Incorporation Of Metal Nanoparticles Research Articles

Promotion of Probabilistic Bit Generation in Mott Devices by Embedded Metal Nanoparticles.

Considerable attention has been drawn to the use of volatile two-terminal devices relying on the Mott transition for the stochastic generation of probabilistic bits (p-bits) in emerging probabilistic computing. To improve randomness and endurance of bit streams provided by these devices, delicate control of the transient evolution of switchable domains is required to enhance stochastic p-bit generation. Herein, it is demonstrated that the randomness of p-bit streams generated via the consecutive pulse inputs of pump-probe protocols can be increased by the deliberate incorporation of metal nanoparticles (NPs), which influence the transient dynamics of the nanoscale metallic phase in VO2 Mott switches. Among the vertically stacked Pt-NP-containing VO2 threshold switches, those with higher Pt NP density show a considerably wider range of p-bit operation (e.g., up to ≈300% increase in ΔVprobe upon going from (Pt NP/VO2)0 to (Pt NP/VO2)11) and can therefore be operated under the conditions of high speed (400 kbit s-1), low power consumption (14 nJ per bit), and high stability (>105200 bits) for p-bit generation. Thus, the study presents a novel strategy that exploits nanoscale phase control to maximize the generation of nondeterministic information sources for energy-efficient probabilistic computing hardware.

Synergistic effects of TiO2-ZnO/Poly(methyl methacrylate) nanocomposite films: Enhanced wettability, antimicrobial activity, and biocompatibility

The poly (methyl methacrylate) (PMMA) nanocomposite films were fabricated using a cost-effective solvent evaporation method. The dominance of the wurtzite Zinc oxide (ZnO) phase was observed, accompanied by a suppression in the phase intensity of anatase titanium dioxide (TiO2) in the PMMA matrix confirmed by the XRD. New peaks appeared at 1651 cm−1 for the Ti-OH of TiO2 and 590 cm−1 for the metal–oxygen vibration of ZnO in the nanocomposite films. SEM micrograph of the TZPMMA resulted in the formation of nanopores with the nanoparticles embedded in the PMMA matrix. The wettability was enhanced by 23 % with the incorporation of metallic nanoparticles. Zinc ions increased antimicrobial susceptibility against S. aureus by 20 % more than E. coli, demonstrating the potential for fighting bacterial infections. The porous surface created by the nanoparticles improved the cell viability of the PMMA. Zebrafish embryo mortality percentage (0.5 %) and cell viability percentage (80 %) against human gingival fibroblasts (hGFs) showed that the incorporation of metal oxides made the PMMA, a potential candidate for biomedical applications.

Remarkably enhancing dielectric permittivity and suppressing loss of PVDF via incorporating metal nanoparticles decorated glass fibers

Dielectrics with high permittivity and low dielectric loss have so far received considerable attention because of their wide applications in various electronic devices. However, the enhanced permittivity of dielectrics is always accompanied by an increase in loss. In this work, targeting at enhancing the permittivity of poly(vinylidene fluoride) (PVDF) without elevating loss, gold nanoparticles (Au NPs) decorated glass fibers (GF) are incorporated into the PVDF, forming a unique design of Au@GF/PVDF composites. The effects of gold nanoparticle content, calcination temperature, and hot-pressing pressure on the dielectric properties are studied. Interestingly, for the composite with gold sputtering time of 3 min, a remarkable dielectric enhancement of 430% (i.e. from 7.8 to 33.5 at 10 kHz) along with an obvious loss suppression of 56% (i.e. from 0.0353 to 0.0198) are concurrently achieved. It is believed that, the increase in permittivity is mainly attributed to the Maxwell–Wagner–Sillars effect of effective micro-capacitors and cluster polarization of gold nanoparticles while the suppressed loss is originated from the intrinsic low loss of GF and the Coulomb-blockade effect of gold nanoparticles. This work offers a promising strategy to simultaneously enhance the permittivity and suppress the loss of dielectric materials.

Using Ag nanoparticles in the electron transport layer of perovskite solar cells to improve efficiency

The incorporation of metal nanoparticles within various types of photovoltaic technologies has been shown to increase the performance of organic solar cells, dye sensitized solar cells, and more recently perovskite solar cells. Using this type of nanostructured composite transport layer could help improve the efficiency and stability of perovskite solar cells whilst avoiding the use of dopants that can damage the perovskite layer. In this work, Ag nanoparticles are synthesized and used to form a SnO2:Ag nanoparticle composite transport layer for the first time. On its own, SnO2 is in one of the most efficient transport layers for perovskite solar cells. Upon inclusion of the Ag nanoparticles the recombination rate is increased (detrimental for device performance) as shown by impedance spectroscopy, and the charge carrier transfer and extraction is enhanced (beneficial for device performance) as shown by photoluminescence measurements. In order to balance these opposing factors, the nanoparticle concentration was optimized at an intermediate concentration with a corresponding power conversion efficiency increase from 13.4 ± 0.7 % for reference solar cells without nanoparticles to 14.3 ± 0.3 % for those with nanoparticles. These devices are one of the first examples of, and exhibit the highest reported efficiency for, perovskite solar cells fabricated completely in air with nanocomposite oxide layers. The protocol developed and reported here to improve the nanocomposite transport layer has general applicability in other fields, including LEDs, FETs, and electronic devices where transparency and conductivity are also required.

Advancements in Enhancing Antibacterial Properties of Cotton Fabric through Chitosan and Nanoparticles

AbstractOver recent years, the garment industry has been actively seeking innovative solutions to address critical challenges in clothing production. One significant issue has been the susceptibility of hydrophilic cotton fabrics, commonly used in healthcare and sportswear, to bacterial growth, posing hygiene concerns. To deal with this, it becomes crucial for us to make durable cotton fabrics that can fight bacteria. This study explores the development of durable antibacterial cotton textiles by utilizing a range of antibacterial agents and mechanisms. Chitosan's properties, such as its ability to inhibit fungal growth, compatibility, non‐toxicity, bioactivity, and antimicrobial potential make it a promising candidate for the textile industry. Additionally, the incorporation of metal nanoparticles along with chitosan offers interesting potential, such as UV absorption, self‐cleaning capabilities, and antimicrobial activity. Therefore, research aimed at enhancing cotton fabric by harnessing the potential of chitosan and metal nanoparticles continues to attract significant attention in today's textile world. Cotton fabric modified by combining chitosan and nanoparticles exhibits high antimicrobial activity compared to fabric modified with either nanoparticles or chitosan alone. The implications of this study are far‐reaching with improvement in hygiene, comfort, and durability in a wide range of clothing applications, thus making a substantial contribution to the evolution of the textile industry.

Incorporating metal nanoparticles in porous materials via selective heating effect using microwave

Incorporating metal nanoparticles in porous materials via selective heating effect using microwave

Paper-Derived Carbon Electrodes, a Versatile Option to Develop Electrochemical Sensors

Carbon-based materials are particularly well-suited for electroanalytical applications due to their distinct properties, such as high chemical stability, large electroactive areas, wide electrochemical potential window in aqueous solutions, low electrical resistance, rich surface chemistry, and activity towards a variety of redox reactions. While carbon electrodes can be produced via thermal decomposition of gaseous hydrocarbons followed by their surface-induced recombination, this method is not cost-effective and suffers from both low efficiency (~20%) and limited selectivity towards graphitic forms. Alternatively, carbon electrodes can be developed via pyrolytic treatment of non-volatile substrates. This approach yields carbon materials that are rich in graphitic phases and provides researchers a much richer selection of starting materials and source-to-product efficiencies ~70%. Our team has applied this approach to develop several optically transparent carbon electrodes and has described a method for fabricating carbon electrodes by pyrolysis of paper, using a tube furnace and under a mild reducing atmosphere. The resulting electrodes not only feature the properties of traditional carbon materials but also preserve the 3D structure of the starting material, are mildly hydrophobic, and offer a wide electrochemical window and can be patterned using laser engraving. Moreover, the process also enables the incorporation of metallic nanoparticles within the structure of the material (by pyrolyzing paper pre-soaked in a solution containing the selected cation), significantly improving the conductivity of the material. Thus, this presentation will provide a brief summary of the reactions leading to the fabrication of these substrates as well as discuss the most recent applications towards their use as sensors in microfluidic devices.Special emphasis will be placed on the use of these electrodes for the detection of S. aureus, application that required the modification of the material with a thin layer of sputtered gold (that minimizes lateral resistivity and significantly improves the electron transfer process) and with chitosan (used as a binder to offer flexibility). This biosensor was controlled using a custom-built potentiostat (via a wireless connection), which was used to detect the presence of the bacteria via the oxidation of the ferrocyanide (produced by the bacteria’s respiration cycle) in the presence of mannitol.More information about the group can be found in our web site scienceweb.clemson.edu/uacl/

Immobilizing Metal Nanoparticles on Hierarchically Porous Organic Cages with Size Control for Enhanced Catalysis

Incorporating metal nanoparticles (MNPs) into porous composites with controlled size and spatial distributions is beneficial for a broad range of applications, but it remains a synthetic challenge. Here, we present a method to immobilize a series of highly dispersed MNPs (Pd, Ir, Pt, Rh, and Ru) with controlled size (<2 nm) on hierarchically micro- and mesoporous organic cage supports. Specifically, the metal-ionic surfactant complexes serve as both metal precursors and mesopore-forming agents during self-assembly with a microporous imine cage CC3, resulting in a uniform distribution of metal precursors across the resultant supports. The functional heads on the ionic surfactants as binding sites, together with the nanoconfinement of pores, guide the nucleation and growth of MNPs and prevent their agglomeration after chemical reduction. Moreover, the as-synthesized Pd NPs exhibit remarkable activity and selectivity in the tandem reaction due to the advantages of ultrasmall particle size and improved mass diffusion facilitated by the hierarchical pores.

Thermally‐controlled spherical peptide gel architectures prepared using the pH switch method

AbstractSelf‐assembling nanostructured peptide gels are promising materials for sensing, drug delivery, and energy harvesting. Of particular interest are short diphenylalanine (FF) peptides modified with 9‐fluorenylmethyloxycarbonyl (Fmoc), which promotes the association of the peptide building blocks. Fmoc‐FF gels generally form fibrous networks and while other structures have been demonstrated, further control of the gelation and resulting ordered three‐dimensional structures potentially offers new possibilities in tissue engineering, sensing, and drug release applications. Herein, we report that the structure tunability of Fmoc‐FF gels can be achieved by controlling the water content and the temperature. We further explore the incorporation of metal nanoparticles in the formation of the gel to enable optical sensing applications based on hybrid Fmoc‐FF‐nanoparticle microspheres. Finally, fluorescence lifetime imaging microscopy reveals a correlation between lifetime and reduced bandgap, in support of a semiconductor‐induced charge transfer mechanism that might also increase the stability of an excited state of a probe molecule. The observations potentially further widen the use of these peptide materials in bioimaging and sensing applications.

Highly active and stable catalysts for Baeyer–Villiger oxidation – Traditional postloading vs in situ synthesis of Fe/N/C nanoparticles

Nitrogen-doped carbon composites are prepared using simple precursors, such as glucose or urea and used as supports for Fe nanoparticles. The present work investigated two approaches for incorporating metal nanoparticles into the composite: traditional metal postloading and in situ formation of a metal/N-doped carbon catalyst. The impacts of the preparation technique on (i) the characteristics of the resulting iron oxides (Fe2O3 and Fe3O4) and (ii) the nanoparticle distribution on the support were determined. Microscopic surface characterization revealed that the postloading method promoted a uniform distribution of Fe nanoparticles (5–10 nm), which enhanced the activity and long-term stability of the catalytic system for the Baeyer–Villiger oxidation of cyclic ketones. The product yield reached 97% (5 h, 60 °C), and after the third reaction cycle, the yield remained at 96%. The proposed synthetic approach for preparing active and stable catalysts provides a new perspective for the inexpensive and sustainable synthesis of lactones.

Laser induced breakdown spectroscopy of aluminum incorporated with metallic nanoparticles

Laser-Induced Breakdown Spectroscopy is a promising spectroscopic technique with a vast spectrum of applications in fields concerned with identification and detection of elements. But it faces some limitations due to self-absorption, noise due to matrix effect and line broadening resulting in low emission signal. This research proposes LIBS signal enhancement by incorporation of metal nanoparticles (Cu, Mg, Au) on Al surface and compares their effect. The successful optical emissions enhancement is achieved as the emission intensities of Al- and Na- lines of three coated samples are compared with those of uncoated Al. The Electron Temperature has been evaluated by Boltzmann plot and an increase in Electron Temperature has been observed with the incorporation of nanoparticles to the aluminum surface as compared to the untreated aluminum, due to more plasma emissions. The Electron Number Density of the aluminum plasma did not have much effect with the incorporation of Nanoparticles. The Local Thermal Equilibrium condition has been satisfied and checked by Mc Whirter’s Criterion. The incorporation of metal nanoparticles can be declared as an effective method not only for LIBS signal enhancement but also better detection of trace elements which were not observed without the use of Nanoparticles.

The effects of metal nanoparticles incorporation on the mechanical properties of denture base acrylic resin.

The aim of this study was to examine the flexural strength of acrylic resin base material incorporated with iron, copper, and titanium nanoparticles. Seventy bars of samples (65x10x2.5 mm3) were divided into seven groups. Acrylic samples were prepared according to the manufacturer's instructions. Fe2O3, CuO and TiO2 nanoparticles were manually added in a proportion of 1wt% and 3wt% to the heat-polymerized acrylic resin. The Universal Testing Machine was used for 3-point flexural test of 5 mm/min force. ANOVA and Weibull analyses were used for the statistical analyses. A statistical difference was found between the nanoparticle-added group and the control group. The highest mean value was observed for the 1wt% TiO2 added group, (84.99 MPa) and the lowest value was for the 3wt% CuO added group (71.32 MPa) (p<0,001). The 3wt% Fe2O3 and CuO added groups showed lower values than the control group. The incorporation of TiO2 nanoparticles into acrylic resin in a proportion of 1wt% increased the flexural strength values of the resins. Within the limitations, the nanoparticle addition to acrylic resins could improve the mechanical properties; however, when the percentage of nanoparticle addition increases, the flexural strength values of the acrylic resins decrease.

(Keynote) Mechanistic Understanding of the Activity of Atomically Dispersed Transition Metal-Nitrogen-Carbon Catalysts in Oxygen, Carbon Dioxide or Nitrogen Electro-Reduction

Over the last two decades, platinum group metal-free (PGM-free) catalysts are attracting increasing attention and finding applications in several important process across many electrochemical energy technologies. Among those PGM-free materials, atomically dispersed (AD) transition metal-nitrogen-carbon (M-N-C) catalysts are gaining exceptional popularity as they demonstrate very high (for this class of materials) activity in oxygen reduction reaction (ORR)1 and are the only cathode catalysts suitable for both proton exchange membrane fuel cells (PEMFC) and alkaline, including anion/hydroxyl exchange membrane fuel cells (AFC, AEMFC/HEMFC). Over the last few years, M-N-C catalysts have shown promising activity in carbon dioxide reduction reaction (CO2RR).2 In this case, varying the transition metal in M-N-Cs opens routes for controlling the selectivity towards a list of C1 and C2 products. There are recent reports on catalytic activity of AD M-N-C materials in direct electro-reduction of molecular nitrogen (N2RR) or reactions of reduction of nitrates, nitrites or various nitrogen oxides (NOx). We have systematically investigated all these processes having as a base the M-N-C catalysts synthesized by sacrificial support method (SSM) – a hard template approach with transition metal salt and charge-transfer organic salt (nicarbazin) mixed by ball-milling, pyrolyzed at high temperature in inert atmosphere and then etched in HF after cooling. In most cases a secondary (similar) pyrolysis was performed to refine the material and ensure its AD character.The makeup and structure of the active site/sites of the AD M-N0C electrocatalysts, including geometry (coordination) and chemistry (composition and oxidation state) remain contentious to this day. There is an emerging agreement however, that the transition metal (at least for the 2nd row transitions meals) is immediately associated with (liganded by) the nitrogen functionalities, displayed on the surface if the carbonaceous substrate. It is almost universally accepted that N-coordinated AD transition metal ions, either as in-plane or edge-type defect in “graphene” sheet, are the main/principal active sites. This is often combined with a broadly accepted hypothesis that micro-porous surface area plays a critical role forming edge-type, intercalational active sites while meso-porous interface is most-likely associated with the in-plane, substitutional AD metal sites. Candidate structures participating in reativity towards O2, CO2 or nitrogen species include a list of nitrogen-containg and oxygen-containng moeties in the carbonaceous matrix. The carbon itself displays various degrees of graphitization, depending on the transition metal used in M-N-C synthesis. Additional complexity in this calss of caralysts study comes from the fact that many samples are not strictly AD materials. They often contain incorporated metal nano-particles, corresponding (native) oxides and/or carbides and nitrides (oxocabides and oxonitrides have been observed as well).These “unrefined” M-N-C materials are often used in practice and the corresponding nano-particle components of the de-facto nanocomposites do alter substantially the reactivity and selectivity of the catalysts in all these electro-reduction reactions.This talk discusses the mechanistic aspects of M-N-C catalysts in ORR, CO2RR, N2RR and electroreduction of nitrogen-containing oxo-species, obtained when cross-referencing electrochemical activity results obtained in rotating disk and rotating ring-disk electrodes setting (RDE/RRDE) with those observed in near-ambient pressure X-ray photo-electron spectroscopy (NAP-XPS) and supported by density functional theory calculations of the reagents adsorption on AD transition metal or nitrogen- or oxygen-containing moieties from the carbonaceous matrix of the M-N-Cs. The later are of particular importance as significant reactivity has been observed for most of those processes when metal-free, nitrogen-doped carbon (N-C) catalysts are used.3 We will present a case that outlines the reactivity of M-N-C in those important electro-reduction reactions in terms of (i) role of the AD transition metal, (ii) role of the surface N-groups as co-catalysts/alternative sites (iii) role of surface oxides as co-catalysts or hydrophilic/hydrophobic properties descriptor, the last being also critically dependent on morphology.4

Optimization of metal nanoparticles concentration in dye solution to enhance performance of dye sensitized solar cells

In this study, we incorporate metal nanoparticles of AuNP and AgNP into dye N-719 solution in order to enhance the light absorption of dye-sensitized solar cells (DSSCs) device. AuNP or AgNP was mixed into N-719 dye solution by optimized the concentration of metal NPs. The optical property of the mixtures was investigated by use of UV-Vis spectroscopy while the morphology of the solutions was captured by TEM microscopy. The performance of DSSCs was done by J-V measurement equipped with solar simulator under light illumination of 100mW/cm2. Our fabricated DSSC devices show the enhancement of current density and power conversion efficiency (PCE) with the incorporation of metal NPs into dye layer. Addition of gold nanoparticle capped by dodecanethiols (AuDT) 5.66 wt.% reveals the enhancement of PCE devices from 1.58% without AuDT as reference to 2.77% with AuDT. Similar case for the addition of AgSC8 into dye of DSSC gives the same tendencies.

Silver-Nanoparticle-Assisted Modulation of NH3 Desorption on MIL-101.

Ammonia has recently emerged as a promising hydrogen carrier for renewable energy conversion. Establishing a better understanding and control of ammonia adsorption and desorption is necessary to improve future energy generation. Metal–organic frameworks (MOFs) have shown improved ammonia capacity and stability over conventional adsorbents such as silica and zeolite. However, ammonia desorption requires high temperature over 150 °C, which is not desirable for energy-efficient ammonia reuse and recycling. Here, we loaded silver nanoparticles from 6.6 to 51.4 wt% in MIL-101 (Ag@MIL-101) using an impregnation method to develop an efficient MOF-based hybrid adsorbent for ammonia uptake. The incorporation of metal nanoparticles into MIL-101 has not been widely explored for ammonia uptake, even though such hybrid nanostructures have significantly enhanced catalytic activities and gas sensing capacities. Structural features of Ag@MIL-101 with different Ag wt% were examined using transmission electron microscopy, X-ray powder diffraction, and infrared spectroscopy, demonstrating successful formation of silver nanoparticles in MIL-101. Ag@MIL-101 (6.6 wt%) showed hysteresis in the N2 isotherm and an increase in the fraction of larger pores, indicating that mesopores were generated during the impregnation. Temperature-programmed desorption with ammonia was performed to understand the binding affinity of ammonia molecules on Ag@MIL-101. The binding affinity was the lowest with Ag@MIL-101 (6.6 wt%), including the largest relative fraction in the amount of desorbed ammonia molecules. It was presumed that cooperative interaction between the silver nanoparticle and the MIL-101 framework for ammonia molecules could allow such a decrease in the desorption temperature. Our design strategy with metal nanoparticles incorporated into MOFs would contribute to develop hybrid MOFs that reduce energy consumption when reusing ammonia from storage.

Recent Advances in Complete Methane Oxidation using Zeolite‐Supported Metal Nanoparticle Catalysts

AbstractThe high fuel efficiency of natural gas makes it an attractive alternative to coal and oil during the transition towards renewable energy resources. Natural gas engines are needed to ensure a stable power grid that can accommodate fluctuations in renewable energy production. Unfortunately, these engines emit as much as 3–4 % of the methane (CH4) in the natural gas under learn‐burn conditions. This methane slip has a high environmental cost since CH4 is a potent greenhouse gas. Complete catalytic oxidation of CH4 can potentially control the emission. Unfortunately, the best performing Pd/Al2O3 catalysts suffer from severe deactivation under operating conditions. After decades of little progress, zeolite‐supported catalysts have recently attracted increased attention. Here, we review the current status, challenges, and prospects for controlling methane emissions from large engines using zeolite‐based catalysts. The determining factors for catalytic activity and stability are the zeolite topology, alumina content, counter‐ion, and active metal nanoparticles incorporation. In addition, we highlight the importance of testing under realistic operation conditions. Thus, the review provides a framework for developing a catalyst technology critically needed to fulfill the Paris Climate Agreement.

Nanotechnology and Conventional Techniques to Detect Latent Fingerprints on Surfaces

Abstract: This review paper centers around the use of legal science in dormant unique mark identification by the utilization of particular nanomaterials and their advantages concerning the nature of finger impression pictures. The use of measurable science in the discovery of the idle unique finger impression The benefits and significant aftereffects of studies directed on inert finger impression recognition with different nanomaterials which incorporate metal nano-particles, metallic oxide nanoparticles, semiconductor quantum specks, carbon dabs, polymer dabs, fluorescent silica nanoparticles, fluorescent mesoporous silica nanoparticles, fluorescent silica nanoparticles, formed polyelectrolyte spots, accumulation prompted outflow brilliant atom joined nanomaterials and phenomenal earth fluorescence nanoparticles are basically talked about. A portion of the nanomaterials utilized for idle finger impression discovery didn't bring about great quality finger impression pictures and these detriments are featured. Keywords: Nanotechnology, Nanomaterials, latent fingerprint, fluorescence

Polysaccharides and Metal Nanoparticles for Functional Textiles: A Review.

Nanotechnology is a powerful tool for engineering functional materials that has the potential to transform textiles into high-performance, value-added products. In recent years, there has been considerable interest in the development of functional textiles using metal nanoparticles (MNPs). The incorporation of MNPs in textiles allows for the obtention of multifunctional properties, such as ultraviolet (UV) protection, self-cleaning, and electrical conductivity, as well as antimicrobial, antistatic, antiwrinkle, and flame retardant properties, without compromising the inherent characteristics of the textile. Environmental sustainability is also one of the main motivations in development and innovation in the textile industry. Thus, the synthesis of MNPs using ecofriendly sources, such as polysaccharides, is of high importance. The main functions of polysaccharides in these processes are the reduction and stabilization of MNPs, as well as the adhesion of MNPs onto fabrics. This review covers the major research attempts to obtain textiles with different functional properties using polysaccharides and MNPs. The main polysaccharides reported include chitosan, alginate, starch, cyclodextrins, and cellulose, with silver, zinc, copper, and titanium being the most explored MNPs. The potential applications of these functionalized textiles are also reported, and they include healthcare (wound dressing, drug release), protection (antimicrobial activity, UV protection, flame retardant), and environmental remediation (catalysts).

The Infiltration of Silver Nanoparticles into Porous Silicon for Improving the Performance of Photonic Devices.

Hybrid nanostructures have a great potential to improve the overall properties of photonic devices. In the present study, silver nanoparticles (AgNPs) were infiltrated into nanostructured porous silicon (PSi) layers, aiming at enhancing the optoelectronic performance of Si-based devices. More specifically, Schottky diodes with three different configurations were fabricated, using Al/Si/Au as the basic structure. This structure was modified by adding PSi and PSi + AgNPs layers. Their characteristic electrical parameters were accurately determined by fitting the current–voltage curves to the non-ideal diode equation. Furthermore, electrochemical impedance spectroscopy was used to determine the electrical parameters of the diodes in a wide frequency range by fitting the Nyquist plots to the appropriate equivalent circuit model. The experimental results show a remarkable enhancement in electrical conduction after the incorporation of metallic nanoparticles. Moreover, the spectral photoresponse was examined for various devices. An approximately 10-fold increment in photoresponse was observed after the addition of Ag nanoparticles to the porous structures.

Assessment of the Biological Activities of Egyptian Purslane (Portulaca oleracea) Extract after Incorporating Metal Nanoparticles, in Vitro and in Vivo Study

Objective: Egyptian Purslane (Portulaca oleracea) is rich in omega-3 fatty acids and a wide range of vitamins and phyto-constituents that were absorbed slowly due to their high molecular weights. Therefore, this study was designed to accelerate the absorption of these phyto-constituents and hence increase their bioavailability by incorporating silver (Ag-NPs) and zinc oxide nanoparticles (ZnO-NPs) due to their impressive properties. Methods: The major phyto-constituents and different biological activities were quantified in aqueous extract before and after incorporating metal nanoparticles (M-NPs). The efficiency of ZnO-P. nano-extract was studied on cell cycle and apoptosis of human hepatocellular carcinoma (HEPG-2) cells. Then, both Ag- and ZnO-P. nano-extracts were studied against hepatic fibrosis induced by thioacetamide (TAA) in rats through undergoing different hematological and biochemical measurements in addition to the histopathological examination in hepatic tissues compared to the extract itself. Results: The ZnO-P. nano-extract showed significantly (P<0.05) higher antioxidant and scavenging activity due to the existence of higher total polyphenolic content. Also, it exhibited a significantly (P<0.05) higher inhibitory effect on acetyl cholinesterase (AChE) activity and higher cytotoxic activity against HEPG-2 cells. Therefore, ZnO-P. nano-extract was studied against the cell cycle and apoptosis of HEPG-2 cells compared to the extract itself. It was found that ZnO-P. nano-extract was safer than Ag-P. nano-extract. Both Ag- and ZnO- P. nano-extracts were studied against the hepatic fibrosis induced by thioacetamide (TAA) compared to the native extract. It was noticed that ZnO-P. nano-extract exhibited an ameliorative effect against hepatic fibrosis by decreasing levels of inflammatory and fibrotic markers significantly (P<0.05) more than Ag-P. nano-extract. Furthermore, it improved the antioxidant status of the hepatic tissue in addition to restoring the histopathological architecture of liver tissue. Conclusion: ZnO-P. nano-extract showed higher in vitro and in vivo biological activities than Ag-P. nano-extract and native P. extract itself.