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Ultrasensitive immunoassay

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https://www.readbyqxmd.com/read/28734353/streptavidin-biotin-peroxidase-nanocomplex-amplified-microfluidics-immunoassays-for-simultaneous-detection-of-inflammatory-biomarkers
#1
Jing Wu, Yiping Chen, Mingzhu Yang, Yu Wang, Cheng Zhang, Mo Yang, Jiashu Sun, Mengxia Xie, Xingyu Jiang
Simultaneous, sensitive and quantitative detection of biomarkers in infectious disease is crucial for guiding antimicrobial treatment and predicting prognosis. This work reported an ultrasensitive and quantitative microfluidic immunoassay combined with the streptavidin-biotin-peroxidase (SA-B-HRP) nanocomplex-signal amplification system (MIS) to detect two inflammatory biomarkers, procalcitonin (PCT, for discriminating bacterial infections from nonbacterial infections) and interleukin-6 (IL-6, for monitoring the kinetics of infectious disease) simultaneously...
August 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28724286/deep-dive-targeted-quantification-for-ultrasensitive-analysis-of-proteins-in-non-depleted-human-blood-plasma-serum-and-tissues
#2
Song Nie, Tujin Shi, Thomas L Fillmore, Athena A Schepmoes, Heather Brewer, Yuqian Gao, Ehwang Song, Hui Wang, Karin D Rodland, Wei-Jun Qian, Richard D Smith, Tao Liu
Mass spectrometry-based targeted proteomics (e.g., selected reaction monitoring, SRM) is emerging as an attractive alternative to immunoassays for protein quantification. Recently we have made significant progress in SRM sensitivity for enabling quantification of low ng/mL to sub-ng/mL level proteins in non-depleted human blood plasma/serum without affinity enrichment. However, precise quantification of extremely low abundance proteins (e.g., ≤100 pg/mL in blood plasma/serum) using targeted proteomics approaches still remains challenging, especially for these samples without available antibodies for enrichment...
July 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28723149/cyclewise-operation-of-printed-mos2-transistor-biosensors-for-rapid-biomolecule-quantification-at-femtomolar-levels
#3
Byunghoon Ryu, Hongsuk Nam, Bo-Ram Oh, Yujing Song, Pengyu Chen, Younggeun Park, Wenjie Wan, Katsuo Kurabayashi, Xiaogan Liang
Field-effect transistors made from MoS2 and other emerging layered semiconductors have been demonstrated to be able to serve as ultrasensitive biosensors. However, such nanoelectronic sensors still suffer seriously from a series of challenges associated with the poor compatibility between electronic structures and liquid analytes. These challenges hinder the practical biosensing applications that demand rapid, low-noise, highly specific biomolecule quantification at femtomolar levels. To address such challenges, we study a cyclewise process for operating MoS2 transistor biosensors, in which a series of reagent fluids are delivered to the sensor in a time-sequenced manner and periodically set the sensor into four assay-cycle stages, including incubation, flushing, drying, and electrical measurement...
February 24, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28662470/multiple-functional-strategies-for-amplifying-sensitivity-of-amperometric-immunoassay-for-tumor-markers-a-review
#4
REVIEW
Zhongxue Tang, Zhanfang Ma
Multiple functional strategies have shown great potential in ultrasensitive amperometric immunoassays for tumor markers, which promote conductivity and signal multiple amplification. The sensitivity of amperometric immunoassays is significantly affected by the conductivity and specific area of the sensing interface as well as the electrochemical activity of redox species. Thus, these strategies are generally based on integrating various materials together and endowing immunosensing systems with many advantages, such as large specific area, high electrochemical activity, good conductivity, biocompatibility, and catalytic performance...
June 21, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28650005/sub-picomolar-label-free-detection-of-thrombin-using-electrochemical-impedance-spectroscopy-of-aptamer-functionalized-mos2
#5
Kai-Chun Lin, Badrinath Jagannath, Sriram Muthukumar, Shalini Prasad
An ultrasensitive aptasensor for the label free non-faradaic detection of thrombin has been demonstrated on molybdenum disulphide (MoS2) nanosheets. These nanosheets were physiochemically immobilized onto a silicon micro-electrode platform. Thrombin detection was achieved through the charge modulation of the electrical double layer due to the specific and dose dependent binding of thrombin to the surface of thiol terminated ssDNA aptamer functionalized MoS2 nanosheets. Electrical double layer charge modulation associated with thrombin binding was characterized using electrochemical impedance spectroscopy...
July 24, 2017: Analyst
https://www.readbyqxmd.com/read/28627218/performance-evaluation-of-three-platforms-with-ultrasensitive-ligand-binding-assay-potential
#6
Kyra Juliana Cowan, Albert Geiger, Hans Hornauer, Robyn Rourick, Patricia Yanira Siguenza
AIM: We evaluated three immunoassay-based technologies and their biomarker kits, by determining precision, parallelism and detectability of analytes of interest. MATERIALS & METHODS: We compared ultrasensitive assays for three biomarkers: interleukins IL-6, IL-13 and IL-17A using kits obtained from Roche (IMPACT platform - proprietary platform), Singulex (Erenna(®)) and Quanterix (Simoa(™)). We defined the true LLOD as the LLOQs, and provided disease-specific parallelism results and detectability levels for endogenous analyte, which were good across platforms, though they varied from analyte to analyte...
June 2017: Bioanalysis
https://www.readbyqxmd.com/read/28550286/ultrasensitive-multiplexed-immunoassay-of-autophagic-biomarkers-based-on-au-rgo-and-au-nanocages-amplifying-electrochemcial-signal
#7
Guannan Wang, Yankun Li, Jinlei Liu, Yajing Yuan, Zhaoliang Shen, Xifan Mei
A novel sandwich-assay electrochemical immunosensor for simultaneous determination of autophagic biomarkers was introduced for the first time, the gold-reduced grapheme oxide nanocomposite (Au/r-GO) set as a good conductive platform with super high specific area, and provided more binding sites for the both antibodies of Beclin-1 and LC3B-II. While Au nanocages (AuNCs) served as good conductive platform to encapsulate a large amount of redox probe and secondary antibodies for signal amplification, due to the abundant reactive oxygen functional groups on its surface...
May 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28505563/ultrasensitive-magnetic-field-assisted-surface-plasmon-resonance-immunoassay-for-human-cardiac-troponin-i
#8
Qiong Wu, Ying Sun, Di Zhang, Shuo Li, Yue Zhang, Pinyi Ma, Yang Yu, Xinghua Wang, Daqian Song
An ultrasensitive surface plasmon resonance (SPR) immunoassay was developed for the specific detection of human cardiac troponin I (cTnI), a principle diagnostic marker for myocardial damage. The thin gold film evaporated on a glass slate, which was employed as the SPR sensing film, was modified by hollow gold nanoparticles (HGNPs) and polydopamine (PDA) sequentially, and then was immobilized with antibodies for specific recognition of target analyte. Electronic coupling of the surface plasmon waves originating from the HGNPs and the gold film leads to the remarkable amplification of SPR response...
May 12, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28495100/ultrasensitive-direct-competitive-flisa-using-highly-luminescent-quantum-dot-beads-for-tuning-affinity-of-competing-antigens-to-antibodies
#9
Sicheng Xiong, Yaofeng Zhou, Xiaolin Huang, Ruijin Yu, Weihua Lai, Yonghua Xiong
Herein, for the first time we report a novel direct competitive fluorescence-linked immunosorbent assay (dcFLISA) for the ultrasensitive detection of ochratoxin A (OTA) by introducing a large size polymer beads loaded with quantum dots (QBs) as carrier of competing antigen for decreasing binding affinity to antibody and enhancing the fluorescent signal intensity. When using 255 nm QBs as carrier of competing antigen, the equilibrium dissociation constant of QB based competing antigen to antibodies can be tuned to 100 times higher than that of the horseradish peroxidase (HRP) based competing antigen by controlling labeled amounts of antigen on the surface of QBs...
June 15, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28488883/ultrasensitive-bioanalysis-current-status-and-future-trends
#10
Stéphanie Simon, Eric Ezan
Ligand-binding techniques such as immunoassays, the reference for clinical diagnosis, offer a wide range of innovative approaches based on signal DNA amplification, nanotechnologies or digital assays, which result in technologies with sensitivities more than 1000-times that of formats used 20 years ago. Providing that these technologies gain acceptance and translate into robust commercial platforms, we expect that several fields will be impacted in the near future, including the clinical diagnosis of cancer markers, the early detection of infectious diseases and the safety of biotherapeutics...
May 2017: Bioanalysis
https://www.readbyqxmd.com/read/28483527/immuno-pcr-with-digital-readout
#11
Hendrik Schröder, Maximilian Grösche, Michael Adler, Mark Spengler, Christof M Niemeyer
Immuno-PCR (IPCR) combines the versatile ELISA antigen detection with ultrasensitive PCR signal amplification, thereby enabling the highly sensitive detection of a broad range of targets with a typically very large dynamic detection range. The quantification of the antigen is usually achieved by real-time PCR, which provides a correlation between the target concentration and amplified DNA marker. We here report on the implementation of digital droplet PCR as a means for direct quantification of DNA copies to enable the highly sensitive detection of protein biomarkers...
May 5, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28467848/automated-microfluidic-droplet-based-sample-chopper-for-detection-of-small-fluorescence-differences-using-lock-in-analysis
#12
Jean T Negou, L Adriana Avila, Xiangpeng Li, Tesfagebriel M Hagos, Christopher J Easley
Fluorescence is widely used for small-volume analysis and is a primary tool for on-chip detection in microfluidic devices, yet additional expertise, more elaborate optics, and phase-locked detectors are needed for ultrasensitive measurements. Recently, we designed a microfluidic analog to an optical beam chopper (μChopper) that alternated formation of picoliter volume sample and reference droplets. Without complex optics, the device negated large signal drifts (1/f noise), allowing absorbance detection in a mere 27 μm optical path...
June 6, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28460522/nanobody-based-immunoassay-for-human-soluble-epoxide-hydrolase-detection-using-polymeric-horseradish-peroxidase-polyhrp-for-signal-enhancement-the-rediscovery-of-polyhrp
#13
Dongyang Li, Yongliang Cui, Christophe Morisseau, Shirley J Gee, Candace S Bever, Xiangjiang Liu, Jian Wu, Bruce D Hammock, Yibin Ying
Soluble epoxide hydrolase (sEH) is a potential pharmacological target for treating hypertension, vascular inflammation, cancer, pain, and multiple cardiovascular related diseases. A variable domain of the heavy chain antibody (termed single domain antibody (sdAb), nanobody, or VHH) possesses the advantages of small size, high stability, ease of genetic manipulation, and ability for continuous manufacture, making such nanobody a superior choice as an immunoreagent. In this work, we developed an ultrasensitive nanobody based immunoassay for human sEH detection using polymeric horseradish peroxidase (PolyHRP) for signal enhancement...
June 6, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28451145/competitive-method-based-electrochemiluminescent-assay-with-protein-nucleotide-conversion-for-ratio-detection-to-efficiently-monitor-the-drug-resistance-of-cancer-cells
#14
Wen-Bin Liang, Ming-Zhen Yang, Ying Zhuo, Ying-Ning Zheng, Cheng-Yi Xiong, Ya-Qin Chai, Ruo Yuan
A simple and highly-efficient approach to monitor the expression of P-glycoprotein (P-gp) in cells was urgently needed to demonstrate the drug resistance of cancer cells. Herein, a competitive method-based electrochemiluminescent (ECL) assay with a single ECL indicator was proposed for the first time to efficiently estimate the concentration ratio of two proteins. By converting the different proteins to partially coincident nucleotide sequences via a sandwich type immunoassay on magnetic beads, the concentration ratio related ECL signals could be obtained via competitive nucleotide hybridization on an electrode surface...
December 1, 2016: Chemical Science
https://www.readbyqxmd.com/read/28450781/simple-and-effective-label-free-electrochemical-immunoassay-for-carbohydrate-antigen-19-9-based-on-polythionine-au-composites-as-enhanced-sensing-signals-for-detecting-different-clinical-samples
#15
Zhengjun Huang, Zhouqian Jiang, Chengfei Zhao, Wendi Han, Liqing Lin, Ailin Liu, Shaohuang Weng, Xinhua Lin
Carbohydrate antigen 19-9 (CA19-9) is an important biomarker for the early diagnosis and clinical monitoring of pancreatic cancer. Reliable, simple, and accurate methods for the detection of CA19-9 are still urgently needed. In this study, polythionine-Au composites (AuNPs@ PThi) were designed and prepared through one-pot reaction using HAuCl4 as the co-oxidant and raw material in thionine solution containing FeCl3 as the oxidant. AuNPs@PThi-immobilized glassy carbon electrode was used as a sensitive redox probe for electrochemical interface...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28443852/a-biosensor-based-on-self-clickable-aiegen-a-signal-amplification-strategy-for-ultrasensitive-immunoassays
#16
Youyong Yuan, Wenbo Wu, Shidang Xu, Bin Liu
A signal amplified fluorogenic ELISA based on self-clickable fluorogens with aggregation-induced emission characteristics (AIEgen) as a substrate was developed for ultrasensitive immunoassay.
May 9, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28438806/emerging-affinity-based-proteomic-technologies-for-large-scale-plasma-profiling-in-cardiovascular-disease
#17
REVIEW
J Gustav Smith, Robert E Gerszten
Plasma biomarkers that reflect molecular states of the cardiovascular system are central for clinical decision making. Routinely used plasma biomarkers include troponins, natriuretic peptides, and lipoprotein particles, yet interrogate only a modest subset of pathways relevant to cardiovascular disease. Systematic profiling of a larger portion of circulating plasma proteins (the plasma proteome) will provide opportunities for unbiased discovery of novel markers to improve diagnostic or predictive accuracy. In addition, proteomic profiling may inform pathophysiological understanding and point to novel therapeutic targets...
April 25, 2017: Circulation
https://www.readbyqxmd.com/read/28432339/multifunctional-substrate-of-label-free-electrochemical-immunosensor-for-ultrasensitive-detection-of-cytokeratins-antigen-21-1
#18
Huiqiang Wang, Xin Gao, Zhanfang Ma
Poly(thionine)-Au, a novel multifunctional substrate with excellent redox signal, enzyme-like activity, and easy antibody immobilisation, was synthesised using HAuCl4 as the oxidising agent and thionine as the monomer. The prepared poly(thionine)-Au composite exhibited an admirable electrochemical redox signal at -0.15 V and excellent H2O2 catalytic ability. In addition, gold nanoparticles in this composite were found to directly immobilise antibodies and further improve conductivity. In addition, a label-free electrochemical immunosensor was developed using poly(thionine)-Au as the sensing substrate for ultrasensitive detection of cytokeratin antigen 21-1 (CYFRA 21-1), an immunoassay found in human serum...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28411532/one-pot-loading-high-content-thionine-on-polydopamine-functionalized-mesoporous-silica-nanosphere-for-ultrasensitive-electrochemical-immunoassay
#19
Guosong Lai, Min Zheng, Wenjie Hu, Aimin Yu
A thionine (TH)-doped mesoporous silica nanosphere (MSN)/polydopamine (PDA) nanocomposite was synthesized for developing a new signal transduction strategy of electrochemical immunoassay. This nanocomposite was synthesized through one-pot loading of TH and in situ formation of PDA-coating on MSN. After antibody labeling, the obtained nanoprobe was used for the signal tracing of sandwich immunoassay at a magnetic bead-assay platform. Based on the specific capture of the MSN-TH/PDA nanoprobes through sandwich immunoreaction to form a magnetic immunocomplex and the following treatment of the immunocomplex with a NaOH solution, the PDA film coated on MSN was destroyed to release TH tags from the nanoprobe...
September 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28411223/modified-bacteriophage-s16-long-tail-fiber-proteins-for-rapid-and-specific-immobilization-and-detection-of-salmonella-cells
#20
Jenna M Denyes, Matthew Dunne, Stanislava Steiner, Maximilian Mittelviefhaus, Agnes Weiss, Herbert Schmidt, Jochen Klumpp, Martin J Loessner
Bacteriophage-based assays and biosensors rival traditional antibody-based immunoassays for detection of low-level Salmonella contaminations. In this study, we harnessed the binding specificity of the long tail fiber (LTF) from bacteriophage S16 as an affinity molecule for the immobilization, enrichment, and detection of Salmonella We demonstrate that paramagnetic beads (MBs) coated with recombinant gp37-gp38 LTF complexes (LTF-MBs) are highly effective tools for rapid affinity magnetic separation and enrichment of Salmonella Within 45 min, the LTF-MBs consistently captured over 95% of Salmonella enterica serovar Typhimurium cells from suspensions containing from 10 to 10(5) CFU · ml(-1), and they yielded equivalent recovery rates (93% ± 5%, n = 10) for other Salmonella strains tested...
June 15, 2017: Applied and Environmental Microbiology
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