Anticancer Activity of Au/CNT Nanocomposite Fabricated by Nanosecond Pulsed Laser Ablation Method on Colon and Cervical Cancer

Gold nanoparticles (AuNPs) and carbon nanotubes (CNTs) are increasingly being investigated for cancer management due to their physicochemical properties, low toxicity, and biocompatibility. This study used an eco-friendly technique (laser synthesis) to fabricate AuNP and Au/CNT nanocomposites. AuNPs, Au/CNTs, and CNTs were tested as potential cancer nanotherapeutics on colorectal carcinoma cells (HCT-116) and cervical cancer cells (HeLa) using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. In addition, the non-cancer embryonic kidney cells HEK-293 were taken as a control in the study. The cell viability assay demonstrated a significant reduction in cancer cell population post 48 h treatments of AuNPs, and Au/CNTs. The average cell viabilities of AuNPs, Au/CNTs, and CNTs for HCT-116 cells were 50.62%, 65.88%, 93.55%, and for HeLa cells, the cell viabilities were 50.88%, 66.51%, 91.73%. The cell viabilities for HEK-293 were 50.44%, 65.80%, 93.20%. Both AuNPs and Au/CNTs showed higher cell toxicity and cell death compared with CNT nanomaterials. The treatment of AuNPs and Au/CNTs showed strong inhibitory action on HCT-116 and HeLa cells. However, the treatment of CNTs did not significantly decrease HCT-116 and HeLa cells, and there was only a minor decrease. The treatment of AuNPs, and Au/CNTs, on normal HEK-293 cells also showed a significant decrease in cell viability, but the treatment of CNTs did not produce a significant decrease in the HEK-293 cells. This study shows that a simplified synthesis technique like laser synthesis for the preparation of high-purity nanomaterials has good efficacy for possible future cancer therapy with minimal toxicity.

Hairy silica nanosphere supported metal nanoparticles for reductive degradation of dye pollutants

Hairy materials can act as a sort of scaffold for the fabrication of functional hybrid composites. In this work, silica nanospheres modified with covalently grafted poly(4-vinylpyridine) (P4VP) brushes, namely, "hairy" silica spheres, were utilized as a support for the anchorage of metal nanoparticles (MNPs), thus resulting in the hierarchical SiO₂@P4VP/MNP structure. In this triple-phase boundary heteronanostructure, the SiO₂-supported MNPs are well stabilized by the P4VP matrix to avoid aggregation and leaching. These SiO₂@P4VP/MNP nanocomposites exhibit good catalytic activity in the reductive degradation of organic dyes, i.e., 4-nitrophenol and rhodamine B and possess excellent stability and recyclability for five successive cycles.

Facile Preparation and Enhanced Catalytic Properties of Self-Assembled Pd Nanoparticle-Loaded Nanocomposite Films Synthesized via the Electrospun Approach

In recent years, people pay more attention to environmental pollution and the treatment of sewage has become the focus of recent research. Palladium nanoparticles have good catalytic properties but are easy to agglomerate. Therefore, we used the electrospinning technology to prepare a uniform composite nanofiber film based on polyacrylic acid (PAA) and polyvinyl alcohol (PVA), which demonstrated that they are good carriers of palladium nanoparticles to make the nanoparticles well dispersed. Furthermore, carbon nanotubes (CNTs) were added to increase the specific surface area of the composite nanofiber film and improve its mechanical properties. The successfully synthesized PAA/PVA/CNT-COOH@palladium nanoparticle (PdNP) composite fiber films were characterized by scanning electron microscopy, transmission electron microscopy, and thermogravimetry analysis. p-Nitrophenol and 2-nitroaniline were utilized as typical pollutants to further evaluate the catalytic performance of PAA/PVA/CNT-COOH@PdNP composite fiber films. The PAA/PVA/CNT-COOH@PdNP composite fiber films exhibited enhanced catalytic performance and could be reused for eight consecutive cycles. This work provided new clues for the preparation and application of composite electrospun film materials.

Facile preparation of surfactant-free Au NPs/RGO/Ni foam for degradation of 4-nitrophenol and detection of hydrogen peroxide

The application of Au nanoparticles (Au NPs) often requires surface modification with chemical surfactants, which dramatically reduce the surface activity and increase the chemical contamination and cost of Au NPs. In this research, we have developed a novel Au NPs/reduced graphene oxide/Ni foam hybrid (Au NPs/RGO/NiF) by in situ reduction through ascorbic acid and replacement reaction. This method is green, facile and efficient. The Au NPs are free of chemical surfactants and are homogeneously distributed on the surface of the RGO/NiF. The as-prepared Au NPs/RGO/NiF hybrid is uniform, stable and exhibits not only a high reduction efficiency for the reduction of 4-nitrophenol with a catalytic kinetic constant of up to 0.46 min^-1 (0.15 cm³ catalysis) but also a sensitive and selective detection of H₂O₂ with a detection limit of ∼1.60 μM.

Highly efficient aqueous phase reduction of nitroarenes catalyzed by phosphine-decorated polymer immobilized ionic liquid stabilized PdNPs

Phosphino-decorated polymer immobilised ionic liquid-stabilised PdNPs are highly efficient catalysts for the aqueous phase hydrogenation and transfer hydrogenation of aromatic nitro compounds in batch and continuous flow.

Special Magnetic Catalyst with Lignin-Reduced Au-Pd Nanoalloy

This study describes a new strategy to fabricate a special magnetic catalyst via facile coating Au-Pd nanoalloy catalysts onto a commercial magnetic stirring bar, without the incorporation of iron element. First, the abundant natural "waste" lignin was utilized as the reducing and stabilizing agent to prepare Au-Pd nanoalloys in a green manner. The Au-Pd nanoalloys were assumed to have a core-shell structure with an Au-rich core and a Pd-rich shell. The Au-Pd nanoalloys could be well dispersed in aqueous medium due to the stabilizing effect of lignin and be conveniently coated onto the surface of a commercial stirring bar. The Au_1.0Pd_1.0 nanoalloy catalyst exhibited excellent catalytic activities in the reduction of 4-nitrophenol to 4-amnophenol by NaBH₄, with a rate constant (k) of 0.239 min^-1, which was higher than that of Au_0.5Pd_1.0 and Au_2.0Pd_1.0 nanoalloys and 4 times higher than that of a single-component Au or Pd nanoparticles. Besides, the catalytic ability of Au-Pd nanoalloy catalyst could be maintained even after seven cycles of catalysis. The catalytic rate constant was found to be positively correlated to the stirring speed of the bar. The scanning electron microscopy analysis revealed ravines and pores on the surface of lignin-nanoalloys composites, implying the possible mechanism of the catalytic activities. This study not only proved the feasibility of lignin for green synthesis of Au-Pd nanoalloys but also proposed a facile and innovated strategy for the future production of solid/liquid catalytic platforms where the developed method could be used to coat any surface interfacing the reagents.

Multi-functionalized herringbone carbon nanofiber for anodes of lithium ion batteries

Herringbone carbon nanofibers (HCNFs) are prepared for use as anode materials in lithium-ion batteries (LIBs). HCNFs are prepared using a Ni-Fe catalyst and subsequently multi-functionalized with oxygen using the Hummers' method, and then with both oxygen and nitrogen-containing 2-ureido-4[1H]pyrimidinone (UHP) moieties, which endow the HCNFs with the ability to form quadruple hydrogen bonds (QHBs). The as-prepared HCNFs are, on average, 13 μm in length and 100 nm in diameter, with a highly graphitic structure. The oxidized HCNFs (Ox-HCNFs) obtained by Hummers' method are partially exfoliated, having double-bladed saw-like structures that extend in the direction of the graphite planes. QHBs are formed between the HCNFs after functionalization with the UHP moieties. The final surface-modified HCNFs (N-Ox-HCNFs) have more electrochemical sites, shorter Li⁺ diffusion lengths, and additional electron pathways compared with the as-prepared HCNF and Ox-HCNF. The introduction of oxygen- and nitrogen-containing functional groups improves the performance of LIBs: a high charge capacity of 763 mA h g^-1 at 0.1 A g^-1, excellent rate capability (a capacity of 402 mA h g^-1 at 3 A g^-1), and near 100% capacity retention after 300 cycles are reported.

ZnO nanosheet-assisted immobilization of Ag nanoparticles on graphene/Ni foam for highly efficient reduction of 4-nitrophenol

ZnO nanosheet-assisted immobilization of Ag nanoparticles on graphene/Ni foam forming a novel hybrid structure for catalysis.

Porous gold nanoparticle/graphene oxide composite as efficient catalysts for reduction of 4-nitrophenol

Porous gold nanoparticle/graphene oxide composites obtained through freeze-drying method show superior continuous catalytic performance in the reduction of 4-nitrophenol.

Amorphous NiB/carbon nanohybrids: synthesis and catalytic enhancement induced by electron transfer

Amorphous NiB/C shows synergistic catalysis for 4-nitrophenol reduction, induced by the electron transfer from NiB alloy to carbon support.

Controllable synthesis of a Pd/PdO nanocomposite as a catalyst for hydrogenation of nitroarenes to anilines in water

The different Pd/PdO ratios nanoparticles supported on oxide carbon nanotubes can be controllable synthesized by a one-pot gas–liquid interfacial plasma method, which can catalyze the hydrogenation of nitroarenes in water by atmosphere pressure H₂.

Graphene oxide/carbon nanotubes–Fe3O4 supported Pd nanoparticles for hydrogenation of nitroarenes and C–H activation

The GO/CNT–Fe₃O₄ support Pd nanoparticles are synthesized by the gas–liquid interfacial plasma method. The catalysts exhibit remarkable catalytic activity during the hydrogenation of nitroarenes and C–H functionalization.

Controllable synthesis of graphene oxide–silver (gold) nanocomposites and their size-dependencies

The Raman scattering properties and catalytic activities of as-synthesized GO–metal composites were correlated with the size of metallic nanoparticles and exhibited size-dependent behavior.

Self-assembly of cuprous oxide nanoparticles supported on reduced graphene oxide and their enhanced performance for catalytic reduction of nitrophenols

Mechanism for the catalytic reduction of nitrophenols; the catalyst can be reused with nearly invariable high catalytic efficiency.

Biogenic gold nanoparticles-reduced graphene oxide nanohybrid: synthesis, characterization and application in chemical and biological reduction of nitroaromatics

The biogenic AuNPs/rGO can participate in and accelerate electron transfer, and catalyze both chemical and biological reduction of nitroaromatics efficiently.