keyword
MENU ▼
Read by QxMD icon Read
search

Aptamers

keyword
https://www.readbyqxmd.com/read/28732346/multiplexed-aptasensor-for-simultaneous-detection-of-carcinoembryonic-antigen-and-mucin-1-based-on-metal-ion-electrochemical-labels-and-ru-nh3-6-3-electronic-wires
#1
Chao Ma, Haiyun Liu, Lina Zhang, Hao Li, Mei Yan, Xianrang Song, Jinghua Yu
In this paper, a dual-target electrochemical aptasensor has been developed for simultaneous detection of carcinoembryonic antigen and mucin-1 based on metal ion electrochemical labels and Ru(NH3)6(3+) electronic wires. When targets are present, the interaction between targets and their respective aptamers leads to the dissociation of double-strand DNA because the targets have higher affinity to its aptamer than the complementary strand. And the qualitative and quantitative analyses of the two targets are realized by the differential pulse voltammetry (DPV) peaks generated by metal ion electrochemical labels...
July 13, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28732094/surface-enhanced-raman-spectroscopy-competitive-binding-biosensor-development-utilizing-surface-modification-of-silver-nanocubes-and-a-citrulline-aptamer
#2
Brian M Walton, George W Jackson, Nicolaas Deutz, Gerard Cote
No abstract text is available yet for this article.
July 1, 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28731107/a-fluorescent-turn-on-nanoprobe-for-simultaneous-visualization-of-dual-targets-involved-in-cell-apoptosis-and-drug-screening-in-living-cells
#3
Xiaolong Zhang, Naishun Liao, Geng Chen, Aixian Zheng, Yongyi Zeng, Xiaolong Liu, Jingfeng Liu
Herein, a novel dual-responsive two-color fluorescent nanoprobe has been designed for the fluorescence activation imaging of cell apoptosis in living cells. The nanoprobe consists of a gold nanoparticle core functionalized with a dense layer of DNA aptamers and peptides, which shows high affinity and specific response to cytochrome c (Cyt c) and caspase-3, respectively. The formation of the aptamer-Cyt c complex and the cleavage of the specific peptide by caspase-3 can liberate the dye labelled aptamers and peptides from the surface of gold nanoparticles, and then recover their fluorescence...
July 21, 2017: Nanoscale
https://www.readbyqxmd.com/read/28730439/design-and-preparation-of-aptamer-sirna-chimeras-asics-for-targeted-cancer-therapy
#4
Sven Kruspe, Paloma H Giangrande
Conjugation of cell-internalizing DNA or RNA aptamers to tumor-suppressing siRNAs represents a novel promising approach for cancer therapy. Here we describe how to employ RNA aptamers that bind to cell surface receptors as carriers for cell-targeted siRNA (or miRNA) delivery. This protocol was optimized to improve the efficiency of the aptamer-siRNA/miRNA conjugates and facilitate its implementation in most molecular biology labs. The single working steps include (1) outlining the optimal sequences of the RNA strands bearing the aptamer and siRNA sequence, for which further (2) a dsDNA template is synthesized and then (3) transcribed into an RNA that will be (4) folded and annealed to a chemically synthesized siRNA complementary strand...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28730438/x-aptamer-selection-and-validation
#5
Ganesh L Lokesh, Hongyu Wang, Curtis H Lam, Varatharasa Thiviyanathan, Nancy Ward, David G Gorenstein, David E Volk
Aptamers and second generation analogs, such as X-Aptamers (XAs), SOMAmers, locked nucleic acids (LNAs), and others are increasingly being used for molecular pathway targeting, biomarker discovery, or disease diagnosis by interacting with protein targets on the surface of cells or in solution. Such targeting is being used for imaging, diagnostic evaluation, interference of protein function, or delivery of therapeutic agents. Selection of aptamers using the original SELEX method is cumbersome and time-consuming, often requiring 10-15 rounds of selection, and provides aptamers with a limited number of functional groups, namely four bases of DNA or RNA, although newer SELEX methods have increased this diversity...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28730434/cotranscriptional-production-of-chemically-modified-rna-nanoparticles
#6
Maria L Kireeva, Kirill A Afonin, Bruce A Shapiro, Mikhail Kashlev
RNA nanoparticles consisting of multiple RNA strands of different sequences forming various three-dimensional structures emerge as promising carriers of siRNAs, RNA aptamers, and ribozymes. In vitro transcription of a mixture of dsDNA templates encoding all the subunits of the RNA nanoparticle may result in cotranscriptional self-assembly of the nanoparticle. Based on our experience with production of RNA nanorings, RNA nanocubes, and RNA three-way junctions, we propose a strategy for optimization of the cotranscriptional production of chemically modified ribonuclease-resistant RNA nanoparticles...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28730311/aptamer-based-fluorescence-quenching-lateral-flow-strip-for-rapid-detection-of-mercury-ii-ion-in-water-samples
#7
Ze Wu, Haicong Shen, Junhui Hu, Qiangqiang Fu, Cuize Yao, Shiting Yu, Wei Xiao, Yong Tang
Divalent mercury ion (Hg(2+)) is one of the most common and stable forms of mercury pollution. In this study, a skillfully designed lateral flow strip (LFS) was developed for sensitive detection of Hg(2+) in river water samples. Aptamer, a specific oligonucleotide probe, was used to selectively identify and target Hg(2+) instead of antibody in traditional immunechromatographic strips; and the fluorescence-quenching system was used to generate positive and low background florescence signals in the competitive-likely LFS...
July 20, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28729901/aptamer-functionalized-neural-recording-electrodes-for-the-direct-measurement-of-cocaine-in-vivo
#8
I Mitch Taylor, Zhanhong Du, Emma T Bigelow, James R Eles, Anthony R Horner, Kasey A Catt, Stephen G Weber, Brian G Jamieson, X Tracy Cui
Cocaine is a highly addictive psychostimulant that acts through competitive inhibition of the dopamine transporter. In order to fully understand the region specific neuropathology of cocaine abuse and addiction, it is unequivocally necessary to develop cocaine sensing technology capable of directly measuring real-time cocaine transient events local to different brain regions throughout the pharmacokinetic time course of exposure. We have developed an electrochemical aptamer-based in vivo cocaine sensor on a silicon based neural recording probe platform capable of directly measuring cocaine from discrete brain locations using square wave voltammetry (SWV)...
April 7, 2017: Journal of Materials Chemistry. B, Materials for Biology and Medicine
https://www.readbyqxmd.com/read/28728963/structural-principles-of-fluorescent-rna-aptamers
#9
REVIEW
Robert J Trachman, Lynda Truong, Adrian R Ferré-D'Amaré
Several aptamer RNAs have been selected in vitro that bind to otherwise weakly fluorescent small molecules and enhance their fluorescence several thousand-fold. By genetically tagging cellular RNAs of interest with these aptamers and soaking cells in their cell-permeable cognate small-molecule fluorophores, it is possible to use them to study RNA localization and trafficking. These aptamers have also been fused to metabolite-binding RNAs to generate fluorescent biosensors. The 3D structures of three unrelated fluorogenic RNAs have been determined, and reveal a shared reliance on base quadruples (tetrads) to constrain the photo-excited chromophore...
July 17, 2017: Trends in Pharmacological Sciences
https://www.readbyqxmd.com/read/28728900/ultra-sensitive-aptasensor-based-on-a-gqd-nanocomposite-for-detection-of-hepatitis-c-virus-core-antigen
#10
Kazhal Ghanbari, Mahmoud Roushani, Azadeh Azadbakht
In the present study, by using the aptamer proximity binding assay strategy, a novel electrochemical aptasensor is described for ultrasensitive detection of hepatitis C virus (HCV) core antigen. The immobilization surface is prepared by the modification of a glassy carbon electrode (GCE) with a graphene quantum dots (GQD). GQD were introduced as a novel and suitable substrate for aptamers through π-π stacking interactions, the richness of hydrophilic edges as well as hydrophobic plane in GQD which enhances the aptamer absorption on the electrode surface...
July 17, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28728009/bridged-rebar-graphene-functionalized-aptasensor-for-pathogenic-e-coli-o78-k80-h11-detection
#11
Harmanjit Kaur, Munish Shorie, Manju Sharma, Ashok K Ganguli, Priyanka Sabherwal
We report a novel fabrication method of functionalised Bridged Rebar Graphene (BRG) onto newly designed nanostructured aptasensor for label free impedimetric sensing of pathogenic bacteria E. coli O78:K80:H11. The chemical facilitated unscrolling of MWCNT and subsequent bridging with terephthalaldehyde (TPA) to form 3D-hierarchical BRG nanoconstruct exhibited synergistic effect by combining enhanced electrical properties and facile chemical functionality for stable bio-interface. The bacteria-DNA interactions were captured on BRG nanostructured electrode by using specific anti-E...
July 5, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28727998/enrichment-of-endogenous-fractalkine-and-anti-inflammatory-cells-via-aptamer-functionalized-hydrogels
#12
Syed Faaiz Enam, Jack R Krieger, Tarun Saxena, Brian E Watts, Claire E Olingy, Edward A Botchwey, Ravi V Bellamkonda
Early recruitment of non-classical monocytes and their macrophage derivatives is associated with augmented tissue repair and improved integration of biomaterial constructs. A promising therapeutic approach to recruit these subpopulations is by elevating local concentrations of chemoattractants such as fractalkine (FKN, CX3CL1). However, delivering recombinant or purified proteins is not ideal due to their short half-lives, suboptimal efficacy, immunogenic potential, batch variabilities, and cost. Here we report an approach to enrich endogenous FKN, obviating the need for delivery of exogenous proteins...
July 10, 2017: Biomaterials
https://www.readbyqxmd.com/read/28724889/aptamer-mediated-survivin-rnai-enables-5-fluorouracil-to-eliminate-colorectal-cancer-stem-cells
#13
Hadi AlShamaileh, Tao Wang, Dongxi Xiang, Wang Yin, Phuong Ha-Lien Tran, Roberto A Barrero, Pei-Zhuo Zhang, Yong Li, Lingxue Kong, Ke Liu, Shu-Feng Zhou, Yingchun Hou, Sarah Shigdar, Wei Duan
The development of chemoresistance and inability in elimination of cancer stem cells are among the key limitations of cancer chemotherapy. Novel molecular therapeutic strategies able to overcome such limitations are urgently needed for future effective management of cancer. In this report, we show that EpCAM-aptamer-guided survivin RNAi effectively downregulated survivin both in colorectal cancer cells in vitro and in a mouse xenograft model for colorectal cancer. When combined with the conventional chemotherapeutic agents, the aptamer-guided survivin RNAi was able to enhance the sensitivity towards 5-FU or oxaliplatin in colorectal cancer stem cells, increase apoptosis, inhibit tumour growth and improve the overall survival of mice bearing xenograft colorectal cancer...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28723181/mixed-self-assembled-aptamer-and-newly-designed-zwitterionic-peptide-as-antifouling-biosensing-interface-for-electrochemical-detection-of-alpha-fetoprotein
#14
Min Cui, Yu Wang, Mingxia Jiao, Silambarasan Jayachandran, Yumin Wu, Xiaojian Fan, Xiliang Luo
A sensitive and low-fouling aptasensor for alpha-fetoprotein (AFP) was developed based on mixed self-assembled aptamers and newly designed zwitterionic peptides, where densely immobilized peptides formed an antifouling layer to resist nonspecific protein adsorption, and sparsely attached aptamers acted as the recognizing layer to achieve target binding. The obtained biosensing interface responded to the target AFP with a strikingly selective and sensitive manner, exhibited excellent protein-resistant performance even in complex human serum solution, and showed promising feasibility for the quantitative analysis of AFP in real human serum samples...
April 28, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723179/multifunctional-nanofibers-for-specific-purification-and-release-of-ctcs
#15
Zhili Wang, Na Sun, Min Liu, Yi Cao, Kewei Wang, Jine Wang, Renjun Pei
Recovering pure and viable circulating tumor cells (CTCs) from blood has been a challenging task for molecular characterization and functional analysis, which has attracted wide attention these days. Herein, we fabricate a thermoresponsive chitosan nanofiber substrate to effectively capture, purify, and release the target cancer cells, assisted by PNIPAAm brushes and DNA hybridization. The PNIPAAm brushes are designed to enable WBCs to detach from aptamer-PNIPAAm-chitosan-nanofiber (aptamer-P-CNFs) surfaces during the conformational transition...
April 28, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723173/laser-scribed-graphene-electrodes-for-aptamer-based-biosensing
#16
Christoph Fenzl, Pranati Nayak, Thomas Hirsch, Otto S Wolfbeis, Husam N Alshareef, Antje J Baeumner
Graphene as a transducer material has produced some of the best-performing sensing approaches to date opening the door toward integrated miniaturized all-carbon point-of-care devices. Addressing this opportunity, laser-scribed graphene (LSG) electrodes are demonstrated here as highly sensitive and reliable biosensor transducers in blood serum analysis. These flexible electrodes with large electrochemical surface areas were fabricated using a direct-write laser process on polyimide foils. A universal immobilization approach is established by anchoring 1-pyrenebutyric acid to the graphene and subsequently covalently attaching an aptamer against the coagulation factor thrombin as an exemplary bioreceptor to the carboxyl groups...
May 26, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723140/rapid-and-label-free-detection-of-interferon-gamma-via-an-electrochemical-aptasensor-comprising-a-ternary-surface-monolayer-on-a-gold-interdigitated-electrode-array
#17
Shaowei Ding, Curtis Mosher, Xian Y Lee, Suprem R Das, Allison A Cargill, Xiaohui Tang, Bolin Chen, Eric S McLamore, Carmen Gomes, Jesse M Hostetter, Jonathan C Claussen
A label-free electrochemical impedance spectroscopy (EIS) aptasensor for rapid detection (<35 min) of interferon-gamma (IFN-γ) was fabricated by immobilizing a RNA aptamer capture probe (ACP), selective to IFN-γ, on a gold interdigitated electrode array (Au IDE). The ACP was modified with a thiol group at the 5' terminal end and subsequently co-immobilized with 1,6-hexanedithiol (HDT) and 6-mercapto-1-hexanolphosphate (MCH) to the gold surface through thiol-gold interactions. This ACP/HDT-MCH ternary surface monolayer facilitates efficient hybridization with IFN-γ and displays high resistance to nonspecific adsorption of nontarget proteins [i...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723135/development-of-dual-aptamers-for-constructing-sandwich-type-pancreatic-polypeptide-assay
#18
Shiya Qin, Nandi Chen, Xiaohai Yang, Qing Wang, Kemin Wang, Jin Huang, Jianbo Liu, Maogui Zhou
Pancreatic polypeptide (PP) is a specific biomarker of nonfunctional pancreatic neuroendocrine tumors (NF-pNETs). Clinical significance of PP inspires researchers to make great efforts in developing sensitive and specific sensors. However, there is no existing biosensor for detecting PP that combines facility and functionality. Addressing this challenge, a pair of aptamers which could be used to develop a sandwich assay for PP is reported. First, several high affinity aptamers are screened through graphene oxide-based SELEX, and appropriate dual-aptamers which could bind to different epitopes of PP are identified through fluorescence assays...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723133/label-free-nanopore-biosensor-for-rapid-and-highly-sensitive-cocaine-detection-in-complex-biological-fluids
#19
Sana Rauf, Ling Zhang, Asghar Ali, Yang Liu, Jinghong Li
Detection of very low amounts of illicit drugs such as cocaine in clinical fluids like serum continues to be important for many areas in the fight against drug trafficking. Herein, we constructed a label-free nanopore biosensor for rapid and highly sensitive detection of cocaine in human serum and saliva samples based on target-induced strand release strategy. In this bioassay, an aptamer for cocaine was prehybridized with a short complementary DNA. Owing to cocaine specific binding with aptamer, the short DNA strand was displaced from aptamer and translocation of this output DNA through α-hemolysin nanopore generated distinct spike-like current blockages...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28722429/detection-of-k-efflux-from-stimulated-cortical-neurons-by-an-aptamer-modified-silicon-nanowire-field-effect-transistor
#20
Ankur Anand, Chia-Rung Liu, Ai-Chuan Chou, Wan-Hsuan Hsu, Rajesh Kumar Ulaganathan, Yi-Cheng Lin, Chi-An Dai, Fan-Gang Tseng, Chien-Yuan Pan, Yit-Tsong Chen
The concentration gradient of K(+) across the cell membrane of a neuron determines its resting potential and cell excitability. During neurotransmission, the efflux of K(+) from the cell via various channels will not only decrease the intracellular K(+) content but also elevate the extracellular K(+) concentration. However, it is not clear to what extent this change could be. In this study, we developed a multiple-parallel-connected silicon nanowire field-effect transistor (SiNW-FET) modified with K(+)-specific DNA-aptamers (aptamer/SiNW-FET) for the real-time detection of the K(+) efflux from cultured cortical neurons...
January 27, 2017: ACS Sensors
keyword
keyword
41159
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"