Read by QxMD icon Read


Asma Verdian
In an effort to achieve high sensitive and selective detection of pesticide residues, numerous nanomaterial-based aptasensors are currently being developed for acetamiprid analysis. Recently, aptamers as a potent alternative of antibodies are used in biosensing platforms. There is tremendous interest in utilizing of nanomaterial as basic building blocks and signaling elements in aptasensors. The nanomaterials have the unique optical and electrical properties. The combination of nanomaterial and aptamer technology has opened a new window in pesticide residues monitoring...
January 1, 2018: Talanta
Taofeng Lu, Qin Ma, Wenzhuo Yan, Yuanzhi Wang, Yuanyuan Zhang, Lili Zhao, Hongyan Chen
Muscovy duck parvovirus (MDPV) causes high mortality and morbidity in ducks. This study investigated a novel aptamer-based, label-free aptasensor detection of MDPV. In this study, we developed an ssDNA aptamer using the filtration partition and lambda exonuclease method with an affinity-based monitor and counter-screening process. After 15 rounds of SELEX (systematic evolution of ligands by exponential enrichment), the ssDNA aptamer Apt-10, which specifically bound to MDPV with high affinity (Kd = 467nM) was successfully screened, and the aptamer was also found to be good specific to MDPV...
January 1, 2018: Talanta
Sofia G Meirinho, Luís G Dias, António M Peres, Lígia R Rodrigues
A DNA aptamer with affinity and specificity for human osteopontin (OPN), a potential breast cancer biomarker, was selected using the SELEX process, considering its homology rate and the stability of its secondary structures. This aptamer exhibited a satisfactory affinity towards OPN, showing dissociation constants lower than 2.5 nM. It was further used to develop a simple, label-free electrochemical aptasensor against OPN. The aptasensor showed good sensitivity towards OPN in standard solutions, being the square wave voltammetry (SWV), compared to the cyclic voltammetry, the most sensitive technique with detection and quantification limits of 1...
September 22, 2017: Analytica Chimica Acta
Shijia Wu, Nuo Duan, Yueting Qiu, Jinghong Li, Zhouping Wang
A new colorimetric aptasensor platform was fabricated to detect Salmonella enterica serovar typhimurium based on the peroxidase-like activity of ZnFe2O4-reduced graphene oxide (ZnFe2O4/rGO) nanostructures. The synthesized ZnFe2O4/rGO can catalytically oxidize 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 and generate a typical blue product, which was detected by micro-reader at 652nm. Therefore, ZnFe2O4/rGO was conjugated with aptamer to act as the signal probe. Biotin modified aptamer was immobilized onto the micro-plate to act as the capture probe...
September 6, 2017: International Journal of Food Microbiology
Naghmeh Sattarahmady, Amid Rahi, Hossein Heli
A green electrodeposition method was firstly employed for the synthesis of round hairbrush-like gold nanostructure in the presence of cadaverine as a size and shape directing additive. The nanostructure which comprised of arrays of nanospindles was then applied as a transducer to fabricate a signal-on built in-marker electrochemical aptasensor for the detection of human prostate-specific antigen (PSA). The aptasensor detected PSA with a linear concentration range of 0.125 to 128 ng mL(-1) and a limit of detection of 50 pg mL(-1)...
September 11, 2017: Scientific Reports
Huayi Shi, Na Chen, Yuanyuan Su, Houyu Wang, Yao He
Rapid, sensitive and accurate detection of adenosine triphosphate (ATP), the primary energy molecule, is critical for the elucidation of its unique roles in cell signaling and many cellular reactions. Up to date, major challenge is still remaining for fabricating surface-enhanced Raman scattering (SERS) aptamer sensors (aptasensors), suitable for accurate and reliable quantification of ATP. Herein, we develop the ratiometric silicon SERS aptasensor for ATP detection, which is made of uniform silver nanoparticles (Ag NPs)-modified silicon wafer (Ag NPs@Si), followed by the functionalization with double-stranded DNA (dsDNA I)...
September 8, 2017: Analytical Chemistry
Jegatha Nambi Krishnan, Sang-Hwi Park, Sang Kyung Kim
A new single-step aptamer-based surface-enhanced fluorescent optical sensor is built, by combining an aptamer-target interaction for target recognition and a fluorophore interaction for signal enhancement. The developed aptasensor is simple, sensitive, specific and stable for the detection of thrombin. A new nanometallic Au structure in the range of 100 nm was constructed through effective electroless plating method on a Cu thin film. Cu⁺ ions act as sacrificial seeds for the reduction of Au(2+/3+) ions to form Au nanolawns...
September 7, 2017: Sensors
Mingxiu Yang, Guokun Liu, Hassan Md Mehedi, Qin Ouyang, Quansheng Chen
A novel universal Surface-enhanced Raman Spectroscopy (SERS) based aptasensor platform for the trace detection of Aflatoxin B1 (AFB1), a common food contaminating mycotoxin, has been constructed, with the aid of the specific interaction between AFB1 and aptamers. The amino-terminal aptamer conjugated magnetic-bead (CS-Fe3O4) and the gold nanotriangles (GNTs)-DTNB@Ag-DTNB nanotriangles (GDADNTs) were used as the capturer and the reporter of AFB1, respectively. Under the optimized assay condition, the platform shows a distinguished sensitivity with the LOD as low as 0...
September 15, 2017: Analytica Chimica Acta
Mahmoud Amouzadeh Tabrizi, Mojtaba Shamsipur, Reza Saber, Saeed Sarkar
In this research, we demonstrated a flow injection amperometric sandwich-type aptasensor for the determination of human leukemic lymphoblasts (CCRF-CEM) based on poly(3,4-ethylenedioxythiophene) decorated with gold nanoparticles (PEDOT-Aunano) as a nano platform to immobilize thiolated sgc8c aptamer and multiwall carbon nanotubes decorated with palladium nanoparticles/3,4,9,10-perylene tetracarboxylic acid (MWCNTs-Pdnano/PTCA) to fabricate catalytic labeled aptamer. In the proposed sensing strategy, the CCRF-CEM cancer cells were sandwiched between immobilized sgc8c aptamer on PEDOT-Aunano modified surface electrode and catalytic labeled sgc8c aptamer (MWCNTs-Pdnano/PTCA/aptamer)...
September 8, 2017: Analytica Chimica Acta
Congcong Shen, Ke Zeng, Junjun Luo, Xiaoqing Li, Minghui Yang, Avraham Rasooly
We have developed a new DNA self-assembly amplification technology that generates electric current to power electrochemical biosensing. The new technology was used for detection of human epidermal growth factor receptor 2 (HER2). In our technology, an aptamer was utilized both as a ligand for recognition and as a signal generating reporter. The aptasensor is based on a sandwich format: a DNA primer on a HER2 aptamer initiates auxiliary DNA self-assembly on the electrode to form a long one-dimensional DNA. The resulting DNA is then reacted with molybdate to generate electrochemical current...
September 1, 2017: Analytical Chemistry
Xu Wang, Guanhong Xu, Fangdi Wei, Yunsu Ma, Yujie Ma, Yueyue Song, Yao Cen, Qin Hu
In this article, a novel aptasensor was fabricated by modifying carbon dots (CDs) with adenosine aptamer (CDs-aptamer) for sensitive, selective and quantitative detection of adenosine (AD). When nano-graphite (NG) as an energy acceptor was added into the CDs-aptamer (energy donor) solution, the fluorescence of CDs-aptamer was quenched due to fluorescence resonance energy transfer (FRET). When AD was present in the solution of CDs-aptamer/NG, the process of FRET was inhibited because of the specific combination between AD and AD aptamer...
July 10, 2017: Journal of Colloid and Interface Science
Shreya Ghosh, Debopam Datta, Mehar Cheema, Mitra Dutta, Michael A Stroscio
Glycated Albumin (GA) has been reported as an important biomarker for diabetes mellitus. This study investigates an optical sensor comprised of deoxyribonucleic acid (DNA) aptamer, semiconductor quantum dot and gold (Au) nanoparticle for the detection of GA. The system functions as a 'turn on' sensor because an increase in photoluminescence intensity is observed upon the addition of glycated albumin to the sensor. This is possibly because of the structure of the DNA aptamer, which folds to form a large hairpin loop before the addition of the analyte and is assumed to open up after the addition of target to the sensor in order to bind to GA...
August 30, 2017: Nanotechnology
Yanyan Li, Manru Zhao, Haiyan Wang
We report a label-free peptide aptamer based biosensor for highly sensitive detection of TNT which was designed with a ternary assembly layer consisting of anti-TNT peptide aptamer (peptamer), dithiothreitol (DTT), and 6-mercaptohexanol (MCH), forming Au/peptamer-DTT/MCH. A linear relationship between the change in electron transfer resistance and the logarithm of the TNT concentration from 0.44 to 18.92 pM, with a detection limit of 0.15 pM, was obtained. In comparison, the detection limit of the aptasensor with a common binary assembly layer (Au/peptamer/MCH) was 0...
August 29, 2017: Analytical and Bioanalytical Chemistry
Ayemeh Bagheri Hashkavayi, Jahan Bakhsh Raoof, Reza Ojani
In this work, a highly sensitive, low-cost, and label-free aptasensor based on signal-on mechanisms of response was developed by immobilizing the aptamer on gold nanoparticles (AuNPs)/amine-functionalized silica nanoparticle (FSN)/screen-printed electrode (SPE) surface for highly selective electrochemical detection of tryptophan (Trp). The hemin (Hem), which interacted with the guanine bases of the aptamer, worked as a redox indicator to generate a readable electrochemical signal. The changes in the charge transfer resistance have been monitored using the voltammetry and electrochemical impedance spectroscopic (EIS) techniques...
August 29, 2017: Analytical and Bioanalytical Chemistry
Zewei Luo, Yimin Wang, Xiaoyong Lu, Junman Chen, Fujing Wei, Zhijun Huang, Chen Zhou, Yixiang Duan
Antibiotic abuse has been bringing serious pollution in water, which is closely related to human health. It is desirable to develop a new strategy for antibiotic detection. To address this problem, a sensitive fluorescent aptasensor for antibiotic detection was developed by utilizing gold nanoparticles modified magnetic bead composites (AuNPs/MBs) and nicking enzyme. AuNPs/MBs were synthesized with the help of polyethylenimine (PEI). The prepared AuNPs/MBs acted as dual-functional scaffolds that owned excellent magnetic separation capacity and strong covalent bio-conjugation...
September 1, 2017: Analytica Chimica Acta
Seyed Mohammad Taghdisi, Noor Mohammad Danesh, Mohammad Ramezani, Rezvan Yazdian-Robati, Khalil Abnous
It is great significance to identify interferon-gamma (IFN-γ), as a biological marker for diagnosis of latent tuberculosis, in serum samples. In this paper, a novel fluorescent aptasensor was fabricated and applied for sensitive and specific detection of IFN-γ. This biosensor was based on hairpin structure of oligonucleotide, single-stranded DNA-binding protein (SSB), copper nanoparticles (CuNPs) and silica nanoparticles coated with streptavidin (SNPs-Streptavidin). The presences of double-stranded DNA (dsDNA) region and poly thymine (T) in the hairpin structure of the oligonucleotide, SSB and SNPs-streptavidin caused IFN-γ determination with high selectivity and sensitivity...
September 1, 2017: Analytica Chimica Acta
Yan Wu, Tingting Jiang, Zhaoyang Wu, Ruqin Yu
It is important to precisely monitor mercury (II) ions (Hg(2+)) for environment protection and human health monitoring. Although many strategies have been developed in the past decades, there still remains a challenge for developing an ultrasensitive, simple and reliable approach to detect Hg(2+). Herein, we report a ratiometric surface-enhanced Raman scattering (SERS) aptasensor by employing aptamer-modified Au@Ag core-shell nanoparticles (Au@Ag NPs) as highly functional sensing probes, allowing for ultrasensitive detection of Hg(2+)...
August 19, 2017: Biosensors & Bioelectronics
Joshua N Yoho, Brian Geier, Claude C Grigsby, Joshua A Hagen, Jorge L Chávez, Nancy Kelley-Loughnane
In this work, we developed an assay to determine if an arbitrary white powder is a controlled substance, given the plasmonic response of aptamer-gold nanoparticle conjugates (Apt-AuNPs). Toward this end, we designed Apt-AuNPs with specific a response to common controlled substances without cross reactivity to chemicals typically used as fillers in street formulations. Plasmonic sensor variation was shown to produce unique data fingerprints for each chemical analyzed, supporting the application of multivariate statistical techniques to annotate unknown samples by chemical similarity...
August 23, 2017: Sensors
Guixiang Wang, Qingjun Xu, Lei Liu, Xiaoli Su, Jiehua Lin, Guiyun Xu, Xiliang Luo
Detection of disease biomarkers within complex biological media is a substantial outstanding challenge because of severe biofouling and nonspecific adsorptions. Herein, a reliable strategy for sensitive and low-fouling detection of a biomarker, adenosine triphosphate (ATP) in biological samples was developed through the formation of a mixed self-assembled sensing interface, which was constructed by simultaneously self-assembling polyethylene glycol (PEG) and ATP aptamer onto the self-polymerized polydopamine-modified electrode surface...
September 13, 2017: ACS Applied Materials & Interfaces
Zhen Wang, Hua Yu, Jing Han, Gang Xie, Sanping Chen
Here we report a surprising discovery that Co/Fe-MOFs possess intrinsic electrocatalytic activities for thionine. The catalytic abilities of MOFs depend strongly on their μ3-O linked trigonal prism structures. Using NH2-Co-MOF as an example, the high-performance of electrocatalysis towards thionine for ultrasensitive electrochemical detection of ochratoxin A is first established.
August 31, 2017: Chemical Communications: Chem Comm
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"