Displaying publications 41 - 60 of 671 in total

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  1. Fulltext Heat and mass transfer on MHD squeezing flow of Jeffrey nanofluid in horizontal channel through permeable medium
    Mat Noor NA, Shafie S, Admon MA
    PLoS One, 2021;16(5):e0250402.
    PMID: 33956793 DOI: 10.1371/journal.pone.0250402
    The heat and mass transfer on time dependent hydrodynamic squeeze flow of Jeffrey nanofluid across two plates over permeable medium in the slip condition with heat generation/absorption, thermal radiation and chemical reaction are investigated. The impacts of Brownian motion and thermophoresis is examined in the Buongiorno's nanofluid model. Conversion of the governing partial differential equations to the ordinary differential equations is conducted via similarity transformation. The dimensionless equations are solved by imposing numerical method of Keller-box. The outputs are compared with previous reported works in the journals for the validation of the present outputs and found in proper agreement. The behavior of velocity, temperature, and nanoparticles concentration profiles by varying the pertinent parameters are examined. Findings portray that the acceleration of the velocity profile and the wall shear stress is due to the squeezing of plates. Furthermore, the velocity, temperature and concentration profile decline with boost in Hartmann number and ratio of relaxation to retardation times. It is discovered that the rate of heat transfer and temperature profile increase when viscous dissipation, thermophoresis and heat source/sink rises. In contrast, the increment of thermal radiation reduces the temperature and enhances the heat transfer rate. Besides, the mass transfer rate decelerates for increasing Brownian motion in nanofluid, while it elevates when chemical reaction and thermophoresis increases.
    Matched MeSH terms: Nanoparticles/chemistry
  2. Acaricidal, larvacidal, and repellent activity of Linalool loaded zinc oxide nanoparticles against Hyalomma anatolicum
    Alasmari SM, Albalawi AE, Alghabban AJ, Shater AF, Al-Ahmadi BM, Baghdadi HBA, et al.
    Trop Biomed, 2024 Sep 01;41(3):377-384.
    PMID: 39548793 DOI: 10.47665/tb.41.3.019
    Current strategies for tick control have led to the development of resistance and environmental contamination. Consequently, there is an urgent need for research into new and effective acaricides for tick control. The aim of this study was to fabricate and characterize Linalool loaded zinc oxide nanoparticles (Lin@ZNP), and to assess the acaricidal, larvacidal, and repellent activities of Lin@ ZNP against Hyalomma anatolicum, a prevalent tick species infesting cattle in Saudi Arabia. Lin@ ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The adult immersion, the larval packet, and the assessment of vertical movement behavior of tick larvae assays were utilized to examine the acaricidal, larvicidal, and repellent activities of Lin@ZNP against H. anatolicum, respectively. Furthermore, the impact of Lin@ZNP on acetylcholinesterase and oxidant/antioxidant enzyme activities was investigated. Exposure of adult H. anatolicum to different concentrations of Lin@ZNP resulted in noticeable (p<0.001) reductions in the viability rate of adults and the mean number, weight, and hatchability of eggs, compared to the control group. Lin@ZNP demonstrated significant repellent effects on H. anatolicum larvae after 60, 120, and 180 minutes of exposure. Lin@ZNP, particularly at all concentrations, markedly suppressed the acetylcholinesterase activity of the larval stage of H. anatolicum (P<0.001); but increase in malondialdehyde (MDA) levels (P<0.001) and a decrease in glutathione-S-transferase (GST) levels in H. anatolicum larvae (P<0.001). Lin@ZNP exhibited considerable acaricidal, larvicidal, and repellent effects against H. dromedarii adults and larvae in a manner dependent on the dosage. Additionally, Lin@ZNP notably reduced AChE levels and antioxidant activity, while inducing oxidative stress in H. anatolicum larvae. Nevertheless, further research is necessary to elucidate the precise mechanisms and practical efficacy of Lin@ZNP.
    Matched MeSH terms: Nanoparticles/chemistry
  3. Ultrasound-assisted fabrication of chitosan-hydroxypropyl methylcellulose nanoemulsions loaded with thymol and cinnamaldehyde: Physicochemical properties, stability, and antifungal activity
    Phyo HM, Al-Maqtari QA, Mi S, Du Y, Khalid MU, Yao W
    Int J Biol Macromol, 2024 Nov;281(Pt 1):136278.
    PMID: 39368575 DOI: 10.1016/j.ijbiomac.2024.136278
    This study investigated the influence of chitosan (CH) and hydroxypropyl methylcellulose (H), along with ultrasound power, on the physicochemical properties, antifungal activity, and stability of oil-in-water (O/W) nanoemulsions containing thymol and cinnamaldehyde in a 7:3 (v/v) ratio. Eight O/W formulations were prepared using CH, H, and a 1:1 (v/v) blend of CH and H, both with and without ultrasonication (U). Compared to untreated samples, U-treated nanoemulsions had lower droplet sizes (433-301 nm), polydispersity index (0.42-0.47), and zeta potential (-0.42-0.77 mV). The U treatment decreased L* and b* values, increased a* color attribute values, and increased apparent viscosity (0.26-2.17) at the same shear rate. After 28 days, microbiological testing of nanoemulsions treated with U showed counts below the detection limits (< 2 log CFU mL-1). The U-treated nanoemulsions exhibited stronger antifungal effects against R. stolonifer, with the NE/CH-U and NE/CH-H-U formulations demonstrating the lowest minimum inhibitory and fungicidal concentrations, measured at 0.12 and 0.24 μL/mL, respectively. On day 28, U-treated nanoemulsions demonstrated higher ionic, thermal, and physical stability than untreated samples. These findings suggest that the stability and antifungal efficacy of polysaccharide-based nanoemulsions may be improved by ultrasonic treatment. This study paves the way for innovative, highly stable nanoemulsions.
    Matched MeSH terms: Nanoparticles/chemistry
  4. Colorimetric and fluorometric sensing of polar E120 in juice and environmental water samples using mannitol-functionalized magnetic nanoparticles and nitrogen-doped carbon dots
    Aburub SS, Rahim NY, Mahmoud AM, Maluin FN
    Spectrochim Acta A Mol Biomol Spectrosc, 2025 Feb 15;327:125380.
    PMID: 39522227 DOI: 10.1016/j.saa.2024.125380
    In this study, mannitol-functionalized magnetic nanoparticles (MMNPs) as a unique nanosorbent and N-doped fluorescent carbon dots (N-CDs) as a cost-effective nanosensor were created and utilized, for the first time, for dispersive micro-solid-phase extraction (Dµ-SPE) to determine carmine (E120) dye in water samples and juices. The modification of the magnetic nanoparticles with mannitol was designed to enhance the responsive potential for adsorption of the polar E120 dye from complex sample matrices through electrostatic interaction. The as-fabricated N-CDs fluorescent probe exhibited a high fluorescence quantum yield (Φs) of 43.1 %, allowing for accurate fluorometric detection of E120 dye. The as-synthesized MMNPs nanosorbent and fluorescent N-CDs nanoprobe were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA), and vibrating-sample magnetometer (VSM). Density functional theory (DFT) studied the E120 dye structure using Gaussian 09 to explore the interactions between E 120 dye molecules and MMNPs/N-CDs. The impact of the critical adsorption and detection experimental factors was investigated and adjusted. A minimal amount of MMNPs nanosorbent (150 mg) is sufficient for E120 extraction in an acceptable time of 15 min. Furthermore, with a high determination coefficient, the adsorption characteristics fit with the models of Langmuir isotherm and first-order kinetics. The maximum adsorption capacity (qm) of the as-fabricated MMNPs was 87.7 mg.g-1. After adsorption, E120 dye was fluorometrically analyzed using nitrogen-doped carbon dots as a fluorescent nanosensor via the inner filter effect (IFE) mechanism. Under the optimized conditions, the proposed fluorometric procedures showed a linear increase in the fluorescence ratio with increasing the E120 concentration in the range of 1.0 - 160.0 μg.mL-1 with detection (LOD) and quantitation (LOQ) limits of 0.27 and 0.83 μg.mL-1, respectively. The relative standard deviation (%RSD) did not exceed 2.34 %. The proposed methodology was successfully applied to determine E120 dye in juice and environmental water samples with % recovery ranged from 89.2-106.1 % and 92.9-107.2 %, respectively offering a reliable and environmentally friendly alternative to traditional detection methods with potential applications across various industries.
    Matched MeSH terms: Magnetite Nanoparticles/chemistry
  5. Antibacterial activity of zinc oxide nanoparticles against Shewanella putrefaciens and its application in preservation of large yellow croaker (Pseudosciaena crocea)
    Liu M, Mo Y, Dong Z, Yang H, Lin B, Li Y, et al.
    Food Res Int, 2025 Feb;201:115642.
    PMID: 39849782 DOI: 10.1016/j.foodres.2024.115642
    Specific spoilage organisms (SSOs) are the key factors affecting the deterioration of large yellow croaker. This study investigated the antibacterial activity and mechanism of Zinc oxide nanoparticles (ZnO-NPs) against Shewanella putrefaciens. The effects of different concentrations of ZnO-NPs (0.5, 1, 2 mg/mL) combined with seawater slurry ice preservation on storage quality and microbial community of large yellow croaker were further investigated. The results showed that ZnO-NPs had a strong antibacterial effect on Shewanella putrefaciens, which destroyed the integrity of the cell membrane, resulting in nucleic acid leakage and increased electrical conductivity. In addition, ZnO-NPs could effectively inhibit the proliferation of microorganisms, slow down the rate of lipid oxidation, delay the rise of pH value and total volatile basic nitrogen, and maintain the color of fish. Among them, 2 mg/mL ZnO-NPs treatment showed the best preservation effect on large yellow croaker. High-throughput sequencing results showed that Pseudoalteromonas and Shewanella became the dominant spoilage bacteria with the extension of storage time. ZnO-NPs significantly reduced the relative abundance of dominant spoilage bacteria and changed the microbial composition of fish. Inhibition of the growth of SSOs was important for delaying spoilage and prolonging the shelf-life of large yellow croaker. Therefore, ZnO-NPs combined with seawater slurry ice preservation could be used as a new storage method, which provides a new idea for food quality and safety control.
    Matched MeSH terms: Metal Nanoparticles/chemistry
  6. Triggering Mechanisms of Thermosensitive Nanoparticles Under Hyperthermia Condition
    Dabbagh A, Abdullah BJ, Abdullah H, Hamdi M, Kasim NH
    J Pharm Sci, 2015 Aug;104(8):2414-28.
    PMID: 26073304 DOI: 10.1002/jps.24536
    Nanoparticle-based hyperthermia is an effective therapeutic approach that allows time- and site-specific treatment with minimized off-site effects. The recent advances in materials science have led to design a diversity of thermosensitive nanostructures that exhibit different mechanisms of thermal response to the external stimuli. This article aims to provide an extensive review of the various triggering mechanisms in the nanostructures used as adjuvants to hyperthermia modalities. Understanding the differences between various mechanisms of thermal response in these nanostructures could help researchers in the selection of appropriate materials for each experimental and clinical condition as well as to address the current shortcomings of these mechanisms with improved material design.
    Matched MeSH terms: Nanoparticles/chemistry*; Metal Nanoparticles/chemistry
  7. Potential Biomedical Applications of Terbium-Based Nanoparticles (TbNPs): A Review on Recent Advancement
    Mohanto S, Biswas A, Gholap AD, Wahab S, Bhunia A, Nag S, et al.
    ACS Biomater Sci Eng, 2024 May 13;10(5):2703-2724.
    PMID: 38644798 DOI: 10.1021/acsbiomaterials.3c01969
    The scientific world is increasingly focusing on rare earth metal oxide nanomaterials due to their consequential biological prospects, navigated by breakthroughs in biomedical applications. Terbium belongs to rare earth elements (lanthanide series) and possesses remarkably strong luminescence at lower energy emission and signal transduction properties, ushering in wide applications for diagnostic measurements (i.e., bioimaging, biosensors, fluorescence imaging, etc.) in the biomedical sectors. In addition, the theranostic applications of terbium-based nanoparticles further permit the targeted delivery of drugs to the specific site of the disease. Furthermore, the antimicrobial properties of terbium nanoparticles induced via reactive oxygen species (ROS) cause oxidative damage to the cell membrane and nuclei of living organisms, ion release, and surface charge interaction, thus further creating or exhibiting excellent antioxidant characteristics. Moreover, the recent applications of terbium nanoparticles in tissue engineering, wound healing, anticancer activity, etc., due to angiogenesis, cell proliferation, promotion of growth factors, biocompatibility, cytotoxicity mitigation, and anti-inflammatory potentials, make this nanoparticle anticipate a future epoch of nanomaterials. Terbium nanoparticles stand as a game changer in the realm of biomedical research, proffering a wide array of possibilities, from revolutionary imaging techniques to advanced drug delivery systems. Their unique properties, including luminescence, magnetic characteristics, and biocompatibility, have redefined the boundaries of what can be achieved in biomedicine. This review primarily delves into various mechanisms involved in biomedical applications via terbium-based nanoparticles due to their physicochemical characteristics. This review article further explains the potential biomedical applications of terbium nanoparticles with in-depth significant mechanisms from the individual literature. This review additionally stands as the first instance to furnish a "single-platted" comprehensive acquaintance of terbium nanoparticles in shaping the future of healthcare as well as potential limitations and overcoming strategies that require exploration before being trialed in clinical settings.
    Matched MeSH terms: Nanoparticles/chemistry; Metal Nanoparticles/chemistry
  8. Fulltext Efficient chromium removal from leather industrial wastewater in batch experimental study: Green synthesis and characterization of zinc oxide nanoparticles using Ficus benghalensis extracts
    Irshad MA, Abdullah, Latif M, Nasim I, Nawaz R, Zahoor AF, et al.
    Ecotoxicol Environ Saf, 2024 Aug;281:116616.
    PMID: 38917589 DOI: 10.1016/j.ecoenv.2024.116616
    The urgent need to address the severe environmental risk posed by chromium-contaminated industrial wastewater necessitates the development of eco-friendly cleanup methodologies. Utilizing the Ficus benghalensis plant extracts, the present study aims to develop green zinc oxide nanoparticles for the removal of Cr metal ions from wastewater. The leaves of Ficus benghalensis, often known as the banyan tree, were used to extract a solution for synthesizing ZnO NPs. These nanoparticles were developed with the goal of efficiently eliminating chromium (Cr) from industrial effluents. Batch studies were carried out to assess the efficiency of these synthesized ZnO NPs in treating leather industrial effluent, with aiming for optimal chromium removal. This involved measuring the nanoparticles' capacity to adsorb Cr ions from wastewater samples by comparing chromium levels before and after treatment. Removal efficiency for Cr was estimated through the batches such as optimization of pH, contact time, initial Cr concentration and sorbent dose of ZnO NPs were of the batches. These synthesized ZnO NPs were found to be successful in lowering chromium levels in wastewater to meet permissible limit. The nanoparticles exhibited their highest absorption capacity, reaching 94 % (46 mg/g) at pH 4, with a contact time of 7 hours with the optimum sorbent dose of 0.6 g/L. Hence, the excellent adsorption capabilities of these nanoparticles, together with their environmentally benign manufacturing technique, provide a long-term and efficient solution for chromium-contaminated wastewater treatment. Its novel nature has the potential to significantly improve the safety and cleanliness of water ecosystems, protecting the both i.e. human health and the environment.
    Matched MeSH terms: Nanoparticles/chemistry; Metal Nanoparticles/chemistry
  9. Fulltext Molecular interaction of fibrinogen with zeolite nanoparticles
    Derakhshankhah H, Hosseini A, Taghavi F, Jafari S, Lotfabadi A, Ejtehadi MR, et al.
    Sci Rep, 2019 02 07;9(1):1558.
    PMID: 30733474 DOI: 10.1038/s41598-018-37621-4
    Fibrinogen is one of the key proteins that participate in the protein corona composition of many types of nanoparticles (NPs), and its conformational changes are crucial for activation of immune systems. Recently, we demonstrated that the fibrinogen highly contributed in the protein corona composition at the surface of zeolite nanoparticles. Therefore, understanding the interaction of fibrinogen with zeolite nanoparticles in more details could shed light of their safe applications in medicine. Thus, we probed the molecular interactions between fibrinogen and zeolite nanoparticles using both experimental and simulation approaches. The results indicated that fibrinogen has a strong and thermodynamically favorable interaction with zeolite nanoparticles in a non-cooperative manner. Additionally, fibrinogen experienced a substantial conformational change in the presence of zeolite nanoparticles through a concentration-dependent manner. Simulation results showed that both E- and D-domain of fibrinogen are bound to the EMT zeolite NPs via strong electrostatic interactions, and undergo structural changes leading to exposing normally buried sequences. D-domain has more contribution in this interaction and the C-terminus of γ chain (γ377-394), located in D-domain, showed the highest level of exposure compared to other sequences/residues.
    Matched MeSH terms: Nanoparticles/chemistry*; Metal Nanoparticles/chemistry
  10. Phyto-fabricated ZnO nanoparticles for anticancer, photo-antimicrobial effect on carbapenem-resistant/sensitive Pseudomonas aeruginosa and removal of tetracycline
    Venkatraman G, Mohan PS, Mashghan MM, Wong KC, Abdul-Rahman PS, Vellasamy KM, et al.
    Bioprocess Biosyst Eng, 2024 Aug;47(8):1163-1182.
    PMID: 38491194 DOI: 10.1007/s00449-024-02984-8
    Alternanthera sessilis (AS) leaf extract was used to synthesize zinc oxide nanoparticles (ZnO NPs). Bioanalytical characterization techniques such as X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) confirmed the formation of crystalline ZnO NPs with average sizes of 40 nm. The AS-ZnO NPs antimicrobial activity was analyzed under dark (D) and white light (WL) conditions. The improved antimicrobial activity was observed against Escherichia coli, Staphylococcus aureus and Bacillus subtilis at the minimal inhibitory concentration (MIC) of 125 and 62.5 µg/mL under WL than the D at 125 and 250 µg/mL for E. coli, B. subtilis, and Pseudomonas aeruginosa, respectively. In contrast, the growth of P. aeruginosa and S. aureus was not completely inhibited until 1 mg/mL AS-ZnO NPs under WL and D. Similarly, AS-ZnO NPs displayed a weaker inhibitory effect against carbapenem-sensitive P. aeruginosa (CSPA) and carbapenem-resistant P. aeruginosa (CRPA) strains of PAC023, PAC041 and PAC032, PAC045 under D. Interestingly, the distinct inhibitory effect was recorded against CSPA PAC041 and CRPA PAC032 in which the bacteria growth was inhibited 99.9% at 250, 500 µg/mL under WL. The cytotoxicity results suggested AS-ZnO NPs demonstrated higher toxicity to MCF-7 breast cancer cells than the RAW264.7 macrophage cells. Further, AS-ZnO NPs exhibited higher catalytic potential against tetracycline hydrochloride (TC-H) degradation at 65.6% and 60.8% under WL than the dark at 59.35% and 48.6% within 120 min. Therefore, AS-ZnO NPs can be used to design a photo-improved antimicrobial formulation and environmental catalyst for removing TC-H from wastewater.
    Matched MeSH terms: Nanoparticles/chemistry; Metal Nanoparticles/chemistry
  11. Freeze-drying synthesis of mesoporous magnetic grafted chitosan/calcium oxide nanoparticle for remazol brilliant blue dye removal: A statistical optimization
    Jawad AH, Maharani RA, Hapiz A, Khadiran T, Jani NA, ALOthman ZA, et al.
    Int J Biol Macromol, 2025 Jan;286:138373.
    PMID: 39643197 DOI: 10.1016/j.ijbiomac.2024.138373
    Herein, a mesoporous magnetic chitosan-salicylaldehyde/calcium oxide nanoparticle (CS-SL/CaO/Fe3O4) biocomposite adsorbent that was prepared via freeze-drying. The CS-SL/CaO/Fe3O4 was utilized for the adsorption of ramazol brilliant blue (RBB) dye from aqueous solution. The physicochemical properties of the CS-SL/CaO/Fe3O4 were evaluated using diverse characterization techniques, including BET, XRD, FTIR, FESEM-EDX, CHNS, and pHpzc. The three main factors for adsorption included the following A: CS-SL/CaO/Fe3O4 dosage (0.02-0.1 g/100 mL), B: pH (4-10), and C: Time (60-540 min). These factors were improved using statistical methods, specifically the Box-Behnken design (BBD). The optimal conditions for achieving maximum RBB removal (62.5 %) are listed: CS-SL/CaO/Fe3O4 dosage of 0.1 g/100 mL, a solution pH of 7, and a contact time of 540 min. The adsorption kinetics and equilibrium isotherms were well described by the pseudo first order (PFO) kinetic and Langmuir isotherm models, respectively. Thus, the CS-SL/CaO/Fe3O4 material has a maximum adsorption capacity (qmax) of 63.3 mg/g for RBB at 25 °C. The adsorption mechanism of RBB onto the CS-SL/CaO/Fe3O4 surface was attributed to electrostatic forces, n-π stacking, H-bonding, and Pi-Pi interactions. Thus, CS-SL/CaO/Fe3O4 represents a recoverable magnetic adsorbent with potential for capture of organic dyes from wastewater.
    Matched MeSH terms: Nanoparticles/chemistry; Magnetite Nanoparticles/chemistry
  12. Anti-diabetic and anti-microbial activity of aspalathus linearis and syzygium aromaticum formulation mediated zinc oxide nanoparticles
    Geetha RV, Shwetha K, Annika R, Rajeshkumar S, Pradeep M, Jayasree A
    Med J Malaysia, 2025 Jan;80(Suppl 1):10-16.
    PMID: 39773936
    INTRODUCTION: Zinc oxide nanoparticles (ZnO NPs) exhibit a wide range of biomedical applications majorly used as antiinflammatory, anti-cancer, anti-diabetic, and anti-microbial activity and other biomedical applications because they show less toxicity and are very compatible. Zinc metal is an inorganic and essential element in the human body at the trace level. ZnO NPs are also GRAS substances (Generally Recognized As Safe). This study's main objective is synthesizing zinc oxide nanoparticles using red tea & clove mediated herbal formulation and screening for its antimicrobial, and anti-diabetic properties.

    MATERIALS AND METHODS: Red tea and clove-mediated ZnO NPs were synthesized using the green synthesis method. The anti-microbial activity was tested against oral pathogens using the agar well diffusion method, while the anti-diabetic activity was estimated using the alpha-amylase inhibitory assay method by using red tea and clovemediated ZnO NPs.

    RESULTS: ZnO NPs were successfully synthesized using red tea and clove-formulated extract. The synthesized ZnO NPs using Aspalathus linearis (red tea) and Syzygium aromaticum (clove) mediated ZnO NPs were characterized using UV visible spectrophotometry and SEM (Scanning Electron Microscope) analysis. The green synthesized ZnO NPs show promising anti-microbial activity by exhibiting a 12 mm zone of inhibition against S. aureus, 11 mm in E. faecalis, 9 mm in S. mutans, and 11 mm in C. albicans. In anti-diabetic activity, the green synthesized ZnO NPs showed a maximum inhibition percentage of up to 80% at the maximum concentration of 50 µg/mL.

    CONCLUSION: Green synthesized ZnO NPs using red tea and clove showed maximum efficacy in anti-microbial properties which can lead to huge potential use as antibacterial agents. Simultaneously, anti-diabetic activity showed an excellent inhibition percentage which can be a potent therapeutic agent in the field of nanomedicine in diabetes management.

    Matched MeSH terms: Nanoparticles/chemistry; Metal Nanoparticles/chemistry
  13. Synthesis of flexirubin-mediated silver nanoparticles using Chryseobacterium artocarpi CECT 8497 and investigation of its anticancer activity
    Venil CK, Sathishkumar P, Malathi M, Usha R, Jayakumar R, Yusoff ARM, et al.
    Mater Sci Eng C Mater Biol Appl, 2016 Feb;59:228-234.
    PMID: 26652368 DOI: 10.1016/j.msec.2015.10.019
    In this work, the synthesis of silver nanoparticles from a pigment produced by a recently-discovered bacterium, Chryseobacterium artocarpi CECT 8497, was achieved, followed by an investigation of its anticancer properties. The bacterial pigment was identified as flexirubin following NMR ((1)H NMR and (13)C NMR), UV-Vis, and LC-MS analysis. An aqueous silver nitrate solution was treated with isolated flexirubin to produce silver nanoparticles. The synthesised silver nanoparticles were subsequently characterised by UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD), and Fourier Transform Infrared (FTIR) Spectroscopy methodologies. Furthermore, the anticancer effects of synthesised silver nanoparticles in a human breast cancer cell line (MCF-7) were evaluated. The tests showed significant cytotoxicity activity of the silver nanoparticles in the cultured cells, with an IC50 value of 36μgmL(-1). This study demonstrates that silver nanoparticles, synthesised from flexirubin from C. artocarpi CECT 8497, may have potential as a novel chemotherapeutic agent.
    Matched MeSH terms: Metal Nanoparticles/chemistry*
  14. Fulltext Thickness Dependent Nanostructural, Morphological, Optical and Impedometric Analyses of Zinc Oxide-Gold Hybrids: Nanoparticle to Thin Film
    Perumal V, Hashim U, Gopinath SC, Haarindraprasad R, Liu WW, Poopalan P, et al.
    PLoS One, 2015;10(12):e0144964.
    PMID: 26694656 DOI: 10.1371/journal.pone.0144964
    The creation of an appropriate thin film is important for the development of novel sensing surfaces, which will ultimately enhance the properties and output of high-performance sensors. In this study, we have fabricated and characterized zinc oxide (ZnO) thin films on silicon substrates, which were hybridized with gold nanoparticles (AuNPs) to obtain ZnO-Aux (x = 10, 20, 30, 40 and 50 nm) hybrid structures with different thicknesses. Nanoscale imaging by field emission scanning electron microscopy revealed increasing film uniformity and coverage with the Au deposition thickness. Transmission electron microscopy analysis indicated that the AuNPs exhibit an increasing average diameter (5-10 nm). The face center cubic Au were found to co-exist with wurtzite ZnO nanostructure. Atomic force microscopy observations revealed that as the Au content increased, the overall crystallite size increased, which was supported by X-ray diffraction measurements. The structural characterizations indicated that the Au on the ZnO crystal lattice exists without any impurities in a preferred orientation (002). When the ZnO thickness increased from 10 to 40 nm, transmittance and an optical bandgap value decreased. Interestingly, with 50 nm thickness, the band gap value was increased, which might be due to the Burstein-Moss effect. Photoluminescence studies revealed that the overall structural defect (green emission) improved significantly as the Au deposition increased. The impedance measurements shows a decreasing value of impedance arc with increasing Au thicknesses (0 to 40 nm). In contrast, the 50 nm AuNP impedance arc shows an increased value compared to lower sputtering thicknesses, which indicated the presence of larger sized AuNPs that form a continuous film, and its ohmic characteristics changed to rectifying characteristics. This improved hybrid thin film (ZnO/Au) is suitable for a wide range of sensing applications.
    Matched MeSH terms: Metal Nanoparticles/chemistry*
  15. Fulltext Synthesis of silver nanoparticles dispersed in various aqueous media using laser ablation
    Tajdidzadeh M, Azmi BZ, Yunus WM, Talib ZA, Sadrolhosseini AR, Karimzadeh K, et al.
    ScientificWorldJournal, 2014;2014:324921.
    PMID: 25295298 DOI: 10.1155/2014/324921
    The particle size, morphology, and stability of Ag-NPs were investigated in the present study. A Q-Switched Nd: YAG pulsed laser (λ = 532 nm, 360 mJ/pulse) was used for ablation of a pure Ag plate for 30 min to prepare Ag-NPs in the organic compound such as ethylene glycol (EG) and biopolymer such as chitosan. The media (EG, chitosan) permitted the making of NPs with well dispersed and average size of Ag-NPs in EG is about 22 nm and in chitosan is about 10 nm in spherical form. Particle size, morphology, and stability of NPs were compared with distilled water as a reference. The stability of the samples was studied by measuring UV-visible absorption spectra of samples after one month. The result indicated that the formation efficiency of NPs in chitosan was higher than other media and NPs in chitosan solution were more stable than other media during one month storage. This method for synthesis of silver NPs could be as a green method due to its environmentally friendly nature.
    Matched MeSH terms: Metal Nanoparticles/chemistry*
  16. Fulltext Synthesis and ultraviolet visible spectroscopy studies of chitosan capped gold nanoparticles and their reactions with analytes
    Mohd Sultan N, Johan MR
    ScientificWorldJournal, 2014;2014:184604.
    PMID: 25215315 DOI: 10.1155/2014/184604
    Gold nanoparticles (AuNPs) had been synthesized with various molarities and weights of reducing agent, monosodium glutamate (MSG), and stabilizer chitosan, respectively. The significance of chitosan as stabilizer was distinguished through transmission electron microscopy (TEM) images and UV-Vis absorption spectra in which the interparticles distance increases whilst retaining the surface plasmon resonance (SPR) characteristics peak. The most stable AuNPs occurred for composition with the lowest (1 g) weight of chitosan. AuNPs capped with chitosan size stayed small after 1 month aging compared to bare AuNPs. The ability of chitosan capped AuNPs to uptake analyte was studied by employing amorphous carbon nanotubes (α-CNT), copper oxide (Cu2O), and zinc sulphate (ZnSO4) as the target material. The absorption spectra showed dramatic intensity increased and red shifted once the analyte was added to the chitosan capped AuNPs.
    Matched MeSH terms: Nanoparticles/chemistry*
  17. Fulltext Effect of zirconium oxide nanofiller and dibutyl phthalate plasticizer on ionic conductivity and optical properties of solid polymer electrolyte
    Yasin SM, Ibrahim S, Johan MR
    ScientificWorldJournal, 2014;2014:547076.
    PMID: 25133244 DOI: 10.1155/2014/547076
    New solid polymer electrolytes (SPE) based on poly(ethylene oxide) (PEO) doped with lithium trifluoromethanesulfonate (LiCF3SO3), dibutyl phthalate (DBP) plasticizer, and zirconium oxide (ZrO2) nanoparticles were prepared by solution-casting technique. The conductivity was enhanced by addition of dibutyl phthalate (DBP) plasticizer and ZrO2 nanofiller with maximum conductivity (1.38 × 10(-4) Scm(-1)). The absorption edge and band gap values showed decreases upon addition of LiSO3CF3, DBP, and ZrO2 due to the formation of localized states in the SPE and the degree of disorder in the films increased.
    Matched MeSH terms: Nanoparticles/chemistry*
  18. Effect of copper oxide nanoparticles on the conformation and activity of β-galactosidase
    Rabbani G, Khan MJ, Ahmad A, Maskat MY, Khan RH
    Colloids Surf B Biointerfaces, 2014 Nov 1;123:96-105.
    PMID: 25260221 DOI: 10.1016/j.colsurfb.2014.08.035
    The primary objective of this study is to explore the interaction of β-galactosidase with copper oxide nanoparticles (CuO NPs). Steady-state absorption, fluorescence and circular dichroism (CD) spectroscopic techniques have been employed to unveil the conformational changes of β-galactosidase induced by the binding of CuO NPs. Temperature dependent fluorescence quenching results indicates a static quenching mechanism in the present case. The binding thermodynamic parameters delineate the predominant role of H-bonding and van der Waals forces between β-galactosidase and CuO NPs binding process. The binding was studied by isothermal titration calorimetry (ITC) and the result revealed that the complexation is enthalpy driven, the ΔH°<0, ΔS°<0 indicates the formation of hydrogen bonds between β-galactosidase and CuO NPs occurs. Disruption of the native conformation of the protein upon binding with CuO NPs is reflected through a reduced functionality (in terms of hydrolase activity) of the protein CuO NPs conjugate system in comparison to the native protein and CuO NPs exhibited a competitive mode of inhibition. This also supports the general belief that H-bond formation occurs with NPs is associated with a lesser extent of modification in the native structure. Morphological features and size distributions were investigated using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Additionally the considerable increase in the Rh following the addition of CuO NPs accounts for the unfolding of β-galactosidase. Chemical and thermal unfolding of β-galactosidase, when carried out in the presence of CuO NPs, also indicated a small perturbation in the protein structure. These alterations in functional activity of nanoparticle bound β-galactosidase which will have important consequences should be taken into consideration while using nanoparticles for diagnostic and therapeutic purposes.
    Matched MeSH terms: Metal Nanoparticles/chemistry*
  19. Functionalized fullerene (C₆₀) as a potential nanomediator in the fabrication of highly sensitive biosensors
    Afreen S, Muthoosamy K, Manickam S, Hashim U
    Biosens Bioelectron, 2015 Jan 15;63:354-364.
    PMID: 25125029 DOI: 10.1016/j.bios.2014.07.044
    Designing a biosensor for versatile biomedical applications is a sophisticated task and how dedicatedly functionalized fullerene (C60) can perform on this stage is a challenge for today and tomorrow's nanoscience and nanotechnology. Since the invention of biosensor, many ideas and methods have been invested to upgrade the functionality of biosensors. Due to special physicochemical characteristics, the novel carbon material "fullerene" adds a new dimension to the construction of highly sensitive biosensors. The prominent aspects of fullerene explain its outstanding performance in biosensing devices as a mediator, e.g. fullerene in organic solvents exhibits five stages of reversible oxidation/reduction, and hence fullerene can work either as an electrophile or nucleophile. Fullerene is stable and its spherical structure produces an angle strain which allows it to undergo characteristic reactions of addition to double bonds (hybridization which turns from sp(2) to sp(3)). Research activities are being conducted worldwide to invent a variety of methods of fullerene functionalization with a purpose of incorporating it effectively in biosensor devices. The different types of functionalization methods include modification of fullerene into water soluble derivatives and conjugation with enzymes and/or other biomolecules, e.g. urease, glucose oxidase, hemoglobin, myoglobin (Mb), conjugation with metals e.g. gold (Au), chitosan (CS), ferrocene (Fc), etc. to enhance the sensitivity of biosensors. The state-of-the-art research on fullerene functionalization and its application in sensor devices has proven that fullerene can be implemented successfully in preparing biosensors to detect glucose level in blood serum, urea level in urine solution, hemoglobin, immunoglobulin, glutathione in real sample for pathological purpose, to identify doping abuse, to analyze pharmaceutical preparation and even to detect cancer and tumor cells at an earlier stage. Employing fullerene-metal matrix for the detection of tumor and cancer cells is also possible by the inclusion of fullerene in single-walled carbon nanotubes (SWCNTs) known as peapods as well as in double-walled carbon nanotubes (DWCNTs), to augment the effectiveness of biosensors. This review discusses various approaches that have been reported for functionalizing fullerene (C60) derivatives and their application in different types of biosensor fabrication.
    Matched MeSH terms: Metal Nanoparticles/chemistry
  20. Fulltext Synthesis and optical enhancement of amorphous carbon nanotubes/silver nanohybrids via chemical route at low temperature
    Han TK, Fen LB, Nee NM, Johan MR
    ScientificWorldJournal, 2014;2014:847806.
    PMID: 24995365 DOI: 10.1155/2014/847806
    We report the synthesis of amorphous carbon nanotubes/silver (αCNTs/Ag) nanohybrids via simple chemical route without additional reactant and surfactant at low temperature. Field emission scanning microscope (FESEM) and transmission electron microscope (TEM) confirmed formation of CNTs. X-ray diffraction (XRD) pattern confirmed the amorphous phase of carbon and the formation of Ag nanoparticles crystalline phase. Raman spectra revealed the amorphous nature of α CNTs. UV-visible spectroscopy showed enhancement of optical properties of α CNTs/Ag nanohybrids.
    Matched MeSH terms: Metal Nanoparticles/chemistry*
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