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Briliant Adhi Prabowo, Robert Y L Wang, Muhammad Khari Secario, Po-Ting Ou, Azharul Alom, Jia-Jung Liu, Kou-Chen Liu
This study presents the first report on a label-free detection and rapid quantification method for human enterovirus 71 (EV71) using a portable surface plasmon resonance (SPR) system. The SPR sensor instrument was configured to run on low power in a miniaturized platform to improve the device portability for a wider application both in laboratories and in the field. A color tunable organic light emitting diode in red spectrum was attached on a trapezoidal prism for the disposable light source module. The SPR signal processing using integration area under the reflectivity curve is applied for optimum signal to noise ratio (SNR) enhancement...
January 21, 2017: Biosensors & Bioelectronics
Javad Khodaveisi, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, Dariush Saberi
A highly selective and sensitive colorimetric sensor for the determination of naproxen (NAP) based on the aggregation of the thiolated β-cyclodextrin (Tβ-CD) functionalized gold nanoparticles (Tβ-CD-Au NPs) in the presence of NAP and Zn(2+)is described. The hydrophobic end of NAP interacts with the immobilized Tβ-CD on the Au NPs and forms the complex of Tβ-CD:NAP while the Zn(2+) ions form a 1:2 complex of (NAP)2Zn with the carboxyl groups of NAP resulting in the aggregation of functionalized gold nanoparticles...
February 8, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Xian Shi, Nicolás Coca-López, Julia Janik, Achim Hartschuh
Tip-enhanced near-field Raman microscopy spectroscopy is a scanning probe technique that is capable of providing vibrational spectroscopic information on single nanoobjects and surfaces at (sub-) nanometer spatial resolution and high detection sensitivity. In this review, we first illustrate the physical principle of optical nanoantennas used in tip-enhanced near-field Raman microscopy and tip-enhanced Raman scattering (TERS) to efficiently couple light to Raman excitations on nanometer length scales. Although the antennas' electric near-field distributions are commonly understood to determine the spatial resolution, recent experiments showing subnanometer-resolved optical images put this understanding into question...
February 17, 2017: Chemical Reviews
Hao Li, Feng Qin, Zhiping Yang, Ximin Cui, Jianfang Wang, Lizhi Zhang
Selective organic transformation under mild conditions constitutes a challenge in green chemistry, especially for alcohol oxidation, which typically requires environmentally unfriendly oxidants. Here, we report a new plasmonic catalyst of Au supported on BiOCl containing oxygen vacancies. It photocatalyzes selective benzyl alcohol oxidation with O2 under visible light through synergistic action of plasmonic hot electrons and holes. Oxygen vacancies on BiOCl facilitate the trapping and transfer of plasmonic hot electrons to adsorbed O2, producing •O2(‒) radicals, while plasmonic hot holes remaining on the Au surface mildly oxidize benzyl alcohol to corresponding carbon-centered radicals...
February 17, 2017: Journal of the American Chemical Society
David L Mack, Emiliano Cortés, Vincenzo Giannini, Peter Török, Tyler Roschuk, Stefan A Maier
The absorption process of an emitter close to a plasmonic antenna is enhanced due to strong local electromagnetic (EM) fields. The emission, if resonant with the plasmonic system, re-radiates to the far-field by coupling with the antenna via plasmonic states, whose presence increases the local density of states. Far-field collection of the emission of single molecules close to plasmonic antennas, therefore, provides mixed information of both the local EM field strength and the local density of states. Moreover, super-resolution localizations from these emission-coupled events do not report the real position of the molecules...
February 17, 2017: Nature Communications
R Britto Hurtado, M Cortez-Valadez, H Arizpe-Chávez, N S Flores-Lopez, Ramón A B Álvarez, M Flores-Acosta
Due to their physicochemical properties, metallic nanoalloys have potential applications in biomedicine, electrocatalysis and electrochemical sensors, among many other fields. New alternative procedures have emerged in order to reduce production costs and the use of toxic substances. In this study we present a novel low-toxicity synthesis method for the fabrication of nanowire networks (NWNs) and Ag-Au hollow nanospheres. The synthesis process is performed at room temperature without any sophisticated equipment, such as special cameras or furnaces, etc...
March 17, 2017: Nanotechnology
Aysa Rezabakhsh, Elahe Nabat, Mina Yousefi, Soheila Montazersaheb, Omid Cheraghi, Amir Mehdizadeh, Farzaneh Fathi, Ali Akbar Movassaghpour, Nasrin Maleki-Dizaji, Reza Rahbarghazi, Alireza Garjani
To date, many studies have been conducted to find out the underlying mechanisms of hyperglycemia-induced complications in diabetes mellitus, attributed to the cellular pathologies of different cells-especially endothelial cells. However, there are still many ambiguities and unresolved issues to be clarified. Here, we investigated the alteration in biophysical and biochemical properties in human umbilical vein endothelial cells exposed to a high-glucose concentration (30mM), comparable to glucose content in type 2 diabetes mellitus, over a course of 120 hours...
February 17, 2017: Cell Biochemistry and Function
Nibha Mishra, Lyndon Friedson, Geula Hanin, Uriya Bekenstein, Meshi Volovich, Estelle R Bennett, David S Greenberg, Hermona Soreq
MicroRNA (miR)-132 brain-to-body messages suppress inflammation by targeting acetylcholinesterase (AChE), but the target specificity of 3'-AChE splice variants and the signaling pathways involved remain unknown. Using surface plasmon resonance (SPR), we identified preferential miR-132 targeting of soluble AChE-R over synaptic-bound AChE-S, potentiating miR-132-mediated brain and body cholinergic suppression of pro-inflammatory cytokines. Inversely, bacterial lipopolysaccharide (LPS) reduced multiple miR-132 targets, suppressed AChE-S more than AChE-R and elevated inflammatory hallmarks...
February 17, 2017: Scientific Reports
A Bakhmachuk, O Gorbatiuk, A Rachkov, B Dons'koi, R Khristosenko, I Ushenin, V Peshkova, A Soldatkin
The developed surface plasmon resonance (SPR) biosensor based on the recombinant Staphylococcal protein A with an additional cysteine residue (SPA-Cys) used as a biorecognition component showed a good selectivity and sensitivity for the immunoglobulin detection. The developed biosensor with SPA-Cys-based bioselective element can also be used as a first step of immunosensor creation. The successful immobilization of SPA-Cys on the nanolayer gold sensor surface of the SPR spectrometer was performed. The efficiency of blocking nonspecific sorption sites on the sensor surface with milk proteins, gelatin, BSA, and HSA was studied, and a rather high efficiency of using gelatin was confirmed...
December 2017: Nanoscale Research Letters
Zhen Zhang, Wei Yu, Jing Wang, Dan Luo, Xuezhi Qiao, Xiaoyun Qin, Tie Wang
Surface-enhanced Raman scattering (SERS) is expected as a technique that even theoretically detected chemicals at the single molecule level by surface plasmon phenomena of noble metal nanostructures. Insensitivity of detecting Raman weak-intensity molecules and low adsorptivity of gaseous molecules on solid substrates are two main factors hindering the application of SERS in gas detectors. In this manuscript, we demonstrated an operational SERS strategy to detect gaseous Raman weak-intensity aldehydes that have been considered as a biomarker of lung cancer for abnormal content was measured in volatile organic compounds (VOCs) of lung cancer patients...
February 7, 2017: Analytical Chemistry
Richard Maceiczyk, Hisashi Shimizu, David Müller, Takehiko Kitamori, Andrew deMello
Sensitive detection and quantification of individual plasmonic nanoparticles is critical in a range of applications in the biological, nanomaterials, and analytical sciences. Although a wide range of techniques can be applied to the analysis of immobilized particles, high-throughput analysis of nanoscale species in flow is surprisingly underdeveloped. To address this shortcoming, we present an ultrasensitive, background-free technique based on the photothermal effect and termed differential detection photothermal interferometry (DDPI)...
February 7, 2017: Analytical Chemistry
Guangyu Qiu, Siu Pang Ng, Xiongyi Liang, Ning Ding, Xiangfeng Chen, Chi-Man Lawrence Wu
Using self-assembly gold nanoislands (SAM-AuNIs) functionalized by poly(m-phenylenediamine-co-aniline-2-sulfonic acid) (poly(mPD-co-ASA)) copolymer nanoparticles as specific receptors, a highly sensitive localized surface plasmon resonance (LSPR) optochemical sensor is demonstrated for detection of trace lead cation (Pb(II)) in drinking water. The copolymer receptor is optimized in three aspects: (1) mole ratio of mPD:ASA monomers, (2) size of copolymer nanoparticles, and (3) surface density of the copolymer...
February 7, 2017: Analytical Chemistry
Sweccha Joshi, Han Zuilhof, Teris A van Beek, Michel W F Nielen
A simplified coupling of surface plasmon resonance (SPR) immuno-biosensing with ambient ionization mass spectrometry (MS) was developed. It combines two orthogonal analysis techniques: the biosensing capability of SPR and the chemical identification power of high resolution MS. As a proof-of-principle, deoxynivalenol (DON), an important mycotoxin, was captured using an SPR gold chip containing an antifouling layer and monoclonal antibodies against the toxin and, after washing, the chip could be taken out and analyzed by direct spray MS of the biosensor chip to confirm the identity of DON...
February 7, 2017: Analytical Chemistry
Shaohua Xu, Wenjun Ouyang, Peisi Xie, Yi Lin, Bin Qiu, Zhenyu Lin, Guonan Chen, Longhua Guo
Gold nanoparticles (AuNPs) have been frequently utilized for the construction of diverse colorimetric biosensors. Normally, AuNPs with sharp edges could have better sensitivity. However, the poor monodipersity of AuNPs with sharp edges seriously confines their utility for colorimetric biosensing. Herein, we demonstrate the utility of highly uniform gold nanobipyramids (Au NBPs) for ultrasensitive colorimetric detection of H5N1 virus. The proposed method is based on the fact that alkaline phosphatase (ALP) could catalyze the decomposition of 4-aminophenyl phosphate (4-APP) to generate 4-aminophenol (4-AP), which would then reduce silver nitrate to metal silver and then deposited on Au NBPs...
February 7, 2017: Analytical Chemistry
Ming Xuan Gao, Hong Yan Zou, Yuan Fang Li, Cheng Zhi Huang
Plasmonic resonance energy transfer (PRET), which occurs between the plasmonic nanoparticles and organic dyes, has significant potential in target sensing chemistry owing to its sensitivity at the single nanoparticle level. In this contribution, by using AuNPs, which has localized surface plasmonic resonance light scattering (LSPR-LS) around 550 nm, as the donor of PRET, a general sensitive detecting strategy of ions were developed. Targets can specifically react with a ring-close structured rhodamine spirolactam, which was prepared from rhodamines in the presence of different primary amine wherein the option of the primary amine is up to the targets, forming ring-open structured rhodamine spirolactam with the strong absorption around 550 nm...
February 7, 2017: Analytical Chemistry
Yongmei Yin, Qiang Li, Sisi Ma, Huiqiao Liu, Bo Dong, Jie Yang, Dingbin Liu
We report a surprising discovery that Prussian blue (PB) can be employed as a highly sensitive and background-free resonant Raman reporter. Conventional Raman reporters show multiple spectral bands in the fingerprint region, which are generally overlapped with those from dominant endogenous biomolecules, and are thus difficult to be separated. Herein, we found that PB only possesses a strong and sharp single-band in the cellular Raman-silent region, where no Raman signals from biological species were observed...
February 7, 2017: Analytical Chemistry
Lucyano J A Macedo, Erin N Miller, Aric Opdahl
We have used temperature gradient surface plasmon resonance (SPR) measurements to quantitatively evaluate how the stability of different types of hybrids formed with DNA probes on surfaces is affected by probe spacing. SPR sensors with different average surface densities of probes were prepared by coadsorbing probes with lateral spacers strands comprised of phosphorothioated adenine nucleotides (A15*). Increasing the fraction of A15* spacers in the immobilization solution results in larger distances between probes on the sensor, determined here using a combination of SPR and X-ray photoelectron spectroscopy (XPS) measurements...
February 7, 2017: Analytical Chemistry
Ping Cao, Guifang Dou, Yuanguo Cheng, Jinjing Che
Most mechanistic studies on human immunodeficiency virus (HIV) peptide fusion inhibitors have focused on the interactions between fusion inhibitors and viral envelope proteins. However, the interactions of fusion inhibitors with viral membranes are also essential for the efficacy of these drugs. Here, we utilized surface plasmon resonance (SPR) technology to study the interactions between the HIV fusion inhibitor peptides sifuvirtide and enfuvirtide and biomembrane models. Sifuvirtide presented selectivity toward biomembrane models composed of saturated dipalmitoylphosphatidylcholine (DPPC) (32-fold higher compared with unsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine [POPC]) and sphingomyelin (SM) (31-fold higher compared with POPC), which are rigid compositions enriched in the HIV viral membrane...
2017: PloS One
Andrii Iurov, Godfrey Gumbs, Danhong Huang
We have numerically calculated electron exchange and correlation energies and dynamical polarization functions for recently discovered silicene, germanene and other buckled honeycomb lattices at various temperatures. We have compared the dependence of these energies on the chemical potential, field-induced gap and temperature and we have concluded that in many cases they behave qualitatively in a similar way, i.e. increasing with the doping, decreasing significantly at elevated temperatures, and displaying different dependences on the asymmetry gap at various temperatures...
February 16, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Arash Ahmadivand, Burak Gerislioglu, Raju Sinha, Mustafa Karabiyik, Nezih Pala
Capacitive coupling and direct shuttling of charges in nanoscale plasmonic components across a dielectric spacer and through a conductive junction lead to excitation of significantly different dipolar and charge transfer plasmon (CTP) resonances, respectively. Here, we demonstrate the excitation of dipolar and CTP resonant modes in metallic nanodimers bridged by phase-change material (PCM) sections, material and electrical characteristics of which can be controlled by external stimuli. Ultrafast switching (in the range of a few nanoseconds) between amorphous and crystalline phases of the PCM section (here Ge2Sb2Te5 (GST)) allows for designing a tunable plasmonic switch for optical communication applications with significant modulation depth (up to 88%)...
February 16, 2017: Scientific Reports
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