Surface Modification Of Nanoparticles Research Articles

Enhanced photocatalytic and antibacterial properties of silver–zirconia nanoparticles for environmental pollution treatment

Abstract Silver–zirconia nanoparticles (Ag–ZrO2 NPs) were synthesized via an in situ strategy at room temperature using NaBH4 as a reducing agent. The surface modification of ZrO2 nanoparticles with nano silver was confirmed through various characterization techniques including Fourier Transform Infrared Spectroscopy (FTIR), UV–vis Diffuse Reflectance Spectroscopy (UV–vis DRS), X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). The obtained results demonstrated that Ag nanoparticles, with a crystallite size of approximately 12 nm, were uniformly distributed on the surface of ZrO2 nanoparticles. The incorporation of Ag nanoparticles to the ZrO2 nanoparticles led to increasing the light absorption ability and reducing the band gap of Ag–ZrO2 nanoparticles, thereby enhancing their photocatalytic performance under infrared lamp exposure. When 1 g/L of Ag–ZrO2 nanoparticles was employed to methylene blue (MB) solution, the degradation of MB reached 90 % after 5 h of exposure. Additionally, the Ag–ZrO2 nanoparticles exhibited a high antibacterial activity against two bacterial strains, E. coli and S. aureus. These findings highlight the potential of Ag–ZrO2 nanoparticles as effective materials for environmental pollution treatment through advanced oxidation processes.

Dielectric and mechanical properties of cement pastes incorporated with magnetically aligned reduced graphene oxide

Magnetic nanocomposites were fabricated by attaching surface-modified magnetite nanoparticles to the surface of reduced graphene oxide (rGO) in this study. By applying an external magnetic field, the rGO were highly aligned in the cement paste. The orientation factor of aligned rGO was found to be 0.71 by analyzing the polarized Raman scattering spectra. The alignment of the rGO contributed to both the mechanical and dielectric properties of the cement paste. The flexural strength of the specimen with aligned rGO improved by 48% compared with that of the cement pastes with randomly distributed rGO. The dielectric constant at 100 Hz of the specimen with aligned rGO was increased by 271% compared with that of cement pastes with randomly distributed rGO. A modified rule of mixtures was proposed to predict their mechanical and dielectric properties. This study offers insight on the development of nanofiller-incorporated cement-based materials with enhanced mechanical and dielectric properties.

Surface modification of hollow gold nanoparticles conducted by incorporating cancer cell membrane and AS1411 aptamer, aiming to achieve a dual-targeted therapy for colorectal cancer

Due to its inherent membrane structure, a nanostructure enveloped by an active cell membrane possesses distinctive characteristics such as prolonged presence in the bloodstream, precise identification capabilities, and evasion of immune responses. This research involved the production of biomimetic nanoparticles, specifically hollow gold nanoparticles (HGNPs) loaded with methotrexate (MTX), which were further coated with cancer cell membrane. These nanoparticles were then adorned with AS1411 aptamer to serve as a targeting agent (Apt-CCM-HG@MTX). The nanoplatform demonstrated precise targeting towards cancer cells due to its dual-targeting characteristic (AS1411 aptamer and C26 cancer cell membrane), exhibiting uniformity in distribution. It also displayed a desirable response to photothermal stimulation, controlled release of drugs, and exceptional properties for fluorescence imaging. The system was composed of spherical HGNPs measuring 51.33 ± 5.70 nm in diameter, which were effectively loaded with MTX using a physical absorption method. The encapsulation efficiency achieved was recorded at 79.54 %, while the loading efficiency reached 38.21 %. The targeted formulation demonstrated a noteworthy mortality of approximately 45 % in the nucleolin positive cell line, C26, as determined by in vitro cytotoxicity assays. As a result of the functionalization process applied to the homologous binding adhesion molecules found in cancer cell membranes and targeting ability of AS1411 aptamer, Apt-CCM-HG@MTX demonstrated a substantial enhancement in targeting tumors and facilitating cellular uptake during in vivo experiments. Furthermore, under NIR radiation the photothermal effect exhibited by Apt-CCM-HG@MTX in the tumor area was notably robust due to the distinctive attributes of HGNPs. The conclusions obtained from this study have the potential to assist in adopting a bioinspired strategy that will significantly improve the effective management of MTX and therapy for individuals with colorectal cancer.

Enhancing the Output Performance of Triboelectric Nanogenerator Through Regulation of its Internal Nano-Architecture.

Triboelectric Nanogenerator (TENG) has proven highly effective in converting mechanical energy into electrical energy. Previous research on manipulating microstructure for performance enhancement primarily focused on the surface of TENGs. In this study, an innovative bottom-up strategic design to control the internal nano-architecture for the enhanced output of TENG is proposed. This multiscale structural design strategy consists of defect chemistry (angstrom-scale), surface modification (nano-scale), and spatial regulation of nanoparticles (meso-scale), which helps explore the optimal utilization of TENG's internal structure. After fine-tuning the nano-architecture, the output voltage is significantly increased. This optimized TENG serves as a robust platform for developing self-powered systems, including self-powered electrochemical chlorination systems for sterilization. Additionally, through the utilization of multiscale simulations (density functional theory, all-atom molecular dynamics, and dissipative particle dynamics), the underlying mechanisms governing how the optimized nanoparticle-polymer interface and spatial arrangement of nanoparticles influence the storage and transfer of charges are comprehensively elucidated. This study not only demonstrates the effectiveness of manipulating internal nano-architecture to enhance TENG performance for practical applications but also provides invaluable insights into structural engineering for TENG advancement.

New Cu(II) Schiff-base complex modified on magnetic nanoparticles: Oxidation and DFT investigation

A copper magnetic nanocatalyst was facilely synthesized by surface modification of silica magnetic nanoparticles (Fe3O4@SiO2) via reaction with 3-aminopropyltrimethoxysilane (Fe3O4@SiO2@APTMS), followed by a subsequent reaction with thiophene-2-carbaldehyde to form a Schiff base (Fe3O4@SiO2@SB). Sequentially, reaction with Cu(CH3COO)2·H2O in ethanol yielded Fe3O4@SiO2@[SB@Cu] (CH3COO)2. This nanomagnetic catalyst was comprehensively characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), and Vibrating Sample Magnetometry (VSM) techniques. The catalytic proficiency of these nanoparticles was evaluated through alkene and alcohol oxidation reactions. Under optimized conditions, the nanocatalyst exhibited significant efficacy in oxidizing styrene, cyclohexene, and benzyl alcohol, with notable selectivity values of 88 %, 100 %, and 100 % for the respective formation of styrene epoxide, 2-cyclohexene-1-one, and benzoic acid. The heterogeneous copper nanocatalyst offers advantages, including high conversion rates, facile separation, and exceptional selectivity in alkene and alcohol oxidation. Additionally, this study investigated density functional theory (DFT) methods, encompassing geometric optimization, natural charge analysis, molecular electrostatic potential maps, and vibrational normal modes of the chelating ligands.

Remediation of toluidine blue O dye from aqueous solution using surface functionalized magnetite nanoparticles

Abstract In the current study, tannic acid-functionalized iron oxide nanoparticles have been synthesized using a cost-effective co-precipitation method and subsequently characterized using various instrumentation techniques such as Fourier transform infrared spectroscopy, X-ray diffractometer, field emission scanning electron microscopy, and thermal gravimetric analysis. Further, these surface-modified magnetite nanoparticles have been used for the adsorption of toluidine dye from an aqueous solution. The adsorption process was accompanied using batch procedure, and influences of several factors such as adsorbent dose, contact time, pH, temperature, and initial concentration of adsorbate were inspected concurrently. The maximum adsorption capacity of tannic acid-functionalized magnetite nanoparticles was found to be 50.68 mg/g. The adsorption process was observed to follow the Temkin isotherm model, whereas the kinetic study was well described by pseudo-second order. The thermodynamic study revealed the adsorption process to be endothermic and spontaneous in nature with a high degree of freedom between adsorbent and adsorbate. Therefore, the study indicated that the tannic acid-functionalized magnetite nanoparticles have promising adsorption capability and can be used as an excellent adsorbent for the removal of toluidine blue O dye from the aqueous solution.

HYDROXYAPATITE NANOPARTICLES: A REVIEW OF THEIR EMERGING ROLE IN DRUG DELIVERY APPLICATIONS

This literature review assesses existing research on hydroxyapatite-based drug delivery systems, with a focus on evaluating their effectiveness. Researchers are actively exploring strategies to enhance drug loading capacity, involving surface modifications of nanoparticles and the innovation of novel drug encapsulation techniques. Elevating drug loading has the potential to clearly increase the therapeutic efficacy of these systems. Stability issues also present a challenge in the clinical translation of nanoparticle-based drug delivery systems. Furthermore, scientists are underway to minimize potential side effects by judiciously selecting biocompatible materials for nanoparticle synthesis and conducting comprehensive toxicity studies before advancing to clinical trials.

Carbon-Coated Iron Oxide Nanoparticles Promote Reductive Stress-Mediated Cytotoxic Autophagy in Drug-Induced Senescent Breast Cancer Cells.

The surface modification of magnetite nanoparticles (Fe3O4 NPs) is a promising approach to obtaining biocompatible and multifunctional nanoplatforms with numerous applications in biomedicine, for example, to fight cancer. However, little is known about the effects of Fe3O4 NP-associated reductive stress against cancer cells, especially against chemotherapy-induced drug-resistant senescent cancer cells. In the present study, Fe3O4 NPs in situ coated by dextran (Fe3O4@Dex) and glucosamine-based amorphous carbon coating (Fe3O4@aC) with potent reductive activity were characterized and tested against drug-induced senescent breast cancer cells (Hs 578T, BT-20, MDA-MB-468, and MDA-MB-175-VII cells). Fe3O4@aC caused a decrease in reactive oxygen species (ROS) production and an increase in the levels of antioxidant proteins FOXO3a, SOD1, and GPX4 that was accompanied by elevated levels of cell cycle inhibitors (p21, p27, and p57), proinflammatory (NFκB, IL-6, and IL-8) and autophagic (BECN1, LC3B) markers, nucleolar stress, and subsequent apoptotic cell death in etoposide-stimulated senescent breast cancer cells. Fe3O4@aC also promoted reductive stress-mediated cytotoxicity in nonsenescent breast cancer cells. We postulate that Fe3O4 NPs, in addition to their well-established hyperthermia and oxidative stress-mediated anticancer effects, can also be considered, if modified using amorphous carbon coating with reductive activity, as stimulators of reductive stress and cytotoxic effects in both senescent and nonsenescent breast cancer cells with different gene mutation statuses.

Anticancer and Antibacterial Properties of Curcumin-Loaded Mannosylated Solid Lipid Nanoparticles for the Treatment of Lung Diseases.

Lung cancer and Mycobacterium avium complex infection are lung diseases associated with high incidence and mortality rates. Most conventional anticancer drugs and antibiotics have certain limitations, including high drug resistance rates and adverse effects. Herein, we aimed to synthesize mannose surface-modified solid lipid nanoparticles (SLNs) loaded with curcumin (Man-CUR SLN) for the effective treatment of lung disease. The synthesized Man-CUR SLNs were analyzed using various instrumental techniques for structural and physicochemical characterization. Loading curcumin into SLNs improved the encapsulation efficiency and drug release capacity, as demonstrated by high-performance liquid chromatography analysis. Furthermore, we characterized the anticancer effect of curcumin using the A549 lung cancer cell line. Cells treated with Man-CUR SLN exhibited an increased cellular uptake and cytotoxicity. Moreover, treatment with free CUR could more effectively reduce cancer migration than treatment with Man-CUR SLNs. Similarly, free curcumin elicited a stronger apoptosis-inducing effect than that of Man-CUR SLNs, as demonstrated by reverse transcription-quantitative PCR analysis. Finally, we examined the antibacterial effects of free curcumin and Man-CUR SLNs against Mycobacterium intracellulare (M.i.) and M.i.-infected macrophages, revealing that Man-CUR SLNs exerted the strongest antibacterial effect. Collectively, these findings indicate that mannose-receptor-targeted curcumin delivery using lipid nanoparticles could be effective in treating lung diseases. Accordingly, this drug delivery system can be used to target a variety of cancers and immune cells.

Enhanced oxidation stability and proton conductivity of sulfonated poly(arylene ether ketone sulfone)s via embedment of surface-modified ceria nanoparticles

Sulfonated poly(arylene ether ketone sulfone)s (SPAEKS) were prepared by polycondensation reaction as polymer matrix. Dopamine hydrochloride was sulfonated and then modified onto the surface of the ceria (CeO2) nanoparticles. The sulfonated dopamine ceria (SPD@CeO2) was added to the polymer matrix as an inorganic nanofiller to prepare a series of composite membranes. The structure and morphology of modified inorganic nanoparticles and membranes were characterized and analyzed by means of SEM, 1H NMR, PXRD and FTIR. Among all the composite membranes obtained, S-SPD@CeO2-2 (the quality of the SPD@CeO2 percentage was 2%) had the most outstanding comprehensive performance. Oxidative stability of S-SPD@CeO2-2 reached 95.33% due to the free radical scavenging effect of CeO2. At 80 °C, 100% relative humidity (RH), the proton conductivity of S-SPD@CeO2-2 was 218.93 mS cm−1. Meanwhile, this membrane also had good mechanical property (Young's modulus was 1332.59 MPa) and dimensional stability (swelling ratio was 34.34% at 80 °C). Besides, the maximum power density and open circuit voltage (OCV) of S-SPD@CeO2-2 membranes reached 445.48 mW cm−2 and 0.917 V. Both of the above results were better than pure membranes (304.45 mW cm−2 and 0.872 V). Comprehensive the above data, S-SPD@CeO2-2 had considerable potential for application as fuel cell diaphragm.

Influence of ionic liquid modified gold nanoparticles on conformational transition of poly(N-isopropylacrylamide)-b-poly(acryloylmorpholine) block copolymer

Utilizing stimuli-responsive polymers for surface modification of nanoparticle allows the adjustment of properties for individual system; however, limited research explores the impact of ionic liquid-modified gold nanoparticles (AuNPs) on the conformational phase transition of block copolymers. Herein, we synthesized poly(N-isopropylacrylamide)-b-poly(acryloylmorpholine) (PNIPAM-b-PACMO) copolymers by reversible addition − fragmentation chain-transfer polymerization and investigated the effect of ionic-liquid modified AuNPs (IL-AuNPs) on the aggregation behavior of the copolymer. Copolymerization of PNIPAM with PACMO shifted the lower critical solution temperature (LCST) towards higher temperature in comparison to LCST value of PNIPAM. Addition of IL-AuNPs further raises the transition temperature in concentration dependent manner. A more significant alteration in the transition temperature was observed in the presence of IL-AuNPs with a higher alkyl chain length. The variation in transition temperature of the copolymer by different IL-AuNPs yields benefits in the temperature responsive properties which can helpful for various applications.

Exploiting Hydrogen Interaction of Drugs and Biodegradable Scaffolds Using Nanoparticles Loaded Nanofibers

AbstractThis study presents a detailed investigation of the structural and surface modifications of Fe3O4 nanoparticles (NPs). Fourier Transform Infrared (FTIR) spectroscopy was utilized to analyze the distinct characteristic peaks of Fe3O4 NPs and their subsequent modifications with stearic acid (ST) layers. The FTIR analysis revealed characteristic peaks at 580 cm−1, and 441 cm−1, corresponding to the Fe‐O stretching vibrations of the bulk Fe3O4 NPs. The successful loading of stearic acid onto the Fe3O4 NPs was confirmed by the appearance of new peaks at 1413 cm−1 and 2908 cm−1, indicative of the asymmetric CH2 stretch and CH3 umbrella vibration modes of stearic acid. UV‐Vis spectroscopy further corroborated the efficient loading of tetracycline and ibuprofen onto Fe3O4/DST nanoparticles, as evidenced by changes in absorption spectra. N2 adsorption‐desorption isotherms illustrated the presence of micro and meso pores on the surface of Fe3O4 NPs, with alterations in pore volume and diameter post‐surface modification and drug loading. Evaluation of magnetic properties indicated a reduction in saturation magnetization after surface modification and drug loading, attributed to changes in homogeneity and surface moments. Differential Reflectance Spectroscopy (DRS) and Raman spectroscopy elucidated distinctive peaks and shifts in spectra, confirming the composition and structural changes in drug‐loaded nanofibers.

Su Bazlı Nanoakışkanların Hazırlanmasında Kullanılan Yeni Yüzey Modifiye Fe3O4 Nanopartiküllerinin Uzun Vadeli Kararlılıklarının İncelenmesi

Nanofluids are produced by suspending different solid nano-size materials (metal and nonmetal) in a base liquid and are often used in energy systems to increase thermal performance and heat transfer rate. The main problem observed in nanofluids used in heat transfer applications is their instability. Researchers have developed and proposed some solutions to obtain stable nanofluids. One of the most important solutions, is the nanoparticles surface modification method. In this work, Fe3O4 nanoparticles were subjected to chemical processes and their surfaces were modified. Three different modified nanoparticles were synthesized, which are Fe3O4@SiO2@Si(CH2)3-IM [Cl], Fe3O4@Si(CH2)3-IM [Cl], and Fe3O4@SiO2&Si(CH2)3-IM [Cl] nanoparticles. The nanofluids were prepared in 0.2% Vol. fraction by using the produced particles in base fluid which was distilled water, and stability of nanofluids were observed for 3 months. Nanofluids were subjected to ultrasonication for 3.5 h to obtain homogeneous nanofluid. Not modified water-based Fe3O4 nanofluid completely collapsed in approximately 1 week. In modified nanofluids, although sedimentation occurred, it was observed that a certain amount of the particles remained suspended even after 3 months. The most important analyses in this study are Scanning Electron Microscope, X-Ray Diffraction, and Transmission Electron Microscope.

Zn induced surface modification of stable goethite nanoparticles for improved regenerative phosphate adsorption

Iron oxide-based adsorbents showed potential to reach ultra-low phosphorus (P) concentrations to prevent eutrophication and recover P. High affinity, high capacity at low P concentrations (<1 mg L−1), good stability, and reusability of the adsorbent are key factors for economic viability. In this study, nanoparticles of goethite (α-FeOOH), a highly stable phase, have been synthesized with increasing Zn2+-doping, 0–20 %at. Zn/Fe, to manipulate the surface properties, following the results of a previous work. Mössbauer spectroscopy showed preserved goethite phase and increased point of zero charge (pzc) at low Zn-doping percentages, while at higher percentages (>5%at.) co-existing phases with increased specific surface area formed. Low concentrations (0.1–10 mg L−1) batch adsorption tests showed increased P removal per unit mass with increasing doping. However, the highest pzc, affinity and P removal per unit area were observed for the 5%at. doped sample, suggesting this dopant concentration to provide the most effective surface. A regeneration test, performed at a lower pH than usual, showed preserved, even improved P desorption with increasing doping. Mössbauer spectroscopy showed that the nanoparticle phase and composition, up to 5%at., doping was preserved throughout the process. These results are promising to develop a stable effective Zn-doped goethite-based adsorbent for P recovery at ultra-low concentrations.

Cobalt oxide nanoparticles functionalized with glucose and conjugated to Ellagic acid (Co3O4@Glu-Ellagic acid NPs) induce apoptotic genes in HepG2, liver cancer cell line

Surface modification of metal nanoparticles can be a solution to obtain more efficient and biocompatible drugs. In this study, the anticancer mechanism of cobalt oxide nanoparticles (NPs) functionalized with glucose and conjugated with Ellagic acid (Co3O4@Glu-Ellagic acid NPs) in a liver cancer cell line was investigated. Physicochemical characteristics of NPs were investigated by Fourier-transform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM), (Scanning Electron Microscopy) SEM, X-Ray diffraction analysis (XRD), Energy Dispersive Spectroscopy mapping (EDS-mapping), Dynamic light scattering (DLS), and zeta potential. Cytotoxicity of Co3O4@Glu-Ellagic acid NPs in normal (THLE2) and cancer (HepG2) hepatocyte cell lines was characterized by MTT and flow cytometry assays. Relative expression of the CASP8, CASP9, and p53 genes was assessed by Real-Time PCR. The synthesized nanoparticles were spherical, without considerable agglomeration, and their size was in the range of 20 to 60 nm. Surface charge and DLS size were − 30.1 mV and 280 nm, respectively. Treatment of the studied cells with the nanoparticles displayed their antiproliferative potential; however, liver cancer cells were considerably more sensitive to the nanoparticles than normal hepatocyte cells. The 50 % inhibitory concentration of Co3O4@Glu-Ellagic acid NPs for normal and cancer hepatocyte cells were 201 and 97 μg/mL, respectively. Treating HepG2 cells with Co3O4@Glu-Ellagic acid NPs led to a significant increase in the percentage of apoptotic cells (from 0.66 % to 50.8 %) and expression of the CASP8, CASP9, and p53 genes by 2.88, 2.11, and 2.0 folds that suggests apoptogenic property of the nanoparticles through activation of the intrinsic and extrinsic apoptosis pathways. Measuring Reactive Oxygen Species (ROS) level showed that in treated cancer cells with Co3O4@Glu-Ellagic acid nanoparticles the ROS level increased. Moreover, Hoechst staining indicated the anti-tumor effect of Co3O4@Glu-Ellagic acid NP by appearance of apoptotic bodies in HepG2 cells. This work revealed that Co3O4@Glu-Ellagic acid NPs are potent apoptogenic agent against liver cancer cells.

A metal-organic framework (MOF) built on surface-modified Cu nanoparticles eliminates tumors via multiple cascading synergistic therapeutic effects

Tumors produce a hypoxic environment that greatly influences cancer treatment, and conventional chemotherapeutic drugs cannot selectively accumulate in the tumor region because of the lack of a tumor targeting mechanism, causing increased systemic toxicities and side effects. Hence, designing and developing new nanoplatforms that combine multimodal therapeutic regimens is essential to improve tumor therapeutic efficacy. Herein, we report the synthesis of ultrafine Cu nanoparticles loaded with a drug combination of cisplatin (Pt) and 1-methyl-d-tryptophan (1-MT) and externally coated with 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) photosensitizer, polydopamine (PDA) and CaO2 of MIL-101(Fe) as a new nanoplatform (Cu@MIL-101@PMTPC). The nanoplatform synergistically combined chemodynamic therapy (CDT), photodynamic therapy (PDT), and immunochemotherapy. The Fe3+ in MIL-101(Fe) and the surface Cu nanoparticles exhibited strong ability to consume intracellular glutathione (GSH), thereby generating a Fenton-like response in the tumor microenvironment (TME) with substantial peroxidase (POD)-like and superoxide dismutase (SOD)-like activities. In this design, we used the indoleamine 2,3-dioxygenase (IDO) inhibitor 1-MT to overcome chemotherapy-induced immune escape phenomena including enhanced CD8+ and CD4+ T cell expression, interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) production, and accelerated immunogenic cell death. The targeted release of cisplatin loaded into Cu@MIL-101@PMTPC also reduced toxic side effects of chemotherapy. TCPP generated a large amount of singlet oxygen (1O2) upon specific laser irradiation to effectively kill tumor cells. CaO2 on the outer layer generated oxygen (O2) and hydrogen peroxide (H2O2) to ameliorate hypoxia in the tumor microenvironment, enhance the PDT effect, and provide a continuous supply of H2O2 for the Fenton-like reaction. Thus, this nanocarrier platform exhibited a powerful chemodynamic, photodynamic, and immunochemotherapeutic cascade, providing a new strategy for cancer treatment.

Exposure to different surface-modified polystyrene nanoparticles caused anxiety, depression, and social deficit in mice via damaging mitochondria in neurons

Nanoplastics (NPs) are unavoidable hazardous materials that result from the human production and use of plastics. While there is evidence that NPs can bioaccumulate in the brain, no enough research regarding the pathways by which NPs reach the brain was conducted, and it is also urgently needed to evaluate the health threat to the nervous system. Here, we observed accumulation of polystyrene nanoplastics (PS-NPs) with different surface modifications (PS, PS-COOH, and PS-NH2) in mouse brains. Further studies showed that PS-NPs disrupted the tight junctions between endothelial cells and transport into endothelial cells via the endocytosis and macropinocytosis pathways. Additionally, NPs exposure induced a series of alternations in behavioral tests, including anxiety- and depression-like changes and impaired social interaction performance. Further results identified that NPs could be internalized into neurons and localized in the mitochondria, bringing about mitochondrial dysfunction and a concurrent decline of ATP production, which might be associated with abnormal animal behaviors. The findings provide novel insights into the neurotoxicity of NPs and provide a basis for the formulation of policy on plastic production and usage by relevant government agencies.

The Role of Surface Modification of Silica-Coated Fe3O4 Nanoparticles in the Structure and Enzyme Activity of Lysozyme

The Role of Surface Modification of Silica-Coated Fe3O4 Nanoparticles in the Structure and Enzyme Activity of Lysozyme

Surface-modified gold nanoparticles: A novel chemical probe for precise fluorescent detection of aluminium (Al3+) ions; investigating DFT insights and molecular logic gate behaviour

Trivalent metal cation fluorescence chemosensors are one of the most important areas of research because of their rarity. The necessity for easy-to-synthesize molecular chemosensors and to immobilize them on materials platform are enhancing continually. In this paper, we report the rapid sensing of Al3+ ion recognition by naphthalene derivative (N1) and tethered with gold nanoparticles (N1-AuNps). The cysteine-carrying naphthalene derivative is synthesized (Receptor-N1) and it forms a self-assembled monolayer on gold nanoparticles through the thiol moiety (N1-AuNPs). The structure of the synthesized receptor and the chemosensor assembled with AuNPs are characterized using spectroscopic and imaging techniques. On the gold nanoparticles, the surface-assembled compound highly selectively binds with Al3+ ion in the aqueous medium compared with a free receptor (N1). We present an improved colorimetric method that offers both high sensitivity and rapid detection for transition metal ions, specifically Al3+ ions. The determination of the binding stoichiometry and binding ratio between N1 / N1-AuNPs and Al3+ ion was achieved through the utilization of Jobs' plot and B-H plot which confirmed a 1:1 ratio. The binding phenomenon between N1-AuNPs and Al3+ ion has been ascertained to be predominantly according to the limited PET with CHEF impact technique. The N1-AuNPs chemosensor responds to H+ and Al3+ ions by demonstrating XOR molecular logic gate functionality and operating across a wide pH range. The nanoparticle-tethered chemosensor presents an effective system that can be employed in Al3+ ion sensing. The addition of Na2EDTA to the [N1-AuNPs - Al3+] complex solution caused a quenching of the fluorescence emission, which provides evidence of the reversible nature of the chemosensor. To gain further insights into the binding mode of Al3+ with N1-AuNPs, quantum mechanical investigations using density functional theory (TDDFT) have been conducted. We evaluated the effectiveness of our methodology for quantifying Al3+ ions in the water waste produced by significant industrial reactions.

Mechanistic analysis of transformative Pd/NHC catalyst evolution in the 1,2-diphenylacetylene semihydrogenation using molecular hydrogen

This study explored the dynamic transformations of the Pd/NHC catalytic system during the semihydrogenation of alkynes using molecular hydrogen under mild reaction conditions. Focusing on the appearance of a “cocktail”-type system, we harnessed advanced characterization methods, such as NMR, ESI-HRMS, and SEM/TEM. In the hydrogenation process of 1,2–diphenylacetylene, the Pd/NHC complex evolves to produce novel palladium-based compounds and a heterogeneous phase, which partially precipitates into catalytically active nanoparticles. A pivotal finding revealed that the modification of the Pd nanoparticle surface by organic ligands under reaction conditions significantly influenced the catalytic activity of the Pd particles. The split test results suggest an enhanced selectivity toward (Z)-stilbene when the precipitate is maintained in the reaction mixture, highlighting that the palladium nanoparticles act as active catalysts (or reservoirs of active species) synergistically with dissolved molecular complexes. This research reports important findings for understanding the dynamics of the Pd/NHC system, contributing to the development of more efficient catalytic systems.