Displaying publications 1 - 20 of 79 in total

Abstract:
Sort:
  1. 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: Nanotechnology/methods*
  2. Synthesis and characterization of polymeric V2O5/AlO(OH) with nanopores on alumina support
    Ahmad AL, Abd Shukor SR, Leo CP
    J Nanosci Nanotechnol, 2006 Dec;6(12):3910-4.
    PMID: 17256351
    Polymeric vanadium pentoxide gel was formed via the reaction of V2O5 powder with hydrogen peroxide. The polymeric vanadium pentoxide gel was then dispersed in alumina gel. Different vanadium loading composites were coated on alumina support and calcined at 500 degrees C for 1 hr. These composite layers were characterized using TGA, FT-IR, XRD, SEM, and Autosorb. It was found that the lamellar structure of polymerized vanadium pentoxide was retained in the inorganic matrix. Crystalline alumina in gamma phase was formed after calcinations. However, the vanadium-alumina mixed oxides are lack of the well defined PXRD peaks for polycrystalline V2O5. This is possibly because the vanadia species are highly dispersed in the alumina matrix or the vanadia species are dispersed as crystalline which is smaller than 4 nm. In addition, the imbedded polymeric vanadium oxide improved the specific area and average pore diameter of the composite layer.
    Matched MeSH terms: Nanotechnology/methods*
  3. Fulltext Comparison of in situ polymerization and solution-dispersion techniques in the preparation of Polyimide/Montmorillonite (MMT) Nanocomposites
    Ahmad MB, Gharayebi Y, Salit MS, Hussein MZ, Shameli K
    Int J Mol Sci, 2011;12(9):6040-50.
    PMID: 22016643 DOI: 10.3390/ijms12096040
    In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3',4,4'-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT) for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique.
    Matched MeSH terms: Nanotechnology/methods*
  4. Fulltext Analytical calculation of sensing parameters on carbon nanotube based gas sensors
    Akbari E, Buntat Z, Ahmad MH, Enzevaee A, Yousof R, Iqbal SM, et al.
    Sensors (Basel), 2014;14(3):5502-15.
    PMID: 24658617 DOI: 10.3390/s140305502
    Carbon Nanotubes (CNTs) are generally nano-scale tubes comprising a network of carbon atoms in a cylindrical setting that compared with silicon counterparts present outstanding characteristics such as high mechanical strength, high sensing capability and large surface-to-volume ratio. These characteristics, in addition to the fact that CNTs experience changes in their electrical conductance when exposed to different gases, make them appropriate candidates for use in sensing/measuring applications such as gas detection devices. In this research, a model for a Field Effect Transistor (FET)-based structure has been developed as a platform for a gas detection sensor in which the CNT conductance change resulting from the chemical reaction between NH3 and CNT has been employed to model the sensing mechanism with proposed sensing parameters. The research implements the same FET-based structure as in the work of Peng et al. on nanotube-based NH3 gas detection. With respect to this conductance change, the I-V characteristic of the CNT is investigated. Finally, a comparative study shows satisfactory agreement between the proposed model and the experimental data from the mentioned research.
    Matched MeSH terms: Nanotechnology/methods*
  5. Formulation and stability of whitening VCO-in-water nano-cream
    Al-Edresi S, Baie S
    Int J Pharm, 2009 May 21;373(1-2):174-8.
    PMID: 19429303 DOI: 10.1016/j.ijpharm.2009.02.011
    Virgin coconut oil (VCO)-in-water, nano-emulsion in the form of cream stabilized by Emulium Kappa as an emulsifier, was prepared by using the Emulsion Inversion Point method. A nano-emulsion with droplet size <300 nm was then obtained. VCO has recently become a more popular new material in the cosmetic industries. Emulium Kappa is an ionic emulsifier that contains sodium stearoyl lactylate, the active whitening ingredient was Kojic Dipalmitate. Ostwald ripening is the main destabilizing factor for the nano-emulsion. This decline can be reduced by adding non-soluble oil, namely squalene, to the virgin coconut oil. We tested VCO:squalene in the ratios of 10:0, 9.8:0.2, 9.6:0.4, 9.4:0.6, 9.2:0.8, 9:1 and 8:2 and discovered that squalene's higher molecular weight (above critical molecular weight) resulted in low polarity and insolubility in the continuous phase. The continuous partitioning between the droplets results in the decline of Ostwald ripening. Furthermore, flocculation may occur due to the instability of nano-emulsion, especially for the preparations with little or no squalene at all. The stability of the nano-emulsion was evaluated by the electrophoretic properties of the emulsion droplets. The zeta potential values for the emulsion increased as the percentage of squalene oil increased.
    Matched MeSH terms: Nanotechnology/methods*
  6. Fulltext Engineered Nanomaterials: The Challenges and Opportunities for Nanomedicines
    Albalawi F, Hussein MZ, Fakurazi S, Masarudin MJ
    Int J Nanomedicine, 2021;16:161-184.
    PMID: 33447033 DOI: 10.2147/IJN.S288236
    The emergence of nanotechnology as a key enabling technology over the past years has opened avenues for new and innovative applications in nanomedicine. From the business aspect, the nanomedicine market was estimated to worth USD 293.1 billion by 2022 with a perception of market growth to USD 350.8 billion in 2025. Despite these opportunities, the underlying challenges for the future of engineered nanomaterials (ENMs) in nanomedicine research became a significant obstacle in bringing ENMs into clinical stages. These challenges include the capability to design bias-free methods in evaluating ENMs' toxicity due to the lack of suitable detection and inconsistent characterization techniques. Therefore, in this literature review, the state-of-the-art of engineered nanomaterials in nanomedicine, their toxicology issues, the working framework in developing a toxicology benchmark and technical characterization techniques in determining the toxicity of ENMs from the reported literature are explored.
    Matched MeSH terms: Nanotechnology/methods*
  7. Lung cancer: active therapeutic targeting and inhalational nanoproduct design
    Alhajj N, Chee CF, Wong TW, Rahman NA, Abu Kasim NH, Colombo P
    Expert Opin Drug Deliv, 2018 12;15(12):1223-1247.
    PMID: 30422017 DOI: 10.1080/17425247.2018.1547280
    INTRODUCTION: Pulmonary drug delivery is organ-specific and benefits local drug action for lung cancer. The use of nanotechnology and targeting ligand enables cellular-specific drug action. Combination approaches increase therapeutic efficacy and reduce adverse effects of cancer chemotherapeutics that have narrow therapeutic index window and high cytotoxicity levels. The current progress of inhaled cancer chemotherapeutics has not been examined with respect to targeting strategy and clinical application potential.

    AREAS COVERED: This review examines the state of the art in passive (processing and formulation) and active (targeting ligand and receptor binding) technologies in association with the use of nanocarrier to combat lung cancer. It highlights routes to equip nanocarrier with targeting ligands as a function of the chemistry of participating biomolecules and challenges in inhalational nanoproduct development and clinical applications. Both research and review articles were examined using the Scopus, Elsevier, Web of Science, Chemical Abstracts, Medline, CASREACT, CHEMCATS, and CHEMLIST database with the majority of information retrieved between those of 2000-2018.

    EXPERT COMMENTARY: The therapeutic efficacy of targeting ligand-decorated nanocarriers needs to be demonstrated in vivo in the form of finished inhalational products. Their inhalation efficiency and medical responses require further examination. Clinical application of inhaled nanocancer chemotherapeutics is premature.

    Matched MeSH terms: Nanotechnology/methods*
  8. Nanoparticle sensor for label free detection of swine DNA in mixed biological samples
    Ali ME, Hashim U, Mustafa S, Man YB, Yusop MH, Bari MF, et al.
    Nanotechnology, 2011 May 13;22(19):195503.
    PMID: 21430321 DOI: 10.1088/0957-4484/22/19/195503
    We used 40 ± 5 nm gold nanoparticles (GNPs) as colorimetric sensor to visually detect swine-specific conserved sequence and nucleotide mismatch in PCR-amplified and non-amplified mitochondrial DNA mixtures to authenticate species. Colloidal GNPs changed color from pinkish-red to gray-purple in 2 mM PBS. Visually observed results were clearly reflected by the dramatic reduction of surface plasmon resonance peak at 530 nm and the appearance of new features in the 620-800 nm regions in their absorption spectra. The particles were stabilized against salt-induced aggregation upon the adsorption of single-stranded DNA. The PCR products, without any additional processing, were hybridized with a 17-base probe prior to exposure to GNPs. At a critical annealing temperature (55 °C) that differentiated matched and mismatched base pairing, the probe was hybridized to pig PCR product and dehybridized from the deer product. The dehybridized probe stuck to GNPs to prevent them from salt-induced aggregation and retained their characteristic red color. Hybridization of a 27-nucleotide probe to swine mitochondrial DNA identified them in pork-venison, pork-shad and venison-shad binary admixtures, eliminating the need of PCR amplification. Thus the assay was applied to authenticate species both in PCR-amplified and non-amplified heterogeneous biological samples. The results were determined visually and validated by absorption spectroscopy. The entire assay (hybridization plus visual detection) was performed in less than 10 min. The LOD (for genomic DNA) of the assay was 6 µg ml(-1) swine DNA in mixed meat samples. We believe the assay can be applied for species assignment in food analysis, mismatch detection in genetic screening and homology studies between closely related species.
    Matched MeSH terms: Nanotechnology/methods*
  9. Fulltext Effects of homogenization process parameters on physicochemical properties of astaxanthin nanodispersions prepared using a solvent-diffusion technique
    Anarjan N, Jafarizadeh-Malmiri H, Nehdi IA, Sbihi HM, Al-Resayes SI, Tan CP
    Int J Nanomedicine, 2015;10:1109-18.
    PMID: 25709435 DOI: 10.2147/IJN.S72835
    Nanodispersion systems allow incorporation of lipophilic bioactives, such as astaxanthin (a fat soluble carotenoid) into aqueous systems, which can improve their solubility, bioavailability, and stability, and widen their uses in water-based pharmaceutical and food products. In this study, response surface methodology was used to investigate the influences of homogenization time (0.5-20 minutes) and speed (1,000-9,000 rpm) in the formation of astaxanthin nanodispersions via the solvent-diffusion process. The product was characterized for particle size and astaxanthin concentration using laser diffraction particle size analysis and high performance liquid chromatography, respectively. Relatively high determination coefficients (ranging from 0.896 to 0.969) were obtained for all suggested polynomial regression models. The overall optimal homogenization conditions were determined by multiple response optimization analysis to be 6,000 rpm for 7 minutes. In vitro cellular uptake of astaxanthin from the suggested individual and multiple optimized astaxanthin nanodispersions was also evaluated. The cellular uptake of astaxanthin was found to be considerably increased (by more than five times) as it became incorporated into optimum nanodispersion systems. The lack of a significant difference between predicted and experimental values confirms the suitability of the regression equations connecting the response variables studied to the independent parameters.
    Matched MeSH terms: Nanotechnology/methods*
  10. Molecular filter on-chip design for drug targeting use
    Aziz MS, Jukgoljan B, Daud S, Tan TS, Ali J, Yupapin PP
    Artif Cells Nanomed Biotechnol, 2013 Jun;41(3):178-83.
    PMID: 22991944 DOI: 10.3109/10731199.2012.715087
    This paper presents the use of a modified add/drop optical filter incorporating with microring resonators known as a PANDA microring resonator system which can fabricate on small chip. By using an optical tweezer, the required molecules can be trapped and moved to the required destinations at the add/drop ports. The novelty is that the stored molecules in the designed chip can transport via the optical waveguide and can also be used to form molecular filter, which is an important technique for drug delivery, drug targeting, and molecular electronics. Results have shown that the multivariable filter can be obtained by tunable trapping control.
    Matched MeSH terms: Nanotechnology/methods
  11. Fulltext Modeling and analysis of a microresonating biosensor for detection of Salmonella bacteria in human blood
    Bahadoran M, Noorden AF, Chaudhary K, Mohajer FS, Aziz MS, Hashim S, et al.
    Sensors (Basel), 2014;14(7):12885-99.
    PMID: 25046015 DOI: 10.3390/s140712885
    A new photonics biosensor configuration comprising a Double-side Ring Add-drop Filter microring resonator (DR-ADF) made from SiO2-TiO2 material is proposed for the detection of Salmonella bacteria (SB) in blood. The scattering matrix method using inductive calculation is used to determine the output signal's intensities in the blood with and without presence of Salmonella. The change in refractive index due to the reaction of Salmonella bacteria with its applied antibody on the flagellin layer loaded on the sensing and detecting microresonator causes the increase in through and dropper port's intensities of the output signal which leads to the detection of SB in blood. A shift in the output signal wavelength is observed with resolution of 0.01 nm. The change in intensity and shift in wavelength is analyzed with respect to the change in the refractive index which contributes toward achieving an ultra-high sensitivity of 95,500 nm/RIU which is almost two orders higher than that of reported from single ring sensors and the limit of detection is in the order of 1 × 10(-8) RIU. In applications, such a system can be employed for a high sensitive and fast detection of bacteria.
    Matched MeSH terms: Nanotechnology/methods
  12. Fulltext Nanoparticles Biosynthesized by Fungi and Yeast: A Review of Their Preparation, Properties, and Medical Applications
    Boroumand Moghaddam A, Namvar F, Moniri M, Md Tahir P, Azizi S, Mohamad R
    Molecules, 2015;20(9):16540-65.
    PMID: 26378513 DOI: 10.3390/molecules200916540
    In the field of nanotechnology, the use of various biological units instead of toxic chemicals for the reduction and stabilization of nanoparticles, has received extensive attention. Among the many possible bio resources, biologically active products from fungi and yeast represent excellent scaffolds for this purpose. Since fungi and yeast are very effective secretors of extracellular enzymes and number of species grow fast and therefore culturing and keeping them in the laboratory are very simple. They are able to produce metal nanoparticles and nanostructure via reducing enzyme intracellularly or extracellularly. The focus of this review is the application of fungi and yeast in the green synthesis of inorganic nanoparticles. Meanwhile the domain of biosynthesized nanoparticles is somewhat novel; the innovative uses in nano medicine in different areas including the delivery of drug, cancer therapy, antibacterial, biosensors, and MRI and medical imaging are reviewed. The proposed signaling pathways of nanoparticles induced apoptosis in cancerous cells and anti-angiogenesis effects also are reviewed. In this article, we provide a short summary of the present study universally on the utilization of eukaryotes like yeast and fungi in the biosynthesis of nanoparticles (NPs) and their uses.
    Matched MeSH terms: Nanotechnology/methods*
  13. Fulltext Facile hydrothermal preparation of titanium dioxide decorated reduced graphene oxide nanocomposite
    Chang BY, Huang NM, An'amt MN, Marlinda AR, Norazriena Y, Muhamad MR, et al.
    Int J Nanomedicine, 2012;7:3379-87.
    PMID: 22848166 DOI: 10.2147/IJN.S28189
    A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte.
    Matched MeSH terms: Nanotechnology/methods*
  14. Rising horizon in circumventing multidrug resistance in chemotherapy with nanotechnology
    Choudhury H, Pandey M, Yin TH, Kaur T, Jia GW, Tan SQL, et al.
    Mater Sci Eng C Mater Biol Appl, 2019 Aug;101:596-613.
    PMID: 31029353 DOI: 10.1016/j.msec.2019.04.005
    Multidrug resistance (MDR) is one of the key barriers in chemotherapy, leading to the generation of insensitive cancer cells towards administered therapy. Genetic and epigenetic alterations of the cells are the consequences of MDR, resulted in drug resistivity, which reflects in impaired delivery of cytotoxic agents to the cancer site. Nanotechnology-based nanocarriers have shown immense shreds of evidence in overcoming these problems, where these promising tools handle desired dosage load of hydrophobic chemotherapeutics to facilitate designing of safe, controlled and effective delivery to specifically at tumor microenvironment. Therefore, encapsulating drugs within the nano-architecture have shown to enhance solubility, bioavailability, drug targeting, where co-administered P-gp inhibitors have additionally combat against developed MDR. Moreover, recent advancement in the stimuli-sensitive delivery of nanocarriers facilitates a tumor-targeted release of the chemotherapeutics to reduce the associated toxicities of chemotherapeutic agents in normal cells. The present article is focused on MDR development strategies in the cancer cell and different nanocarrier-based approaches in circumventing this hurdle to establish an effective therapy against deadliest cancer disease.
    Matched MeSH terms: Nanotechnology/methods*
  15. Current and future envision on developing biosensors aided by 2D molybdenum disulfide (MoS2) productions
    Dalila R N, Md Arshad MK, Gopinath SCB, Norhaimi WMW, Fathil MFM
    Biosens Bioelectron, 2019 May 01;132:248-264.
    PMID: 30878725 DOI: 10.1016/j.bios.2019.03.005
    Two-dimensional (2D) layered nanomaterials have triggered an intensive interest due to the fascinating physiochemical properties with the exceptional physical, optical and electrical characteristics that transpired from the quantum size effect of their ultra-thin structure. Among the family of 2D nanomaterials, molybdenum disulfide (MoS2) features distinct characteristics related to the existence of direct energy bandgap, which significantly lowers the leakage current and surpasses other 2D materials. In this overview, we expatiate the novel strategies to synthesize MoS2 that cover techniques such as liquid exfoliation, chemical vapour deposition, mechanical exfoliation, hydrothermal reaction, and Van Der Waal epitaxial growth on the substrate. We extend the discussion on the recent progress in biosensing applications of the produced MoS2, highlighting the important surface-to-volume of ultrathin MoS2 structure, which enhances the overall performance of the devices. Further, envisioned the missing piece with the current MoS2-based biosensors towards developing the future strategies.
    Matched MeSH terms: Nanotechnology/methods*
  16. Green Nanotechnology for Synthesis and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) nanoparticles for sustained bortezomib release using supercritical CO2 assisted particle formation combined with electrodeposition
    Demirdöğen RE, Emen FM, Ocakoglu K, Murugan P, Sudesh K, Avşar G
    Int J Biol Macromol, 2018 Feb;107(Pt A):436-445.
    PMID: 28888547 DOI: 10.1016/j.ijbiomac.2017.09.011
    Carbon dioxide assisted particle formation combined with electrospraying using supercritical CO2 (scCO2) as an aid (Carbon Dioxide Assisted Nebulization-Electrodeposition, CAN-ED) was used to produce Bortezomib loaded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) P(3HB-co-3HHx) nanoparticles for sustained release. The morphology and structure of the prepared nanoparticles were investigated by SEM, TEM and FT-IR spectroscopy. Average diameter of particles obtained was 155nm and the average core sizes of P(3HB-co-3HHx) nanoparticles were between 6 and 13nm. The drug loading capacity, drug release and stability of Bortezomib loaded P(3HB-co-3HHx) nanoparticles were analyzed. The maximum loading capacity was achieved at pH=6.0 in phosphate buffer (K2HPO4/KH2PO4). It was found that temperature did not affect the stability of Bortezomib loaded nanoparticles and it was good both at 37°C and 4°C. This study pointed out that CAN-ED is a green method to produce P(3HB-co-3HHx) nanoparticles for pH responsive targeting of Bortezomib especially to parts of the body where size exclusion is not crucial.
    Matched MeSH terms: Nanotechnology/methods
  17. Targeting microRNAs using nanotechnology in pulmonary diseases
    Dua K, Chellappan DK, Singhvi G, de Jesus Andreoli Pinto T, Gupta G, Hansbro PM
    Panminerva Med, 2018 Dec;60(4):230-231.
    PMID: 30563304 DOI: 10.23736/S0031-0808.18.03459-6
    Matched MeSH terms: Nanotechnology/methods*
  18. Fulltext Microfluidics-based lab-on-chip systems in DNA-based biosensing: an overview
    Dutse SW, Yusof NA
    Sensors (Basel), 2011;11(6):5754-68.
    PMID: 22163925 DOI: 10.3390/s110605754
    Microfluidics-based lab-on-chip (LOC) systems are an active research area that is revolutionising high-throughput sequencing for the fast, sensitive and accurate detection of a variety of pathogens. LOCs also serve as portable diagnostic tools. The devices provide optimum control of nanolitre volumes of fluids and integrate various bioassay operations that allow the devices to rapidly sense pathogenic threat agents for environmental monitoring. LOC systems, such as microfluidic biochips, offer advantages compared to conventional identification procedures that are tedious, expensive and time consuming. This paper aims to provide a broad overview of the need for devices that are easy to operate, sensitive, fast, portable and sufficiently reliable to be used as complementary tools for the control of pathogenic agents that damage the environment.
    Matched MeSH terms: Nanotechnology/methods
  19. Fulltext Synthesis of nanocrystalline SnO(x) (x = 1-2) thin film using a chemical bath deposition method with improved deposition time, temperature and pH
    Ebrahimiasl S, Yunus WM, Kassim A, Zainal Z
    Sensors (Basel), 2011;11(10):9207-16.
    PMID: 22163690 DOI: 10.3390/s111009207
    Nanocrystalline SnO(x) (x = 1-2) thin films were prepared on glass substrates by a simple chemical bath deposition method. Triethanolamine was used as complexing agent to decrease time and temperature of deposition and shift the pH of the solution to the noncorrosive region. The films were characterized for composition, surface morphology, structure and optical properties. X-ray diffraction analysis confirms that SnO(x) thin films consist of a polycrystalline structure with an average grain size of 36 nm. Atomic force microscopy studies show a uniform grain distribution without pinholes. The elemental composition was evaluated by energy dispersive X-ray spectroscopy. The average O/Sn atomic percentage ratio is 1.72. Band gap energy and optical transition were determined from optical absorbance data. The film was found to exhibit direct and indirect transitions in the visible spectrum with band gap values of about 3.9 and 3.7 eV, respectively. The optical transmittance in the visible region is 82%. The SnO(x) nanocrystals exhibit an ultraviolet emission band centered at 392 nm in the vicinity of the band edge, which is attributed to the well-known exciton transition in SnO(x). Photosensitivity was detected in the positive region under illumination with white light.
    Matched MeSH terms: Nanotechnology/methods*
  20. Sonochemical and sustainable synthesis of graphene-gold (G-Au) nanocomposites for enzymeless and selective electrochemical detection of nitric oxide
    Geetha Bai R, Muthoosamy K, Zhou M, Ashokkumar M, Huang NM, Manickam S
    Biosens Bioelectron, 2017 Jan 15;87:622-629.
    PMID: 27616288 DOI: 10.1016/j.bios.2016.09.003
    In this study, a sonochemical approach was utilised for the development of graphene-gold (G-Au) nanocomposite. Through the sonochemical method, simultaneous exfoliation of graphite and the reduction of gold chloride occurs to produce highly crystalline G-Au nanocomposite. The in situ growth of gold nanoparticles (AuNPs) took place on the surface of exfoliated few-layer graphene sheets. The G-Au nanocomposite was characterised by UV-vis, XRD, FTIR, TEM, XPS and Raman spectroscopy techniques. This G-Au nanocomposite was used to modify glassy carbon electrode (GCE) to fabricate an electrochemical sensor for the selective detection of nitric oxide (NO), a critical cancer biomarker. G-Au modified GCE exhibited an enhanced electrocatalytic response towards the oxidation of NO as compared to other control electrodes. The electrochemical detection of NO was investigated by linear sweep voltammetry analysis, utilising the G-Au modified GCE in a linear range of 10-5000μM which exhibited a limit of detection of 0.04μM (S/N=3). Furthermore, this enzyme-free G-Au/GCE exhibited an excellent selectivity towards NO in the presence of interferences. The synergistic effect of graphene and AuNPs, which facilitated exceptional electron-transfer processes between the electrolyte and the GCE thereby improving the sensing performance of the fabricated G-Au modified electrode with stable and reproducible responses. This G-Au nanocomposite introduces a new electrode material in the sensitive and selective detection of NO, a prominent biomarker of cancer.
    Matched MeSH terms: Nanotechnology/methods
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links