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Aptasensors

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https://www.readbyqxmd.com/read/28319905/a-new-amplified-%C3%AF-shape-electrochemical-aptasensor-for-ultrasensitive-detection-of-aflatoxin-b1
#1
Khalil Abnous, Noor Mohammad Danesh, Mona Alibolandi, Mohammad Ramezani, Ahmad Sarreshtehdar Emrani, Reza Zolfaghari, Seyed Mohammad Taghdisi
There is a prompt need for determination of aflatoxin B1 (AFB1) in food products to avoid distribution and consumption of contaminated food products. In this study, an accurate electrochemical sensing strategy was presented for detection of AFB1 based on aptamer (Apt)-complementary strands of aptamer (CSs) complex which forms a π-shape structure on the surface of electrode and exonuclease I (Exo I). The presence of π-shape structure as a double-layer physical barrier allowed detection of AFB1 with high sensitivity...
March 17, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28319903/fe-iii-based-metal-organic-framework-derived-core-shell-nanostructure-sensitive-electrochemical-platform-for-high-trace-determination-of-heavy-metal-ions
#2
Zhihong Zhang, Hongfei Ji, Yingpan Song, Shuai Zhang, Minghua Wang, Changchang Jia, Jia-Yue Tian, Linghao He, Xiaojing Zhang, Chun-Sen Liu
A new core-shell nanostructured composite composed of Fe(III)-based metal-organic framework (Fe-MOF) and mesoporous Fe3O4@C nanocapsules (denoted as Fe-MOF@mFe3O4@mC) was synthesized and developed as a platform for determining trace heavy metal ions in aqueous solution. Herein, the mFe3O4@mC nanocapsules were prepared by calcining the hollow Fe3O4@C that was obtained using the SiO2 nanoparticles as the template, followed by composing the Fe-MOF. The Fe-MOF@mFe3O4@mC nanocomposite demonstrated excellent electrochemical activity, water stability and high specific surface area, consequently resulting in the strong biobinding with heavy-metal-ion-targeted aptamer strands...
March 7, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28299702/optical-and-electrochemical-aptasensors-for-sensitive-detection-of-streptomycin-in-blood-serum-and-milk
#3
Mohammad Ramezani, Khalil Abnous, Seyed Mohammad Taghdisi
Detection and quantitation of antibiotic residues in blood serum and foodstuffs are in great demand. We have developed aptasensors for detection of streptomycin using electrochemical and optical methods. In the first method, an electrochemical aptasensor was developed for sensitive and selective detection of streptomycin, based on combination of exonuclease I (Exo I), complementary strand of aptamer (CS), arch shaped structure of aptamer (Apt)-CS conjugate, and gold electrode. The designed electrochemical aptasensor exhibited high selectivity toward streptomycin with a limit of detection (LOD) as low as 11...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28299701/aptasensors-for-detection-of-avian-influenza-virus-h5n1
#4
Yanbin Li, Ronghui Wang
Aptamers are single-stranded RNA or DNA oligonucleotides which have specific three-dimensional (3D) structures for high affinity and specific recognition to their target. In diagnostic and detection assays, aptamers represent an alternative to antibodies as recognition agents and offer advantages, such as reduced cost, rapid and reproducible synthesis, controllable modification, and improved stability. Aptamers are favorably used in biosensors as sensitive and selective bio-receptors coupled with a variety of transducers such as optical, mass-sensitive, and electrochemical sensors, the so-called aptasensors...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28299681/screen-printed-all-polymer-aptasensor-for-impedance-based-detection-of-influenza-a-virus
#5
Julie Kirkegaard, Noemi Rozlosnik
In this chapter a detailed description of the fabrication and testing of an aptasensor for influenza A virus detection is given. The sensor chip is an all-polymer chip fabricated with screen-printed poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrodes. Chip substrates are made by CO2 laser cutting of Poly(methyl methacrylate) (PMMA) sheets. Influenza A virus specific aptamers are immobilized onto the electrodes by UV cross-linking. Impedance based measurements at a single frequency, measured over time, are used to detect the virus in a buffer solution...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28292735/a-novel-sers-based-magnetic-aptasensor-for-prostate-specific-antigen-assay-with-high-sensitivity
#6
Kang Yang, Yongjun Hu, Ning Dong, Guichi Zhu, Tingfeng Zhu, Ningjing Jiang
The accurate and highly sensitive detection of prostate specific antigen (PSA) is particularly important, especially for obese men and patients. In this report, we present a novel aptamer-based surface-enhanced Raman scattering (SERS) sensor that employs magnetic nanoparticles (MNPs) core-Au nanoparticles (AuNPs) satellite assemblies to detect PSA. The high specific biorecognition between aptamer and PSA caused the dissolution of the core-satellite assemblies, thus the concentration of functionalized AuNPs (signal probes) existing in the supernatant was on the rise with the continual addition of PSA...
March 1, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28287705/aptasensor-with-expanded-nucleotide-using-dna-nanotetrahedra-for-electrochemical-detection-of-cancerous-exosomes
#7
Sai Wang, Liqin Zhang, Shuo Wan, Sena Cansiz, Cheng Cui, Yuan Liu, Ren Cai, Chengyi Hong, I-Ting Teng, Muling Shi, Yuan Wu, Yiyang Dong, Weihong Tan
Exosomes are extracellular vesicles (50-100 nm) circulating in biofluids as intercellular signal transmitters. Although the potential of cancerous exosomes as tumor biomarkers is promising, sensitive and rapid detection of exosomes remains challenging. Herein, we combined the strengths of advanced aptamer technology, DNA-based nanostructure, and portable electrochemical devices to develop a nanotetrahedron (NTH)-assisted aptasensor for direct capture and detection of hepatocellular exosomes. The oriented immobilization of aptamers significantly improved the accessibility of an artificial nucleobase-containing aptamer to suspended exosomes, and the NTH-assisted aptasensor could detect exosomes with 100-fold higher sensitivity when compared to the single-stranded aptamer-functionalized aptasensor...
March 20, 2017: ACS Nano
https://www.readbyqxmd.com/read/28285035/development-of-aflatoxin-b1-aptasensor-based-on-wide-range-fluorescence-detection-using-graphene-oxide-quencher
#8
Minyoung Joo, Seung Hoon Baek, Seon Ah Cheon, Hyang Sook Chun, Sung-Wook Choi, Tae Jung Park
Aflatoxin B1 (AFB1) is a carcinogenic substance produced by fungi of genus Aspergillus, especially Aspergillus flavus. Few nanograms of AFB1 that permeated through the skin is sufficient to cause liver cancer and stunted growth. In this study, a rapid aptamer-based assay for AFB1 was developed using the fluorescence quenching property of graphene oxide (GO) and a fluorescein amidite (FAM)-modified aptamer specific to AFB1. The aptamer, modified with the fluorescence dye FAM on its 5'-end, was used as a probe...
March 6, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28283448/a-colorimetric-aptasensor-for-sulfadimethoxine-detection-based-on-peroxidase-like-activity-of-graphene-nickel-palladium-hybrids
#9
Aicheng Wang, Huimin Zhao, Xiaochi Chen, Bing Tan, Yaobin Zhang, Xie Quan
A sensitive, rapid and label-free colorimetric aptasensor for sulfadimethoxine (SDM) detection was developed based on the tunable peroxidase-like activity of graphene/nickel@palladium nanoparticle (Gr/Ni@Pd) hybrids. The addition of the SDM aptamer could inhibit the peroxidase-like catalytic activity of the hybrids. However, the target SDM and aptamer could be triggered tightly and recover the catalytic activity of the Gr/Ni@Pd hybrids. Due to the peroxidase-like catalytic activity, Gr/Ni@Pd could catalyze the decomposition of H2O2 with releasing hydroxyl radicals which further oxidized reagent 3, 3', 5, 5'-Tetramethylbenzidine (TMB) to oxTMB accompanied with a colorless-to-blue color change...
March 7, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28276559/a-colorimetric-nanosensor-based-on-a-selective-target-responsive-aptamer-kissing-complex
#10
E Goux, E Dausse, V Guieu, L Azéma, G Durand, M Henry, L Choisnard, J-J Toulmé, C Ravelet, E Peyrin
Herein, we report a novel approach for the design of a colorimetric aptasensor based on functionalized gold nanoparticle probes. This approach relies on the conjugation of nanoparticles by two functional DNA and RNA hairpins that engage specific kissing (loop-loop) interactions in response to the addition of a small analyte ligand, leading to particle aggregation and then red-to-purple colour change of the colloidal solution.
March 9, 2017: Nanoscale
https://www.readbyqxmd.com/read/28264568/selection-and-characterization-of-dna-aptamers-for-electrochemical-biosensing-of-carbendazim
#11
Shimaa Eissa, Mohammed Zourob
This article reports a novel aptamer-based impedimetric detection of carbendazim, a commonly used benzimidazole fungicide in agriculture. High affinity and specificity DNA aptamers against carbendazim were successfully selected using systematic evolution of ligand by exponential enrichment (SELEX). The dissociation constants (Kds) of the selected DNA aptamers after 10 in vitro selection cycles were characterized using fluorescence-based assays showing values in the nanomolar range. The aptamer which showed the highest degree of affinity and conformation change was used to fabricate an electrochemical aptasensor via self-assembly of thiol-modified aptamer on gold electrodes...
March 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28249387/-dna-origami-traffic-lights-with-a-split-aptamer-sensor-for-a-bicolor-fluorescence-readout
#12
Heidi-Kristin Walter, Jens Bauer, Jeannine Steinmeyer, Akinori Kuzuya, Christof M Niemeyer, Hans-Achim Wagenknecht
A split aptamer for adenosine triphosphate (ATP) was embedded as a recognition unit into two levers of a nanomechanical DNA origami construct by extension and modification of selected staple strands. An additional optical module in the stem of the split aptamer comprised two different cyanine-styryl dyes that underwent an energy transfer from green (donor) to red (acceptor) emission if two ATP molecules were bound as target molecule to the recognition module and thereby brought the dyes in close proximity. As a result, the ATP as a target triggered the DNA origami shape transition and yielded a fluorescence color change from green to red as readout...
March 8, 2017: Nano Letters
https://www.readbyqxmd.com/read/28237255/high-affinity-truncated-dna-aptamers-for-the-development-of-fluorescence-based-progesterone-biosensors
#13
Hani A Alhadrami, Raja Chinnappan, Shimaa Eissa, Anas Abdel Rahamn, Mohammed Zourob
Aptamers have shown a number of potential applications in sensing and therapeutic due to the high affinity and specificity towards their target molecules. Not all the nucleotides in the full length aptamers are involved in the binding with their targets. The non-binding domain of the aptamer may affect the binding affinity of the aptamer-target complex. Mapping the aptamer binding region could increase the affinity and the specificity. In this paper, we designed aptamer-based fluorescence sensors from a truncated progesterone (P4) aptamer...
February 24, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28231553/a-reusable-aptasensor-of-thrombin-based-on-dna-machine-employing-resonance-light-scattering-technique
#14
Yining Hou, Jifeng Liu, Min Hong, Xia Li, Yanhua Ma, Qiaoli Yue, Chen-Zhong Li
The design of molecular nanodevices attracted great interest in these years. Herein, a reusable, sensitive and specific aptasensor was constructed based on an extension-contraction movement of DNA interconversion for the application of human thrombin detection. The present biosensor was based on resonance light scattering (RLS) using magnetic nanoparticles (MNPs) as the RLS probe. MNPs coated with streptavidin can combine with biotin labeled thrombin aptamers. The combined nanoparticles composite is monodispersed in aqueous medium...
June 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28231552/progress-and-challenges-in-electrochemiluminescent-aptasensors
#15
REVIEW
Kateryna Muzyka, Muhammad Saqib, Zhongyuan Liu, Wei Zhang, Guobao Xu
The importance of developing new diagnostic and detection technologies for the growing number of sensing challenges is rising each year. Here, we present a comprehensive and concise review on electrochemiluminescent (ECL) aptasensors by putting special emphasis on its characteristic features, advances, challenges, and applications of ECL based aptasensors. ECL is an ideal tool for constructing such sensors because of its inherent characteristics and can be easily integrated into aptamer based sensing platforms...
June 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28225598/novel-aptasensor-platform-based-on-ratiometric-surface-enhanced-raman-spectroscopy
#16
Yan Wu, Fubing Xiao, Zhaoyang Wu, Ruqin Yu
A novel aptasensor platform has been developed for quantitative detection of adenosine triphosphate (ATP) based on a ratiometric surface-enhanced Raman scattering (SERS) strategy. The thiolated 3'-Rox-labeled complementary DNA (cDNA) is first immobilized on the gold nanoparticle (AuNP) surface and then hybridizes with the 3'-Cy5-labeled ATP-binding aptamer probe (Cy5-aptamer) to form a rigid double-stranded DNA (dsDNA), in which the Cy5 and Rox Raman labels are used to produce the ratiometric Raman signals...
February 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28219246/dna-generated-electric-current-biosensor
#17
Lanshuang Hu, Shengqiang Hu, Linyan Guo, Congcong Shen, Minghui Yang, Avraham Rasooly
In addition to its primary function as a genetic material, deoxyribonucleic acid (DNA) is also a potential biologic energy source for molecular electronics. For the first time, we demonstrate that DNA can generate a redox electric current. As an example of this new functionality, DNA generated redox current was used for electrochemical detection of human epidermal growth factor receptor 2 (HER2), a clinically important breast cancer biomarker. To induce redox current, the phosphate of the single stranded DNA aptamer backbone was reacted with molybdate to form redox molybdophosphate precipitate and generate an electrochemical current of ∼16...
February 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28214746/a-magnetite-pmaa-nanospheres-targeting-sers-aptasensor-for-tetracycline-sensing-using-mercapto-molecules-embedded-core-shell-nanoparticles-for-signal-amplification
#18
Huanhuan Li, Quansheng Chen, Md Mehedi Hassan, Xiaoxing Chen, Qin Ouyang, Zhiming Guo, Jiewen Zhao
Surface-enhanced Raman scattering (SERS) biosensors have promising potential in the field of antibiotics detection because of their ultrahigh detection sensitivity. This paper reports a rapid and sensitive SERS-based magnetic nanospheres-targeting strategy for sensing tetracycline (TTC) using aptamer-conjugated magnetite colloid nanocrystal clusters (MCNCs)-polymethacrylic acid (PMAA) magnetic nanospheres (MNs) as the recognition and the Au/PATP/SiO2 (APS) as the labels. Initially, MNs were fabricated and conjugated with the aptamers through condensation reaction...
June 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28213221/a-novel-fluorescent-aptasensor-for-ultrasensitive-detection-of-microcystin-lr-based-on-single-walled-carbon-nanotubes-and-dapoxyl
#19
Seyed Mohammad Taghdisi, Noor Mohammad Danesh, Mohammad Ramezani, Narjes Ghows, Seyed Ali Mousavi Shaegh, Khalil Abnous
To assure water safety and protect human health, precise and simple analytical approaches are highly desired to determine low concentrations of microcystin-leucine-arginine (MC-LR), a toxin, in both water and serum samples. Herein, a simple, rapid and accurate aptamer-based fluorescent sensor was used for selective recognition of MC-LR, based on single-walled carbon nanotubes (SWNTs) as immobilizers, dapoxyl as a fluorescent dye, DAP-10 as a specific aptamer for dapoxyl and unmodified MC-LR aptamer (Apt) as a sensing ligand...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28208296/ultrasensitive-self-powered-aptasensor-based-on-enzyme-biofuel-cell-and-dna-bioconjugate-a-facile-and-powerful-tool-for-antibiotic-residue-detection
#20
Panpan Gai, Chengcheng Gu, Ting Hou, Feng Li
Herein, we reported a novel ultrasensitive one-compartment enzyme biofuel cells (EBFCs)-based self-powered aptasensing platform for antibiotic residue detection. By taking full advantage of the unique features of both EBFCs-based self-powered sensors and aptamers, the as-proposed aptasensing platform has the merits of simple instrumentation, anti-interference ability, high selectivity, and low cost. In this study, DNA bioconjugate, i.e., SiO2@gold nanoparticles-complementary strand of aptamer (SiO2@AuNPs-csDNA), was elaborately designed and played a key role in blocking the mass transport of glucose to the bioanode...
February 7, 2017: Analytical Chemistry
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