of 1.25 F cm −2 at 1 mA cm −2 in 1 M Na 2 SO 4 . This is significantly higher as compared to the capacitance of 0.48 F cm −2 . Flexible solid-state asymmetric supercapacitor Ti-FeO-CNT//MnO 2 is verified with operating voltage of 2.0 V and stability over 3000 cycles, and delivers a high energy density of 2.14 mWh cm −3 at power density of 25 mW cm −3 . The flame synthesis is expected to be widely applicable for the preparation of high-valence metal ions doped nanosized Fe 2 O 3 functionalized materials, thus opening up new avenues for energy and catalysis research.

DNA‐Dependent Prussian Blue Nanoflowers for Biosensing, Catalysis and Imaging

AbstractWhile shapes and surface properties of nanomaterials are known to play important roles in defining their properties, it remains challenging to fine‐tune the morphologies systematically and predictably. Considering the extraordinary performance, prussian blue nanoparticles (PBNPs) are selected as the proof‐of‐concept nanomaterials. Herein, a DNA‐dependence approach to fine‐control the morphology of PBNPs via electrostatic interaction‐mediated self‐assembly of inorganic ions and protonated DNA is developed. The regulation of different DNA on the morphology of PBNPs is systematically investigated. 30‐mer Oligo‐C or ‐T (C30/T30) mediates formation of flower‐like PBNPs (PB nanoflowers), whereas cubic structure with different sizes is observed in the presence of 10‐mer oligo‐G or 30‐mer Oligo‐A (G10/A30). Detailed mechanism studies indicate that the protonation of nucleobases is the key factor for the morphological evolution. C30‐dependent PB nanoflowers are superior to PB nanocubes in photothermal properties, peroxidase mimetic activity, photo‐Fenton catalytic performance, and light scattering property, which present 1.2‐, 3.78‐, 1.58‐, 1.93‐fold improvement, respectively. Furthermore, PB nanoflowers mediated by the diblock DNA (sDNA; comprising C30 and complementary strands of the target DNA) unexpectedly acquire biorecognition capabilities. This study opens a new avenue for the systematic and predictable synthesis of PB nanoflowers, which broadens the repertoire of PBNPs for catalysis, biosensing, and imaging.

Safety assessment of graphene oxide and microcystin-LR complex: a toxicological scenario beyond physical mixture

BackgroundNanomaterials have been widely used in electrochemistry, sensors, medicine among others applications, causing its inevitable environmental exposure. A raising question is the “carrier” effect due to unique surface properties of nanomaterials, which may collectively impact the bioavailability, toxicokinetic, distribution and biological effects of classic toxicants. Noteworthy, this aspect of information remains largely unexplored.MethodsHere, we deliberately selected two entities to mimic this scenario. One is graphene oxide (GO), which is made in ton quantity with huge surface-area that provides hydrophilicity and π–π interaction to certain chemicals of unique structures. The other is Microcystin-LR (MCLR), a representative double-bond rich liver-toxic endotoxin widely distributed in aquatic-system. Firstly, the adsorption of GO and MCLR after meeting under environmental conditions was explored, and then we focused on the toxicological effect and related mechanism of GO-MCLR complex on human skin cutin forming cells (HaCaT cells) and normal liver cells (L02 cells).ResultsAbiotically, our study demonstrated that GO could effectively adsorb MCLR through hydrogen bonding and π–π interaction, the oxidation degree of GO-MCLR decreased significantly and surface defect level raised. Compared to GO or MCLR, GO-MCLR was found to induce more remarkable apoptosis and ferroptosis in both HaCaT and L02 cells. The underlying mechanism was that GO-MCLR induced stronger intracellular reactive oxygen species (ROS) and mtROS generation, followed by Fe2+ accumulation, mitochondrial dysfunction and cytoskeletal damage.ConclusionsThese results suggest that the GO-MCLR complex formed by GO adsorption of MCLR may exhibit more toxic effects than the single material, which demonstrates the necessity for assessing nano-toxicant complexity. Our discovery may serve as a new toxicological paradigm in which nanomaterial mediated surface adsorption effects could impact the degree of cytotoxicity and toxicological mechanisms of classic toxins.Graphical

A systematic review on the effects of nanomaterials on gut microbiota.

Some nanomaterials (NMs) have been shown to possess antimicrobial activity and cause GM dysbiosis. Since NMs are being used widely, a systematic assessment of the effects of NMs on GM is warranted. In this systematic review, a total of 46 in vivo and 22 in vitro studies were retrieved from databases and search engines including Science-Direct, Pubmed and Google scholar. Criteria for assessment of studies included use of in vitro or in vivo studies, characterization of NMs, use of single or multiple doses as well as consistency of results. GM dysbiosis has been studied most widely on TiO2, Ag, Zn-based NMs. There was moderate evidence for GM dysbiosis caused by Zn- and Cu-based NMs, Cu-loaded chitosan NPs and Ag NMs, and anatase TiO2 NPs, as well as low evidence for SWCNTs, nanocellulose, SiO2, Se, nanoplastics, CeO2, MoO3 and graphene-based NMs. Most studies indicate adverse effects of NMs towards GM. However, more work is required to elucidate the differences on the reported effects of NM by type and sex of organisms, size, shape and surface properties of NMs as well as effects of exposure to mixtures of NMs. For consistency and better agreement among studies on GM dysbiosis, there is need for internationally agreed protocols on, inter alia, characterization of NMs, dosing (amounts, frequency and duration), use of sonication, test systems (both in vitro and in vivo), including oxygen levels for in vitro models.

Nanotechnology can Provide Therapeutic Agent by Targeting Molecular Structures of SARS-CoV-2 (COVID-19): A Mini-Review

COVID-19 outbreak has hit the world worst at the start of 2020, as of December 11, 2020, more than 1.5 million people have died and more than 68.8 million people have been infected globally. SARS-CoV-2 induces mild to severe progressive respiratory pneumonia, leading to failure of different body organs and ultimately death. Hitherto, there are no specific and potential therapeutic agents available against the virus. The spike protein is a type I surface glycoprotein facilitating entry of the virus into the host cell via hACE2 receptors. The two subunits of the spike protein have a polybasic link as cleavage site (PRAR) in SARS-CoV-2, with an additional attachment of O-linked glycans. SARS-CoV and SARS-CoV-2 have 76.5% similarity in amino acid sequences. The pathogenesis and viral entry of SARS-CoV-2 are different from SARS-CoV, therefore, it is a dire need of time to develop a target-based treatment. Alternative strategies and multidisciplinary research approaches are crucial for developing new antiviral and improved therapies against COVID-19. Nanotechnology has opened new horizons for evaluating the biological properties and efficacy of different materials having a biological origin, such as Nigella sativa. It contains various active components such as thymoquinone, thymol, thymohydroquinone, and dithymoquinone with different biological potentials. Metallic nanomaterials have been reported to exhibit antiviral activities against various strains. Understanding molecular interactions and modifying the surface properties of nanomaterials with optimum activity may result in the development of novel antiviral therapies.

Photo-Triggered Nanomaterials for Cancer Theranostic Applications

Cancer is one of the most prevalent diseases with mortality rate considerably increasing every year. Conventional treatment strategies for cancer like chemotherapy suffer from the drawbacks of multiple-dose requirements and non-specificity of drug action. Moreover, the cost involved in the diagnosis and treatment is very high. Recently, the application of nanotechnology in the field of cancer has witnessed tremendous significance due to the unique size, shape, and surface properties of nanomaterials. With the intention to utilize biocompatible and biodegradable nanomaterials in cancer and reduce the non-specificity, approaches such as targeted nanotherapeutics came into existence. Besides having therapeutic potential, some materials demonstrate their applicability in bioimaging forecasting distinct optical properties. In this review, we have discussed the basics and principles guiding the design of different photo-triggered nanotheranostic materials used in cancer. Additionally, recent developments and advantages offered by the NIR-responsive photodynamic and photothermal agents along with their future scope have been presented. An overview of the toxicity and clinical prospect of photosensitive agents is also summarized. Overall, the field of photo-triggered cancer nanotheranostics has huge potential that can be clinically translated into an affordable and safe treatment approach.

Nano-bio surface interactions, cellular internalisation in cancer cells and e-data portals of nanomaterials: A review.

Nanomaterials (NMs) have abundant applications in areas such as electronics, energy, environment industries, biosensors, nano devices, theranostic platforms, etc. Nanoparticles can increase the solubility and stability of drug‐loaded materials, enhance their internalisation, protect them from initial destruction in the biological system, and lengthen their circulation time. The biological interaction of proteins present in the body fluid with NMs can change the activity and natural surface properties of NMs. The size and charge of NMs, properties of the coated and uncoated NMs, nature of proteins, cellular interactions direct their internalisation pathway in the cellular system. Thus, the present review emphasises the impact of coated, uncoated NMs, size and charge, nature of proteins on nano–bio surface interactions and on internalisation with specific focus on cancer cells. The increased activity of NPs may also result in toxicity on health and environment, thus emphasis should be given to assess the toxicity of NMs in the medical field. The e‐data sharing portals of NMs have also been discussed in this review that will be helpful in providing the information about the chemical, physical, biological properties and toxicity of NMs.

Effect of Nano-Carbon Black Surface Modification on Toxicity to Earthworm (Eisenia fetida) Using Filter Paper Contact and Avoidance Test.

Engineered nanomaterials (NMs) may enter the soil through various channels and pose potential harm to soil animals, especially those proactively applied for soil heavy metal remediation. Effects of nano-carbon black (CB) and surface modified carbon black (MCB) on catalase (CAT) activity and malondialdehyde (MDA) content in earthworms exposed on filter paper for 48h were tested. Avoidance test was used to determine hazard of soil treated with 0.015% and 1.5% CB and MCB. Surface properties of NMs were also characterized. MCB has a significant effect on CAT activity at 70 and 1000mg/L (1.1 and 15.7µg/cm2), but has no impact on MDA content in earthworm. Strongly avoidance behavior of worms was also found in soil added 1.5% MCB. Negative charges and oxygen functional groups increased for MCB and its adverse effect on earthworm was higher than CB. The application of MCB in soil remediation warrants more attention.

Mechanochemical Preparation of Novel Polysaccharide-Supported Nb2O5 Catalysts

Polysaccharides extracted from natural sources can be used as starting material for the preparation of nanoparticle supported composites. A novel family of bio-nanocomposites was mechanochemically synthesized by using niobium oxide and enzymatically produced polysaccharides. The structural, textural and surface properties of nanomaterials, were determined by X-Ray diffraction (XRD), nitrogen adsorption-desorption (N₂ porosimetry), pulse chromatography, infrared spectroscopy (ATR-IR) and dynamic light scattering (DLS). Selective oxidation of isoeugenol to vanillin was carried out to demonstrate the catalytic activity of the Nb-polysaccharides nanocomposites. Interestingly, most of our material showed high conversion of isoeugenol (60–70%) with selectivity to vanillin over 40%. The optimum conversion and selectivity were achieved with a reaction time between 8 and 24 h.

Rational engineering of physicochemical properties of nanomaterials for biomedical applications with nanotoxicological perspectives.

Innovative engineered nanomaterials are at the leading edge of rapidly emerging fields of nanobiotechnology and nanomedicine. Meticulous synthesis, unique physicochemical properties, manifestation of chemical or biological moieties on the surface of materials make engineered nanostructures suitable for a variety of biomedical applications. Besides, tailored nanomaterials exhibit entirely novel therapeutic applications with better functionality, sensitivity, efficiency and specificity due to their customized unique physicochemical and surface properties. Additionally, such designer made nanomaterials has potential to generate series of interactions with various biological entities including DNA, proteins, membranes, cells and organelles at nano-bio interface. These nano-bio interactions are driven by colloidal forces and predominantly depend on the dynamic physicochemical and surface properties of nanomaterials. Nevertheless, recent development and atomic scale tailoring of various physical, chemical and surface properties of nanomaterials is promising to dictate their interaction in anticipated manner with biological entities for biomedical applications. As a result, rationally designed nanomaterials are in extensive demand for bio-molecular detection and diagnostics, therapeutics, drug and gene delivery, fluorescent labelling, tissue engineering, biochemical sensing and other pharmaceuticals applications. However, toxicity and risk associated with engineered nanomaterials is rather unclear or not well understood; which is gaining considerable attention and the field of nanotoxicology is evolving promptly. Therefore, this review explores current knowledge of articulate engineering of nanomaterials for biomedical applications with special attention on potential toxicological perspectives.

Standardization and validation of a protocol of zeta potential measurements by electrophoretic light scattering for nanomaterial characterization

Surface properties of nanomaterials are important characteristics influencing the in vivo fate. Today, the most common parameter considered while characterizing nanomaterials surfaces evaluates their surface charge through the determination of the zeta potential. Zeta potential can be deduced from measurement of the electrophoretic mobility of nanomaterials dispersed in aqueous media by well established methods that are described in the standards ISO 13099. Among the different methods, electrophoretic light scattering (ELS) is used in routine in many laboratories. Most marketed apparatus using ELS provide with an apparent zeta potential that depends on experimental conditions and models applied to convert the measured electrophoretic mobility into a value of zeta potential. Although widely used, no validated protocols or approach to perform such a validation were proposed so far to apply the method. This paper was aimed to propose a standardization of a protocol for evaluating zeta potential of nanomaterials by ELS and a methodology to achieve its validation. The robustness, precision and trueness were investigated using reference materials including positive and negative standards. To assess the robustness, experimental factors that could influence results from measurements of zeta potential were considered. These included the batch of measurement cells, the temperature of sample, the type of measurement cells and the analyst giving reliability of protocol for normal usage. Specifics methods of nested designs were developed to investigate robustness and precision and interpret the results using analysis of variance ANOVA. The estimation of the contribution of each factor to the total variance using the estimated mean square values and the equations for expected mean square was used to interpret the ANOVA table. When this method could not be used because of the obtaining of a negative value of the variance, the method based on pooled variances was used to interpret the ANOVA table. The proposed protocol was found robust, accurate and consistent with the standard ISO 13099-2. Uncertainty of the protocol were 14 and 12% for nanomaterials of negative and positive charges respectively proving reliability of results and approving the validity of the protocol used.

Do Surface Defects and Modification Determine the Observed Toxicity of Carbon Nanotubes?

The role of charge and surface modification in the toxicity of CNT is investigated. Two-photon confocal microscopy, Raman microscopy and Lactate Dehydrogenase (LDH) assay are employed to study the effect of CNT on Rat glioma cell line (C6 cells) and rat alveolar macrophage continuous cell line (AM 11). Two-photon confocal microscopy reveals that unmodified CNT is toxic to the C6 cell line but when modified by DNA it becomes relatively non-toxic. Both LDH assay and Raman microscopy show that CNT dispersed in serum is not toxic to the AM11 and C6 cell lines. We have illustrated that the controversy in CNT toxicity will continue, even within the same laboratory, if the surface properties of nanomaterials both before and after modification are not considered and understood before these materials are tested for toxicological properties.