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https://www.readbyqxmd.com/read/28727443/plasmonic-thermal-decomposition-digestion-of-proteins-a-rapid-on-surface-protein-digestion-technique-for-mass-spectrometry-imaging
#1
Rong Zhou, Franco Basile
A method based on plasmon surface resonance absorption and heating was developed to perform a rapid on-surface protein thermal decomposition and digestion suitable for imaging MS and/or profiling. This photo-thermal process or plasmonic thermal decomposition/digestion (plasmonic-TDD) method incorporates a continuous wave (CW) laser excitation and gold nanoparticles (Au-NPs) to induce known thermal decomposition reactions that cleave peptides and proteins specifically at the C-terminus of aspartic acid and at the N-terminus of cysteine...
July 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28727434/ellipsometry-of-colloidal-solutions-new-experimental-setup-and-application-to-metallic-colloids
#2
Yann Battie, Michel Stchakovsky, Aotmane En Naciri, Suzanna Akil, Nouari Chaoui, Laurent Broch
An ellipsometric cell is developed to simultaneously determine the shape distribution, the volume fraction, and the complex refractive index of gold and silver colloids. Simulation reveals that this cell drastically improves the detection limit of ellipsometry. Indeed, Ag and Au nanoparticles (NPs) are detected at the ppmv level. We demonstrate that the NPs shape distribution can be estimated from ellipsometric measurements by analyzing them with a shape distributed effective medium theory (SDEMT). The obtained distributions from ellipsometry are in agreement with those deduced from transmission electron microcopy (TEM)...
July 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28727432/controlled-functionalisation-of-gold-nanoparticles-with-mixtures-of-calix-4-arenes-revealed-by-infra-red-spectroscopy
#3
Hennie Valkenier, Volodymyr Malytskyi, Pascale Blond, Maurice Retout, Alice Mattiuzzi, Jonathan Goole, Vincent Raussens, Ivan Jabin, Gilles Bruylants
Labile ligands such as thiols and carboxylates are commonly used to functionalise AuNPs, though little control over the composition is possible when mixtures of ligands are used. It was shown recently that robustly functionalised AuNPs can be obtained through the reductive grafting of calix[4]arenes bearing diazonium groups on the large rim. Here, we report a calix[4]arene-tetra-diazonium decorated by four oligo(ethylene glycol) chains on the small rim, which upon grafting gave AuNPs with excellent stability thanks to the C-Au bonds...
July 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28726968/evaluation-of-spectral-photon-counting-computed-tomography-k-edge-imaging-for-determination-of-gold-nanoparticle-biodistribution-in-vivo
#4
Salim Si-Mohamed, David P Cormode, Daniel Bar-Ness, Monica Sigovan, Pratap C Naha, Jean-Baptiste Langlois, Lara Chalabreysse, Philippe Coulon, Ira Blevis, Ewald Roessl, Klaus Erhard, Loic Boussel, Philippe Douek
Spectral photon counting computed tomography (SPCCT) is an emerging medical imaging technology. SPCCT scanners record the energy of incident photons, which allows specific detection of contrast agents due to measurement of their characteristic X-ray attenuation profiles. This approach is known as K-edge imaging. Nanoparticles formed from elements such as gold, bismuth or ytterbium have been reported as potential contrast agents for SPCCT imaging. Furthermore, gold nanoparticles have many applications in medicine, such as adjuvants for radiotherapy and photothermal ablation...
July 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28726315/biomineralization-of-gold-by-mucor-plumbeus-the-progress-in-understanding-the-mechanism-of-nanoparticles-formation
#5
Irena Maliszewska, Włodzimierz Tylus, Izabela Pawlaczyk-Graja, Wojciech Pusz, Anna Baturo-Cieśniewska, Jacek Chęcmanowski, Bogdan Szczygieł
This contribution describes the deposition of gold nanoparticles by microbial reduction of Au(III) ions using the mycelium of Mucor plumbeus. Biosorption as the major mechanism of Au(III) ions binding by the fungal cells and the reduction of them to the form of Au(0) on/in the cell wall, followed by the transportation of the synthesized gold nanoparticles to the cytoplasm, is postulated. The probable mechanism behind the reduction of Au(III) ions is discussed, leading to the conclusion that this process is non enzymatic one...
July 20, 2017: Biotechnology Progress
https://www.readbyqxmd.com/read/28726079/bilirubin-enzyme-biosensor-potentiality-and-recent-advances-towards-clinical-bioanalysis
#6
REVIEW
Vinita Hooda, Anjum Gahlaut, Ashish Gothwal, Vikas Hooda
Bilirubin detection plays a major role in healthcare. Its high concentration in human serum is lethal and must be determined accurately. Clinically, it is vital for assessing patients with deleterious health conditions such as jaundice or icterus, hepatitis, mental disorders, cerebral palsy and brain damage especially in the case of neonates. In evaluating the drawbacks regarding the conventional methodology of bilirubin detection, there is need for a superior analytical tool. Bilirubin oxidase (BOx)-based sensors have been designed for the ultrasensitive analysis of bilirubin and quality deliverance of treatment and this review highlights the different mechanisms of bilirubin detection using different modified electrodes...
July 19, 2017: Biotechnology Letters
https://www.readbyqxmd.com/read/28725884/an-enzyme-mediated-competitive-colorimetric-sensor-based-on-au-ag-bimetallic-nanoparticles-for-highly-sensitive-detection-of-disease-biomarkers
#7
Binfeng Yin, Wenshu Zheng, Mingling Dong, Wenbo Yu, Yiping Chen, Sang Woo Joo, Xingyu Jiang
We developed a competitive colorimetric nanosensor based on Au@Ag bimetallic nanoparticles for the detection of interleukin-6 (IL-6) in clinical samples. Antibody-conjugated magnetic nanoparticles (MNPs) and polystyrene (PS) microparticles conjugated with both catalase and a secondary antibody can form sandwich structures that enable one-step target enrichment and separation. The catalase on the surface of the PS can catalyze the hydrolysis of hydrogen peroxide (H2O2) to regulate the deposition of Ag(+) on the surface of gold nanoparticles (AuNPs), and forms different sizes and amounts of Au@Ag bimetallic nanoparticles (Au@AgNPs) which produce a distinct color signal for readout with the naked eye...
July 20, 2017: Analyst
https://www.readbyqxmd.com/read/28724927/dual-functionality-nanobioconjugates-targeting-intracellular-bacteria-in-cancer-cells-with-enhanced-antimicrobial-activity
#8
Rohini Singh, Smita Patil, Neetu Singh, Shalini Gupta
Bacterial drug resistance has emerged as a serious global threat mandating the development of novel methodologies that allow facile modulation of antimicrobial action in a controlled fashion. Conjugating antibiotics to nanoparticles helps to meet this goal by increasing the drug's overall avidity, bioavailability and easier internalisation into mammalian cells, targeting bacteria that otherwise escape antibacterial action by host cell-localisation. We used polymyxin B sulfate (PMB) and sushi peptide as model drugs against Gram-negative bacteria and established their enhanced antimicrobial activity on Escherichia coli (E...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28724260/pleuropterus-multiflorus-hasuo-mediated-straightforward-eco-friendly-synthesis-of-silver-gold-nanoparticles-and-evaluation-of-their-anti-cancer-activity-on-a549-lung-cancer-cell-line
#9
Verónica Castro-Aceituno, Ragavendran Abbai, Seong Soo Moon, Sungeun Ahn, Ramya Mathiyalagan, Yu-Jin Kim, Yeon-Ju Kim, Deok Chun Yang
Pleuropterus multiflorus (Hasuo) is a widely used medicinal plant in Korea and China for treating amnesia, isnomia, heart throbbing etc. With the constructive idea of promoting the wide-spread usage of P. multiflorus, we propose its indirect usage in the form of biologically active silver (Pm-AgNPs) and gold nanoparticles (Pm-AuNPs). The synthesized nanoparticles were predominantly spherical, crystalline with the Z-average hydrodynamic diameter of 274.8nm and 104.8nm respectively. Also, proteins and phenols were identified as the major players involved in their synthesis and stability...
July 15, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28723583/label-free-high-resolution-3-d-imaging-of-gold-nanoparticles-inside-live-cells-using-optical-diffraction-tomography
#10
Doyeon Kim, Nuri Oh, Kyoohyun Kim, SangYun Lee, Chan-Gi Pack, Ji-Ho Park, YongKeun Park
Delivery of gold nanoparticles (GNPs) into live cells has high potentials, ranging from molecular-specific imaging, photodiagnostics, to photothermal therapy. However, studying the long-term dynamics of cells with GNPs using conventional fluorescence techniques suffers from phototoxicity and photobleaching. Here, we present a method for 3-D imaging of GNPs inside live cells exploiting refractive index (RI) as imaging contrast. Employing optical diffraction tomography, 3-D RI tomograms of live cells with GNPs are precisely measured for an extended period with sub-micrometer resolution...
July 16, 2017: Methods: a Companion to Methods in Enzymology
https://www.readbyqxmd.com/read/28723182/cross-linked-gold-nanoparticle-membrane-resonators-as-microelectromechanical-vapor-sensors
#11
Hendrik Schlicke, Malte Behrens, Clemens J Schröter, Gregor T Dahl, Hauke Hartmann, Tobias Vossmeyer
We report a novel approach for the detection of volatile compounds employing electrostatically driven drumhead resonators as sensing elements. The resonators are based on freestanding membranes of alkanedithiol cross-linked gold nanoparticles (GNPs), which are able to sorb analytes from the gas phase. Under reduced pressure, the fundamental resonance frequency of a resonator is continuously monitored while the device is exposed to varying partial pressures of toluene, 4-methylpentan-2-one, 1-propanol, and water...
April 28, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723162/ultrasensitive-detection-of-cancer-prognostic-mirna-biomarkers-based-on-surface-plasmon-enhanced-light-scattering
#12
Chih-Tsung Yang, Mohammad Pourhassan-Moghaddam, Lin Wu, Ping Bai, Benjamin Thierry
The development of simple yet ultrasensitive biosensing approaches for the detection of cancer prognostic microRNA is an important step toward their successful clinical implementation. We demonstrate the relevance for the detection of circulating miRNA of a novel signal amplification scheme based on surface plasmon resonance enhanced light scattering (SP-LS). In addition to experimental optimization carried out using gold nanoparticle (AuNP) tags conjugated with a monoclonal antibody with high affinity for RNA*DNA hybrid duplexes, simulation modeling was conducted to obtain insights about SP-LS biosensing...
May 26, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723144/inflection-point-of-the-localized-surface-plasmon-resonance-peak-a-general-method-to-improve-the-sensitivity
#13
Peng Chen, Nhung Thi Tran, Xinglin Wen, Qihua Xiong, Bo Liedberg
The shift of the localized surface plasmon resonance (LSPR) spectrum is widely used in bio- and chemical sensing. Traditionally, the shift is monitored at the peak maximum of the extinction spectrum. We demonstrate that the inflection point at the long wavelength side of the peak maximum shows better refractive index sensitivity than the peak maximum. A consistent improvement in bulk refractive index sensitivity of 18-55% is observed for six different nanoparticles such as spherical particles of different sizes, nanostar and nanorods with different aspect ratios...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723143/an-ultrasensitive-plasmonic-nanosensor-for-aldehydes
#14
Meng Li, Lei Shi, Tao Xie, Chao Jing, Guangli Xiu, Yi-Tao Long
Glucose is the most common but important aldehyde, and it is necessary to create biosensors with high sensitivity and anti-interference to detect it. Under the existence of silver ions and aldehyde compounds, single gold nanoparticles and freshly formed silver atoms could respectively act as core and shell, which finally form a core-shell structure. By observing the reaction between glucose and Tollens' reagent, metallic silver was found to be reduced on the surface of gold nanoparticles and formed Au@Ag nanoparticles that lead to a direct wavelength shift...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723139/sensitive-cytokine-assay-based-on-optical-fiber-allowing-localized-and-spatially-resolved-detection-of-interleukin-6
#15
Guozhen Liu, Kaixin Zhang, Annemarie Nadort, Mark R Hutchinson, Ewa M Goldys
We demonstrated a cytokine detection device based on gold nanoparticle modified silica optical fiber for the monitoring of locally variable cytokine interleukin-6 (IL-6) concentrations using a sandwich immunoassay scheme. The fiber is designed to be introduced into an intrathecal catheter with micrometer-sized holes drilled along its length to enable fluid exchange between the outside and inside of the catheter. An exposed optical fiber (diameter 125 μm) modified with a layer of gold nanoparticles was functionalized with the IL-6 capture antibody to form the sensing interface...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723090/transformative-heterointerface-evolution-and-plasmonic-tuning-of-anisotropic-trimetallic-nanoparticles
#16
Mouhong Lin, Gyeong-Hwan Kim, Jae-Ho Kim, Jeong-Wook Oh, Jwa-Min Nam
Multi-component nanoparticles that incorporate multiple nano-crystal domains into a single particle represent an important class of material with highly tailorable structures and properties. The controlled synthesis of multi-component NPs with 3 or more components with the desired structure, particularly aniso-tropic structures, and property is, however, highly challenging. Here, we developed a polymer and galvanic replacement reac-tion-based transformative heterointerface evolution (THE) method to form and tune gold-copper-silver multi-metallic ani-sotropic nanoparticles (MAPs) with well-defined configurations, including structural order, uniformity and junction geometry, giving rise to extraordinarily high tunability in the structural design, synthesis and optical property of tri-metallic plasmonic nanoantenna structures...
July 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28722415/dramatic-modification-of-coupled-plasmon-resonances-following-exposure-to-electron-beams
#17
Haixu Leng, Brian Szychowski, Marie Christine Daniel, Matthew Pelton
Studies of the plasmon resonances in individual and coupled metal nanoparticles often involve imaging of the nanostructures of interest in an electron microscope. Here, we show that this process can dramatically modify the optical scattering spectra of coupled gold-nanorod / gold-nanosphere dimers. Exposure to the electron beam modifies the nature of coupling between the nanoparticles, due to the thin, partially conductive carbonaceous layer that deposits onto the particles during imaging. Neglecting the effect of this layer can lead to misinterpretation of experimental results, particularly for measurements intended to probe quantum-mechanical effects in plasmon coupling...
July 19, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28722328/manipulation-of-inorganic-atomic-layer-networks-by-solution-phase-co-assembly
#18
Yajiao Hao, Lin Yu, Chuying Dai, Song Li, Yang Yu, Bo Ju, Minjie Li, Sean Xiao-An Zhang
Homogeneous two-dimensional (2D) lamellar assemblies of Au(I)-thiolate coordination polymer (ATCP) have been achieved with double-ligand co-assembly. The orbital levels and the bandgap of the 2D Au(I)-S network in the centre of the lamellae can be continuously tuned by the capping ligands on both sides, demonstrating a new type of inorganic-organic composite semiconductor, whose band structure can be easily tuned by low-temperature solution-phase co-assembly. What's more, the chemical reactivity of these ATCP co-assemblies is also proved to be largely dependent on the organic substituents, showing well-tunable transforming rates to gold nanoparticles...
July 18, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28722270/retraction-gold-nanoparticles-immobilized-on-electrospun-titanium-dioxide-nanofibers-for-catalytic-reduction-of-4-nitrophenol
#19
Halit Cavusoglu, Burak Z Buyukbekar, Huseyin Sakalak, Sebastian Kohsakowski
No abstract text is available yet for this article.
July 19, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28721722/pillar-5-arene-based-supramolecular-plasmonic-thin-films-for-label-free-quantitative-and-multiplex-sers-detection
#20
Verónica Montes García, Borja Gómez-González, Diego M Solís, Jose M Taboada, Norman Jiménez Otero, Jacobo de Uña-Álvarez, Fernando Obelleiro, Luis García-Río, Jorge Perez-Juste, Isabel Pastoriza-Santos
Novel plasmonic thin films based on electrostatic layer-by-layer (LbL) deposition of citrate-stabilized Au nanoparticles (NPs) and ammonium pillar[5]arene (AP[5]A) has been developed. The supramolecular-induced LbL assembly of the plasmonic nanoparticles yields to the formation of controlled hot-spots with uniform interparticle distances. At the same time this strategy allows to modulate the density and dimensions of the Au aggregates, and therefore the optical response, on the thin film with the number of AuNP-AP[5]A deposition cycles...
July 19, 2017: ACS Applied Materials & Interfaces
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