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https://www.readbyqxmd.com/read/29763288/quantum-dot-fullerene-based-molecular-beacon-nanosensors-for-rapid-highly-sensitive-nucleic-acid-detection
#1
Ye Liu, Akash Kannegulla, Bo Wu, Li-Jing Cheng
Spherical fullerene (C60 ) can quench the fluorescence of a quantum dot (QD) through energy transfer and charge transfer processes, with the quenching efficiency regulated by the number of proximate C60 on each QD. With the quenching property and its small size compared with other nanoparticle-based quenchers, it is advantageous to group a QD reporter and multiple C60 -labeled oligonucleotide probes to construct a molecular beacon (MB) probe for sensitive, robust nucleic acid detection. We demonstrated a rapid, high-sensitivity DNA detection method using the nanosensors composed of QD-C60 based MBs carried by magnetic nanoparticles (MNPs)...
May 15, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29761206/imaging-of-oxygen-and-hypoxia-in-cell-and-tissue-samples
#2
REVIEW
Dmitri B Papkovsky, Ruslan I Dmitriev
Molecular oxygen (O2 ) is a key player in cell mitochondrial function, redox balance and oxidative stress, normal tissue function and many common disease states. Various chemical, physical and biological methods have been proposed for measurement, real-time monitoring and imaging of O2 concentration, state of decreased O2 (hypoxia) and related parameters in cells and tissue. Here, we review the established and emerging optical microscopy techniques allowing to visualize O2 levels in cells and tissue samples, mostly under in vitro and ex vivo, but also under in vivo settings...
May 14, 2018: Cellular and Molecular Life Sciences: CMLS
https://www.readbyqxmd.com/read/29750866/luminescent-gold-nanocluster-decorated-polymeric-hybrid-particles-with-assembly-induced-emission
#3
Mathew T Hembury, Nataliia Beztsinna, Hamed Asadi, Joep van den Dikkenberg, Johannes D Meeldijk, Wim E Hennink, Tina Vermonden
Ultrasmall gold atom clusters (< 2 nm in diameter) or gold nanoclusters exhibit emergent photonic properties (near-infrared absorption and emission) compared to larger plasmonic gold particles, due to the significant quantization of their conduction band. While single gold nanoclusters properties and applications are being increasingly investigated, little is still known about their behaviour and properties when assembled into suprastructures and even less studies are investigating their use for biomedical applications...
May 11, 2018: Biomacromolecules
https://www.readbyqxmd.com/read/29747508/mercury-speciation-with-fluorescent-gold-nanocluster-as-a-probe
#4
Jian-Yu Yang, Ting Yang, Xiao-Yan Wang, Ming-Li Chen, Yong-Liang Yu, Jian-Hua Wang
Fluorescent nanoparticles are widely used for sensing biologically significant species. However, it is rarely reported for the discrimination or speciation of metal species. In this work, we report for the first time the speciation of mercury (Hg2+ ) and methylmercury (CH3 Hg+ ) by taking advantage of the fluorescence feature of folic acid-capped gold nanoclusters (FA-AuNCs). FA-Au NCs exhibit an average size of 2.08±0.15 nm and a maximum emission at λex /λem = 280/440 nm with a quantum yield of 27.3%. It is interesting that Hg2+ causes a significant quench on the fluorescence of FA-Au NCs, whereas CH3 Hg+ leads to a remarkable fluorescence enhancement...
May 11, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29737984/environmentally-responsive-plasmonic-nanoassemblies-for-biosensing
#5
Xiaoling Wu, Changlong Hao, Jatish Kumar, Hua Kuang, Nicholas A Kotov, Luis M Liz-Marzán, Chuanlai Xu
Assemblies of plasmonic nanoparticles enable new modalities for biosensing. Engineered superstructures from metal nanoparticles can enhance the plasmon resonances and chiroptical activity of nanoscale dispersions. Such phenomena are keys to the fabrication of highly sensitive, selective and fast-responding detection platforms, making them promising candidates for clinical applications. This tutorial review summarizes and discusses recent advances in this area. The topics covered in the review include the basic strategies adopted for assembly and engineering of plasmonic nanoparticles, optical properties of the assembled nanostructures and their applications to both in vitro and in vivo detection of biological compounds...
May 8, 2018: Chemical Society Reviews
https://www.readbyqxmd.com/read/29721089/high-discrimination-factor-nanosensor-based-on-tetrahedral-dna-nanostructures-and-gold-nanoparticles-for-detection-of-mirna-21-in-live-cells
#6
Shulian Bai, Bangtian Xu, Yongcan Guo, Juhui Qiu, Wen Yu, Guoming Xie
While detection of microRNA with or without signal amplification is highly informative, nanosensors with high specificity for cell-specific RNA detection are rare. Methods: In this study, a tetrahedral DNA nanostructure (TDN) with a specific function was combined with gold nanoparticles (Au-NP) possessing fluorescence quenching effects and a large surface area to fabricate a fluorescence resonance energy transfer based nanosensor (Au-TDNN). The presence of miR-21 (target) can separate the fluorescent dye-labeled detection probe on Au-TDNNs from Au-NPs, which separates the donor and acceptor, thus inducing an intensive fluorescence signal...
2018: Theranostics
https://www.readbyqxmd.com/read/29718039/selectively-arranged-single-wire-based-nanosensor-array-systems-for-gas-monitoring
#7
O Chmela, J Sadílek, G Domènech-Gil, J Samà, J Somer, R Mohan, A Romano-Rodriguez, J Hubálek, S Vallejos
Gas nanosensors, comprised of arrays of nanoelectrodes with finger-widths of ∼100 nm developed by electron beam lithography and aerosol assisted chemical vapor deposited non-functionalized and Pt-functionalized tungsten oxide nanowires (<100 nm) subsequently integrated across the pairs of electrodes via the dielectrophoresis method, are developed in this work. The functionality of these devices is validated towards various concentrations of NO2 and C2H5OH. The results demonstrate reproducible and consistent responses with better sensitivity and partial selectivity for the non-functionalized systems to NO2, as opposed to the Pt-functionalized systems, which display better sensing properties towards C2H5OH with a loss of response to NO2...
May 2, 2018: Nanoscale
https://www.readbyqxmd.com/read/29713073/calcium-dependent-molecular-fmri-using-a-magnetic-nanosensor
#8
Satoshi Okada, Benjamin B Bartelle, Nan Li, Vincent Breton-Provencher, Jiyoung J Lee, Elisenda Rodriguez, James Melican, Mriganka Sur, Alan Jasanoff
Calcium ions are ubiquitous signalling molecules in all multicellular organisms, where they mediate diverse aspects of intracellular and extracellular communication over widely varying temporal and spatial scales 1 . Though techniques to map calcium-related activity at a high resolution by optical means are well established, there is currently no reliable method to measure calcium dynamics over large volumes in intact tissue 2 . Here, we address this need by introducing a family of magnetic calcium-responsive nanoparticles (MaCaReNas) that can be detected by magnetic resonance imaging (MRI)...
April 30, 2018: Nature Nanotechnology
https://www.readbyqxmd.com/read/29710806/self-reference-refractive-index-sensor-based-on-independently-controlled-double-resonances-in-side-coupled-u-shaped-resonators
#9
Xiaobin Ren, Kun Ren, Chengguo Ming
A plasmonic, refractive, index nanosensor is investigated theoretically and numerically in two U-shaped cavities side-coupled to a metal⁻dielectric⁻metal (MDM) waveguide. A transparency window between two transmission dips is observed. The physical origin of the transmission phenomenon is revealed by mapping the magnetic field distribution. Independent double resonances are realized through the proposed design. Double resonances showed diverse responses to the variations of the structural dimensions. In particular, they presented different dependences on a refraction index of the medium in an individual resonator...
April 28, 2018: Sensors
https://www.readbyqxmd.com/read/29708240/a-facile-graphene-oxide-based-fluorescent-nanosensor-for-the-in-situ-turn-on-detection-of-telomerase-activity
#10
Li Zhang, Jie Peng, Ming-Fang Hong, Jia-Qing Chen, Ru-Ping Liang, Jian-Ding Qiu
A facile and sensitive method for the quantitative detection of telomerase and in situ imaging of intracellular telomerase is developed by using a graphene oxide (GO)-based fluorescent nanosensor. The nanosensor consists of a fluorescent DNA (P1) adsorbed on the GO surface. Here, GO serves not only as a fluorescence quencher but also as a carrier to successfully transport P1 into cancer cells as a signal reporter. P1 is a dye-labeled single-stranded DNA complementary to the telomeric repeated sequence, and initially the combination of P1 and GO exhibits minimal background fluorescence...
April 30, 2018: Analyst
https://www.readbyqxmd.com/read/29702581/on-the-nature-of-energy-feasible-wireless-nanosensor-networks
#11
Sebastian Canovas-Carrasco, Antonio-Javier Garcia-Sanchez, Joan Garcia-Haro
Electromagnetic nanocommunications, understood as the communication between electronic nanoscale devices through electromagnetic waves in the terahertz band, has attracted increasing attention in recent years. In this regard, several solutions have already been proposed. However, many of them do not sufficiently capture the significance of the limitations in nanodevice energy-gathering and storing capacity. In this paper, we address key factors affecting the energy consumption of nanodevices, highlighting the effect of the communication scheme employed...
April 27, 2018: Sensors
https://www.readbyqxmd.com/read/29699653/carbon-dots-based-dual-emission-silica-nanoparticles-as-ratiometric-fluorescent-probe-for-nitrite-determination-in-food-samples
#12
Guoqiang Xiang, Yule Wang, Heng Zhang, Huanhuan Fan, Lu Fan, Lijun He, Xiuming Jiang, Wenjie Zhao
In this work, a simple and effective strategy for designing a ratiometric fluorescent nanosensor was described. A carbon dots (CDs) based dual-emission nanosensor for nitrite was prepared by coating the CDs on to dye-doped silica nanoparticles. Dual-emission silica nanoparticles fluorescence was quenched in sulfuric acid using potassium bromate (KBrO3 ). The nitrite present catalyzed the KBrO3 oxidation, resulting in ratiometric fluorescence response of the dual-emission silica nanoparticles. Several important parameters affecting the performance of the nanosensor were investigated...
September 15, 2018: Food Chemistry
https://www.readbyqxmd.com/read/29678113/water-adsorption-by-a-sensitive-calibrated-gold-plasmonic-nanosensor
#13
Benjamin Demirdjian, Frédéric Bedu, Alain Ranguis, Igor Ozerov, Claude R Henry
We demonstrate in this work that using nanoplasmonic sensing it is possible to follow the adsorption/desorption of water molecules on gold nanodisks nanofabricated by electron beam lithography. This quantitative method is highly sensitive allowing the detection of a few hundredths of adsorbed monolayers. Disk parameters (height, diameter, inter-disk distance) have been optimized after finite-difference time-domain (FDTD) simulations in order to obtain the best localized surface plasmon resonance (LSPR) signal-to-noise ratio...
April 20, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29677441/homologous-mirna-analyses-using-a-combinatorial-nanosensor-array-with-two-dimensional-nanoparticles
#14
Mustafa Salih Hizir, Nidhi Nandu, Mehmet Veysel Yigit
A novel combinatorial nanosensor array for miRNA analyses was assembled using the intrinsic non-covalent interactions of unmodified two-dimensional nanoparticles. Discrimination of nine miRNA analogs with as little as a single nucleotide difference was demonstrated under four hours. All nine targets were identified simultaneously with 95% confidence. The developed nanotechnology offered identification and quantification of unknown targets with unknown concentration. Discrimination of target mixtures from low-to-high ratios was demonstrated...
April 20, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29675550/large-area-gold-nanohole-arrays-fabricated-by-one-step-method-for-surface-plasmon-resonance-biochemical-sensing
#15
Huijie Qi, Lihong Niu, Jie Zhang, Jian Chen, Shujie Wang, Jingjing Yang, Siyi Guo, Tom Lawson, Bingyang Shi, Chunpeng Song
Surface plasmon resonance (SPR) nanosensors based on metallic nanohole arrays have been widely reported to detect binding interactions in biological specimens. A simple and effective method for constructing nanoscale arrays is essential for the development of SPR nanosensors. In this work, we report a one-step method to fabricate nanohole arrays by thermal nanoimprinting in the matrix of IPS (Intermediate Polymer Stamp). No additional etching process or supporting substrate is required. The preparation process is simple, time-saving and compatible for roll-to-roll process, potentially allowing mass production...
April 1, 2018: Science China. Life Sciences
https://www.readbyqxmd.com/read/29675469/noninvasive-ovarian-cancer-biomarker-detection-via-an-optical-nanosensor-implant
#16
Ryan M Williams, Christopher Lee, Thomas V Galassi, Jackson D Harvey, Rachel Leicher, Maria Sirenko, Madeline A Dorso, Janki Shah, Narciso Olvera, Fanny Dao, Douglas A Levine, Daniel A Heller
Patients with high-grade serous ovarian carcinoma (HGSC) exhibit poor 5-year survival rates, which may be significantly improved by early-stage detection. The U.S. Food and Drug Administration-approved biomarkers for HGSC-CA-125 (cancer antigen 125) and HE4 (human epididymis protein 4)-do not generally appear at detectable levels in the serum until advanced stages of the disease. An implantable device placed proximal to disease sites, such as in or near the fallopian tube, ovary, uterine cavity, or peritoneal cavity, may constitute a feasible strategy to improve detection of HGSC...
April 2018: Science Advances
https://www.readbyqxmd.com/read/29675180/single-quantum-dot-based-nanosensor-for-sensitive-detection-of-5-methylcytosine-at-both-cpg-and-non-cpg-sites
#17
Zi-Yue Wang, Li-Juan Wang, Qianyi Zhang, Bo Tang, Chun-Yang Zhang
DNA methylation is an important epigenetic modification in human genomes. Herein, we develop a single quantum dot (QD)-based nanosensor for sensitive detection of DNA methylation at both CpG and non-CpG sites using tricyclic ligation chain reaction (LCR)-mediated QD-based fluorescence resonance energy transfer (FRET). We design two sets of DNA probes (X and Y, X' and Y') for methylated DNA assay. In the presence of thermostable DNA ligase, probes X and Y may adjacently hybridize with the methylated DNA to obtain the ligated XY products which may function as the templates for probes X' and Y' to generate the X'Y' products...
February 7, 2018: Chemical Science
https://www.readbyqxmd.com/read/29660681/etching-dependent-fluorescence-quenching-of-ag-dielectric-au-three-layered-nanoshells-the-effect-of-inner-ag-nanosphere
#18
Jian Zhu, Zai-Jie Xu, Guo-Jun Weng, Jing Zhao, Jian-Jun Li, Jun-Wu Zhao
In this report, Ag-dielectric-Au three-layered nanoshells with controlled inner core size were synthesized. The fluorescence emission of the rhodamine 6G (R6G) could be quenched by the three-layered nanoshells distinctly. What's more, the fluorescence quenching efficiency could be further improved by tuning the etching of inner Ag nanosphere. The maximum fluorescence quenching efficiency is obtained when the separate layer just appears between the inner Ag core and the outer Au shell. Whereas the fluorescence quenching efficiency is weakened when no gaps take place around the inner Ag core or the separate layer is too thick and greater than 13nm...
April 10, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29652477/targeted-nanoparticles-for-selective-marking-of-neuromuscular-junctions-and-ex-vivo-monitoring-of-endogenous-acetylcholine-hydrolysis
#19
Alsu R Mukhametshina, Svetlana V Fedorenko, Alexey M Petrov, Guzel F Zakyrjanova, Konstantin A Petrov, Leniz F Nurullin, Irek R Nizameev, Asiya R Mustafina, Oleg G Sinyashin
The present work for the first time introduces nanosensors for luminescent monitoring of acetylcholinesterase (AChE)-catalyzed hydrolysis of endogenous acetylcholine (AСh) released in neuromuscular junctions of isolated muscles. The sensing function results from the quenching of Tb(III)-centered luminescence due to proton-induced degradation of luminescent Tb(III) complexes doped into silica nanoparticles (SNs, 23 nm), when acetic acid is produced from the enzymatic hydrolysis of ACh. The targeting of the silica nanoparticles by α-bungarotoxin was used for selective staining of the synaptic space in the isolated muscles by the nanosensors...
April 13, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29652127/optical-probes-for-neurobiological-sensing-and-imaging
#20
Eric H Kim, Gregory Chin, Guoxin Rong, Kira E Poskanzer, Heather A Clark
Fluorescent nanosensors and molecular probes are next-generation tools for imaging chemical signaling inside and between cells. Electrophysiology has long been considered the gold standard in elucidating neural dynamics with high temporal resolution and precision, particularly on the single-cell level. However, electrode-based techniques face challenges in illuminating the specific chemicals involved in neural cell activation with adequate spatial information. Measuring chemical dynamics is of fundamental importance to better understand synergistic interactions between neurons as well as interactions between neurons and non-neuronal cells...
April 13, 2018: Accounts of Chemical Research
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