Search Results (106)

Nanomaterials (NMs) have gained tremendous attention in various applications in the modern era. The most significant challenge associated with NMs is their strong propensity to aggregate. The chemical surface modification of NMs has garnered notable attention in managing NM dispersion and aggregation. Among the modification approaches, the silane modification of NMs has generated great interest among researchers as a versatile approach to tailoring the surface characteristics of NMs. This review comprehensively examined the recent advancements in silane modification techniques with a focus on triboelectric nanogenerator (TENG) applications. It provides an overview of silane chemistry and its interaction with diverse NMs, elucidating the underlying mechanisms governing the successful surface functionalization process. This review emphasized the silane modification, such as improved mechanical properties of composites, enhanced electrical and thermal conductivity, functional coatings, water treatment, textile industries, catalysis, membrane applications, and biomedical applications, of various NMs. In particular, the role of silane-modified NMs in advancing energy harvesting technologies was highlighted, showcasing their potential to enhance the performance and stability of next-generation devices. Full article

Background/Objectives: Engineered nanomaterials, particularly silver nanoparticles (AgNPs), have emerged as promising tools in oncology due to their ability to enhance tumor targeting and minimize off-target effects. This study investigates the cytotoxic effects of two different types of AgNPs—citrate-coated (AgNPs-cit) and EG₆OH-coated (AgNPs-EG₆OH)—on colorectal cancer (CRC) cell lines and healthy colonocytes, aiming to assess their potential as selective therapeutic agents. Methods: AgNPs-cit and AgNPs-EG₆OH were synthesized and characterized for size and surface properties. LoVo (microsatellite instability-high) and HT-29 (microsatellite stable) CRC cell lines, along with primary colonocyte cultures from healthy mucosal tissues, were exposed to these nanoparticles. Cytotoxicity was assessed through MTT assays, while morphological changes were observed using fluorescence microscopy. Internalization of the nanoparticles was evaluated by confocal microscopy. Results: AgNPs-cit exhibited significant cytotoxicity in LoVo cells, reducing viability and inducing morphological changes indicative of programmed cell death, especially after 48 h of exposure. In contrast, AgNPs-EG₆OH showed minimal effects on LoVo cells and no significant toxicity on HT-29 cells or primary colonocytes. Confocal microscopy confirmed nanoparticle internalization, with surface functionalization influencing the distribution patterns within cells. Conclusions: This study demonstrates that surface functionalization significantly influences the cytotoxicity of AgNPs, with citrate-coated nanoparticles showing selective effects on microsatellite instability-high CRC cells. These findings underscore the potential of surface-modified nanoparticles for targeted cancer therapy and highlight the importance of tailoring nanoparticle design to optimize therapeutic efficacy while minimizing off-target effects. Full article

Beryllium (Be) is one of the most toxic non-radioactive elements on the periodic table, and its presence or intake can negatively impact both the environment and human health. Classified as a carcinogen, Be is dangerous even at trace concentrations, stressing the necessity of developing reliable methods for quantifying it at very low levels. Spectrometric techniques for quantifying Be vary in sensitivity and applicability, with inductively coupled plasma mass spectrometry (ICP-MS) being the most sensitive for ultra-trace analysis. Flame atomic absorption spectrometry (FAAS) is suitable for higher Be concentrations, but preconcentration techniques can significantly lower detection limits. Electrothermal atomic absorption spectrometry (ETAAS) provides enhanced sensitivity for low-level Be quantification, further optimized using pyrolytically coated graphite tubes and chemical modifiers such as Mg(NO₃)₂ or Pd(NO₃)₂. Effective separation and preconcentration techniques are essential for reliable Be quantification in complex matrices. Liquid-liquid extraction (LLE), including single-drop microextraction (SDME) and dispersive liquid-liquid microextraction (DLLME), have evolved to reduce the use of hazardous solvents. When combined with ETAAS, surfactant-assisted DLLME using agents like cetylpyridinium ammonium bromide (CPAB) and dioctyl sodium sulfosuccinate (AOT) achieves preconcentration factors of approximately 25, reducing LOD to 1 ng/L. Vesicle-mediated DLLME coupled with ETAAS further enhances sensitivity, allowing detection limits as low as 0.01 ng/L in seawater. Cloud-point extraction (CPE), often employing Triton X-114, facilitates Be extraction using complexing agents or nanomaterials like graphene oxide. These advancements are critical for accurately quantifying Be at ultra-trace levels in diverse environmental and biological samples, overcoming challenges posed by low analyte concentrations and matrix interferences. Full article

Layered double hydroxides (LDHs) are a typical class of two-dimensional nanomaterials that present numerous possibilities in both scientific and practical applications. LDHs, with a layered structure and unique interlayer ion-exchange properties, can be utilized to prepare various functional coatings, showing great potential in the field of marine corrosion protection. In this review, the preparation approaches and properties of LDHs are first briefly introduced. Subsequently, various protection types based on LDH-based composite coatings for marine corrosion protection are highlighted, including physical barriers, self-healing, chloride trapping effects, and hydrophobic effects, respectively. Furthermore, critical factors influencing the anti-corrosion performance of composite coatings are discussed in detail. Finally, remaining challenges and future prospects for LDH-modified composite coatings in corrosion protection are proposed. This review provides a distinctive perspective on fabricating LDH-enhanced corrosion-resistant materials, contributing toward the development of multifunctional, intelligent anti-corrosion coatings for diverse applications. Full article

Multiplexed biosensing methods for simultaneously detecting multiple biomolecules are important for investigating biological mechanisms associated with physiological processes, developing applications in life sciences, and conducting medical tests. The development of biosensors, especially those advanced biosensors with multiplexing potentials, strongly depends on advancements in nanotechnologies, including the nano-coating of thin films, micro–nano 3D structures, and nanotags for signal generation. Surface functionalization is a critical process for biosensing applications, one which enables the immobilization of biological probes or other structures that assist in the capturing of biomolecules. During this functionalizing process, nanomaterials can either be the objects of surface modification or the materials used to modify other base surfaces. These surface-functionalizing strategies, involving the coordination of sensor structures and materials, as well as the associated modifying methods, are largely determinative in the performance of biosensing applications. This review introduces the current studies on biosensors with multiplexing potentials and focuses specifically on the roles of nanomaterials in the design and functionalization of these biosensors. A detailed description of the paradigms used for method selection has been set forth to assist understanding and accelerate the application of novel nanotechnologies in the development of biosensors. Full article

The development of skin-protective materials that prevent the adhesion of cnidarian nematocysts and enhance the mechanical strength of these materials is crucial for addressing the issue of jellyfish stings. This study aimed to construct superhydrophobic nanomaterials capable of creating a surface that inhibits nematocyst adhesion, therefore preventing jellyfish stings. We investigated wettability and nematocyst adhesion on four different surfaces: gelatin, polydimethylsiloxane (PDMS), dodecyl trichlorosilane (DTS)-modified SiO₂, and perfluorooctane triethoxysilane (PFOTS)-modified TiO₂. Our findings revealed that an increase in hydrophobicity significantly inhibited nematocyst adhesion. Furthermore, DTS-modified sprayed SiO₂ and PFOTS-modified sprated TiO₂ were further enhanced with low-surface-energy substances—cellulose nanofibers (CNF) and chitin nanocrystals (ChNCs)—to improve both hydrophobicity and mechanical strength. After incorporating CNF and ChNCs, the surface of s-TiO₂-ChNCs exhibited a contact angle of 153.49° even after undergoing abrasion and impact tests, and it maintained its hydrophobic properties with a contact angle of 115.21°. These results indicate that s-TiO₂-ChNCs can serve as an effective skin coating to resist tentacle friction. In conclusion, this study underscores the importance of utilizing hydrophobic skin materials to inhibit the adhesion of tentacle nematocysts, providing a novel perspective for protection against jellyfish stings. Full article

Fluorescent nanodiamonds (FNDs) are carbon-based nanomaterials that emit bright, photostable fluorescence and exhibit a modifiable surface chemistry. Myeloid-derived suppressor cells (MDSCs) are an immunosuppressive cell population known to expand in cancer patients and contribute to worse patient outcomes. To target MDSC, glycidol-coated FND were conjugated with antibodies against the murine MDSC markers, CD11b and GR1 (dual-Ab FND). In vitro, dual-Ab FND uptake by murine MDSC was significantly higher than IgG-coated FND (94.7% vs. 69.0%, p < 0.05). In vivo, intra-tumorally injected dual-Ab FND primarily localized to the tumor 2 and 24 h post-injection, as measured by in vivo fluorescence imaging and flow cytometry analysis of the spleen and tumor. Dual-Ab FND were preferentially taken up by intra-tumoral MDSC, representing 87.1% and 83.0% of FND+ cells in the tumor 2 and 24 h post-injection, respectively. Treatment of mice with anti-PD-L1 immunotherapy prior to intra-tumoral injection of dual-Ab FND did not significantly alter the uptake of FND by MDSC. These results demonstrate the ability of our novel dual-antibody conjugated FND to target MDSC and reveal a potential strategy for targeted delivery to other specific immune cell populations in future cancer research. Full article

Concrete coatings show significant promise in shielding concrete substrates from corrosion by effectively resisting harmful ions and moisture. Thanks to their practicality, high efficiency, and cost-effectiveness, coatings are considered a potent technique for enhancing the chloride resistance of reinforced concrete structures. Over recent decades, extensive research has concentrated on employing coatings to bolster concrete’s ability to withstand chloride penetration. This paper provides a holistic review of the current studies on chloride infiltration in concrete surfaces treated with coating materials, primarily focused on chloride resistance improvement efficiency and chloride transport modeling. Firstly, by comparing the functions of assorted coatings, four inherent protection mechanisms are summarized and elaborated thoroughly. Afterwards, the chloride resistance improvement efficiency of assorted coatings reported in current studies are reviewed and compared in great detail, with a specific focus on inorganic, organic, and organic–inorganic composite coatings. Furthermore, the theoretical research about methodologies for chloride transport behavior prediction is summarized. Finally, this paper outlines the potential research directions in this field and the theoretical, technical, and practical application challenges. This review not only identifies critical areas necessitating further investigation and problem-solving in this domain but also aids in selecting appropriate coating materials and refining corrosion management strategies. Full article

This research analyzed the mechanisms of work and modified a colorimetric nanosensor to make it more cost-effective for the detection of Escherichia coli (E. coli) in water. The base nanosensors modified herein rely on a competitive binding detection mechanism, where positively charged gold nanoparticles coated with polyethyleneimine (PEI-AuNPs) preferably bind to negatively charged E. coli in the presence of β-galactosidase ($\mathsf{\beta }$-Gal) enzymes and chlorophenol red β-d-galactopyranosides (CPRG). The positive surface charge of the nanoparticle, rather than nanoparticle composition or type of chemical coating on its surface, was hypothesized herein as the governing factor for the nanosensor functionality. Thus, positively charged nanoparticles and polymers were tested as potential alternatives for gold nanoparticles for detecting E. coli. Positively charged silver and iron oxide nanoparticles coated with branched PEI detected E. coli as low as 10⁵ and 10⁷ colony-forming units per milliliter (CFU/mL), respectively. Furthermore, the branched PEI polymer itself (without nanomaterial) detected E. coli at 10⁷ CFU/mL. These findings suggest that the positive charge, rather than the nanoparticle type was likely responsible for the detection of E. coli using the competitive binding approach. Therefore, other types of recyclable and cost-effective nanomaterials and polymers can be developed for E. coli detection using this rapid colorimetric sensing technique. Full article

The exceptional corrosion resistance and combined physical and chemical self-cleaning capabilities of superhydrophobic photocatalytic coatings have sparked significant interest among researchers. In this paper, we propose an economical and eco-friendly superhydrophobic epoxy resin coating that incorporates SiO₂@CuO/HDTMS nanoparticles modified with Hexadecyltrimethoxysilane (HDTMS). The application of superhydrophobic coatings effectively reduces the contact area between the metal surface and corrosive media, leading to a decreased corrosion rate. Additionally, the incorporation of nanomaterials, exemplified by SiO₂@CuO core–shell nanoparticles, improves the adhesion and durability of the coatings on aluminum alloy substrates. Experimental data from Tafel curve analysis and electrochemical impedance spectroscopy (EIS) confirm the superior corrosion resistance of the superhydrophobic modified aluminum alloy surface compared to untreated surfaces. Estimations indicate a significant reduction in corrosion rate after superhydrophobic treatment. Furthermore, an optical absorption spectra analysis of the core–shell nanoparticles demonstrates their suitability for photocatalytic applications, showcasing their potential contribution to enhancing the overall performance of the coated surfaces. This research underscores the promising approach of combining superhydrophobic properties with photocatalytic capabilities to develop advanced surface modification techniques for enhanced corrosion resistance and functional properties in diverse industrial settings. Full article

The microbial hybrid system modified by magnetic nanomaterials can enhance the interfacial electron transfer and energy conversion under the stimulation of a magnetic field. However, the bioelectrocatalytic performance of a hybrid system still needs to be improved, and the mechanism of magnetic field-induced bioelectrocatalytic enhancements is still unclear. In this work, γ-Fe₂O₃ magnetic nanoparticles were coated on a Shewanella putrefaciens CN32 cell surface and followed by placing in an electromagnetic field. The results showed that the electromagnetic field can greatly boost the extracellular electron transfer, and the oxidation peak current of CN32@γ-Fe₂O₃ increased to 2.24 times under an electromagnetic field. The enhancement mechanism is mainly due to the fact that the surface modified microorganism provides an elevated contact area for the high microbial catalytic activity of the outer cell membrane’s cytochrome, while the magnetic nanoparticles provide a networked interface between the cytoplasm and the outer membrane for boosting the fast multidimensional electron transport path in the magnetic field. This work sheds fresh scientific light on the rational design of magnetic-field-coupled electroactive microorganisms and the fundamentals of an optimal interfacial structure for a fast electron transfer process toward an efficient bioenergy conversion. Full article

This study aims to develop a microelectrode array-based neural probe that can record dopamine activity with high stability and sensitivity. To mimic the high stability of the gold standard method (carbon fiber electrodes), the microfabricated platinum microelectrode is coated with carbon-based nanomaterials. Carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNTs) and carbon quantum dots (CQDs) were selected for this purpose, while a conductive polymer like poly (3-4-ethylene dioxythiophene) (PEDOT) or polypyrrole (PPy) serves as a stable interface between the platinum of the electrode and the carbon-based nanomaterials through a co-electrodeposition process. Based on our comparison between different conducting polymers and the addition of CQD, the CNT–CQD–PPy modified microelectrode outperforms its counterparts: CNT–CQD–PEDOT, CNT–PPy, CNT–PEDOT, and bare Pt microelectrode. The CNT–CQD–PPy modified microelectrode has a higher conductivity, stability, and sensitivity while achieving a remarkable limit of detection (LOD) of 35.20 ± 0.77 nM. Using fast-scan cyclic voltammetry (FSCV), these modified electrodes successfully measured dopamine’s redox peaks while exhibiting consistent and reliable responses over extensive use. This electrode modification not only paves the way for real-time, precise dopamine sensing using microfabricated electrodes but also offers a novel electrochemical sensor for in vivo studies of neural network dynamics and neurological disorders. Full article

Shape memory and self-healing polymer nanocomposites have attracted considerable attention due to their modifiable properties and promising applications. The incorporation of nanomaterials (polypyrrole, carboxyl methyl cellulose, carbon nanotubes, titania nanotubes, graphene, graphene oxide, mesoporous silica) into these polymers has significantly enhanced their performance, opening up new avenues for diverse applications. The self-healing capability in polymer nanocomposites depends on several factors, including heat, quadruple hydrogen bonding, π–π stacking, Diels–Alder reactions, and metal–ligand coordination, which collectively govern the interactions within the composite materials. Among possible interactions, only quadruple hydrogen bonding between composite constituents has been shown to be effective in facilitating self-healing at approximately room temperature. Conversely, thermo-responsive self-healing and shape memory polymer nanocomposites require elevated temperatures to initiate the healing and recovery processes. Thermo-responsive (TRSMPs), light-actuated, magnetically actuated, and Electrically actuated Shape Memory Polymer Nanocomposite are discussed. This paper provides a comprehensive overview of the different types of interactions involved in SMP and SHP nanocomposites and examines their behavior at both room temperature and elevated temperature conditions, along with their biomedical applications. Among many applications of SMPs, special attention has been given to biomedical (drug delivery, orthodontics, tissue engineering, orthopedics, endovascular surgery), aerospace (hinges, space deployable structures, morphing aircrafts), textile (breathable fabrics, reinforced fabrics, self-healing electromagnetic interference shielding fabrics), sensor, electrical (triboelectric nanogenerators, information energy storage devices), electronic, paint and self-healing coating, and construction material (polymer cement composites) applications. Full article

Wear performance is integral to component longevity, minimizing industrial waste and excess energy costs in a wide variety of applications. Anodized aluminum oxide (AAO) has many beneficial properties leading to its wide use across industries as a surface treatment for many aluminum components, but the wear properties of the coating could be improved significantly. Here, we used an electrochemical method to incorporate molybdenum disulfide (MoS₂), a nanomaterial used as a dry lubricant, to modify alloys of aluminum during AAO preparation. Using Raman spectroscopy and tribological scratch measurements, we thoroughly characterized the structure and wear behavior of the films. The MoS₂ deposition procedure was optimal on aluminum 5052 anodized in higher acid concentrations, with friction coefficients at around 0.05 (~10× better than unmodified AAO). Changing anodization conditions to produce harder films with smaller pores led to worsened wear properties, likely because of lower MoS₂ content. Studying a commercial MoS₂/AAO film of a different Al alloy (7075) showed that a heat treatment step intended to fully convert all deposited MoS_x species to MoS₂ can adversely affect wear in some alloys. While Al 6061 and 1100 produced films with worse wear performance compared to Al 5052 or 7075, our results show evidence that acid cleaning after initial anodization likely removes residual alloying elements, affecting MoS₂ incorporation. This study demonstrates a nanomaterial modified AAO film with superior wear characteristics to unmodified AAO and relates fabrication procedure, film structure, and practical performance. Full article

Novel nanomaterials used for wound healing should have many beneficial properties, including high biological and antibacterial activity. Immobilization of proteins can stimulate cell migration and viability, and implanted Ag ions provide an antimicrobial effect. However, the ion implantation method, often used to introduce a bactericidal element into the surface, can lead to the degradation of vital proteins. To analyze the surface structure of nanofibers coated with a layer of plasma COOH polymer, fibronectin/gentamicin, and implanted with Ag ions, a new X-ray photoelectron spectroscopy (XPS) fitting method is used for the first time, allowing for a quantitative assessment of surface biomolecules. The results demonstrated noticeable changes in the composition of fibronectin- and gentamicin-modified nanofibers upon the introduction of Ag ions. Approximately 60% of the surface chemistry has changed, mainly due to an increase in hydrocarbon content and the introduction of up to 0.3 at.% Ag. Despite the significant degradation of fibronectin molecules, the biological activity of Ag-implanted nanofibers remained high, which is explained by the positive effect of Ag ions inducing the generation of reactive oxygen species. The PCL nanofibers with immobilized gentamicin and implanted silver ions exhibited very significant antipathogen activity to a wide range of Gram-positive and Gram-negative strains. Thus, the results of this work not only make a significant contribution to the development of new hybrid fiber materials for wound dressings but also demonstrate the capabilities of a new XPS fitting methodology for quantitative analysis of surface-related proteins and antibiotics. Full article