The Experts below are selected from a list of 2856 Experts worldwide ranked by ideXlab platform
Cb Fuh - One of the best experts on this subject based on the ideXlab platform.
-
Determination of hepatitis B surface antigen using Magnetic Immunoassays in a thin channel
ELSEVIER ADVANCED TECHNOLOGY, 2020Co-Authors: Cb FuhAbstract:[[abstract]]We report novel methods for detection of hepatitis B surface antigen (HBsAg) based on competitive and sandwiched Magnetic Immunoassays using functional Magnetic nanoparticles in a thin channel. Magnetic nanoparticles labeled with hepatitis B antibody are flowed through a thin channel to form a predeposition layer for capturing HBsAg. Competitive and sandwiched Magnetic Immunoassays were studied and detection limit, linear range, and sample selectivity were compared. The detection limits of competitive and sandwiched Magnetic Immunoassays were found to be 0.26 and 0.25 pg/ml, respectively. The linear range of HBsAg concentration was 0.26 pg/ml-2.6 ng/ml for competitive Magnetic Immunoassay and was 0.89 pg/ml-8.9 ng/ml for sandwiched Magnetic Immunoassay. The advantages of these methods over ELISA and other methods for HBsAg detection are lower detection limits and wider linear ranges. The running time was less than 30 min. Competitive Magnetic Immunoassay was faster than sandwiched Magnetic Immunoassay for detection of HBsAg. The measurements of HBsAg in serum samples from these methods differed by about 10% from those of ELISA. These methods can provide simple, fast, and sensitive detections of biomarkers and other Immunoassay-related samples. (C) 2010 Elsevier B.V. All rights reserved.[[note]]SC
-
Effects of particle characteristics on Magnetic Immunoassay in a thin channel
ELSEVIER ADVANCED TECHNOLOGY, 2020Co-Authors: Cb FuhAbstract:[[abstract]]The effects of size and porosity of particles on Magnetic Immunoassay in a thin channel were studied. Experimental parameters were investigated and compared using a model Immunoassay complex of carcinoembryonic antigen (CEA)/anti-CEA. The rate constant for the affinity reaction between functional particles increased as the size of Magnetic nanoparticles (800-80 nm) decreased. The affinity reaction between functional particles had no significant effect on the sizes of microparticles (1.0-4.4 mu m) at commonly used thin channel flow-rates of 0.001-0.025 ml/min. Competitive and sandwich reactions of CEA/anti-CEA were studied for CEA detection. Microparticles of different porosities produced similar linear ranges of detection and limits of detection. The limits of detection for CEA were 0.29 pg/ml and 0.21 pg/ml for competitive and sandwich reactions, respectively. The linear ranges of detection were from 0.49 pg/ml to 4.9 ng/ml for both competitive and sandwich reactions. The detection limits were lower, and the linear ranges were wider than those of literature. There was a 9% difference in CEA detection measurements between competitive and sandwich Magnetic Immunoassay. The measurements of two Magnetic Immunoassays differed by less than 13% from the ELISA reference measurements. The running time was less than 30 min. Magnetic Immunoassay in a thin channel has great potential for biochemical analysis and Immunoassay-related applications. (C) 2011 Elsevier B.V. All rights reserved.[[note]]SC
-
Magnetic Immunoassay detection of tumor necrosis factor-alpha in different deposited zones of thin channels using functional particles
ELSEVIER SCIENCE SA, 2020Co-Authors: Cb FuhAbstract:[[abstract]]This study reports the Magnetic Immunoassay detection of tumor necrosis factor-alpha (TNF-alpha) in different deposited zones of thin channels using functional particles. Deposited zones with linear and s-shape geometries were tested and compared to detect a TNF-alpha model biomarker. Results show that the deposited zone of s-shape geometry is faster than that of linear geometry for affinity reactions. Using the s-shape deposited zones, the running time can be reduced to less than 20 min. The detection limits of linear and s-shape deposited zones were found to be the same as 1.0 pg/mL within experimental errors. The detection limit is lower than that of ELISA. The linear ranges of TNF-alpha detection were from 1.7 pg/mL to 1.7 ng/mL for two deposited zones in sandwiched Magnetic Immunoassay. The linear range of this method is wider than those of ELISA and other methods. The measurements of TNF-alpha in serum samples from this method differed from ELISA results by about 10%. The proposed method can provide simple, fast, and sensitive detection for biomarkers. (C) 2012 Elsevier B.V. All rights reserved.[[note]]SC
-
Detection of alpha-fetoprotein in Magnetic Immunoassay of thin channels using biofunctional nanoparticles
'Springer Fachmedien Wiesbaden GmbH', 2020Co-Authors: Cb FuhAbstract:[[abstract]]This paper presents the use of fluorescent biofunctional nanoparticles (10-30 nm) to detect alpha-fetoprotein (AFP) in a thin-channel Magnetic Immunoassay. We used an AFP model biomarker and s-shaped deposition zones to test the proposed detection method. The results show that the detection using fluorescent biofunctional nanoparticle has a higher throughput than that of functional microparticle used in previous experiments on affinity reactions. The proposed method takes about 3 min (versus 150 min of previous method) to detect 100 samples. The proposed method is useful for screening biomarkers in clinical applications, and can reduce the run time for sandwich Immunoassays to less than 20 min. The detection limits (0.06 pg/ml) and linear ranges (0.068 pg/ml-0.68 ng/ml) of AFP using fluorescent biofunctional nanoparticles are the same as those of using functional microparticles within experimental errors. This detection limit is substantially lower and the linear range is considerably wider than those of enzyme-linked immunosorbent assay (ELISA) and other methods in sandwich Immunoassay methods. The differences between this method and an ELISA in AFP measurements of serum samples were less than 12 %. The proposed method provides simple, fast, and sensitive detection with a high throughput for biomarkers.[[note]]SC
-
Competitive Magnetic Immunoassay for protein detection in thin channels
ELSEVIER SCIENCE BV, 2020Co-Authors: Cb FuhAbstract:[[abstract]]Functional Magnetic nanoparticles are prepared and characterized for protein detection in a Magnetic separation channel This detection method is based on a competitive Immunoassay of Magnetic separation in thin channels using functional Magnetic nanoparticles. We used protein A-IgG complex to demonstrate the feasibility. Free IgG and fixed number of IgG-labeled microparticles were used to compete for limited sites of protein A on the Magnetic nanoparticles. Several experimental parameters were investigated for protein detection The deposited percentages of IgG-labeled microparticles at various concentrations of free IgG were deter mined and Used as a reference plot. The IgG concentration in a sample was deduced and determined based oil the reference plot using the deposited percentage of IgG-labeled microparticles from the sample The linear range of IgG detection was from 5.0 x 10(-8) to 1.0 x 10(-11) M The detection limit was 3.69 x 10(-12) M The running time was less than 10 min Selectivities were higher than 92% and the relative errors were less than 7%. The IgG concentration of serum was determined to be 3.6 mg ml(-1) This measurement differed by 8.3% from the ELISA measurement The recoveries of IgG spiked in serum were found to be higher-than 94%. This method can provide simple, fast, and selective analysis for protein detection and other Immunoassay-related applications (C) 2009 Elsevier B.V. All rights reserved.[[note]]SC
John X J Zhang - One of the best experts on this subject based on the ideXlab platform.
-
microscale Magnetic field modulation for enhanced capture and distribution of rare circulating tumor cells
Scientific Reports, 2015Co-Authors: Peng Chen, Yu Yen Huang, Kazunori Hoshino, John X J ZhangAbstract:ImmunoMagnetic assay combines the powers of the Magnetic separation and biomarker recognition and has been an effective tool to perform rare Circulating Tumor Cells detection. Key factors associated with immunoMagnetic assay include the capture rate, which indicates the sensitivity of the system and distributions of target cells after capture, which impact the cell integrity and other biological properties that are critical to downstream analyses. Here we present a theoretical framework and technical approach to implement a microscale Magnetic Immunoassay through modulating local Magnetic field towards enhanced capture and distribution of rare cancer cells. Through the design of a two-dimensional micromagnet array, we characterize the Magnetic field generation and quantify the impact of the micromagnets on rare cell separation. Good agreement is achieved between the theory and experiments using a human colon cancer cell line (COLO205) as the capture targets.
Xing Zhang - One of the best experts on this subject based on the ideXlab platform.
-
nanoparticle labelling based Magnetic Immunoassay on chip combined with electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of carcinoembryonic antigen in human serum
Analyst, 2011Co-Authors: Beibei Chen, Hanyong Peng, Man He, Bin Hu, Ping Jiang, Xing ZhangAbstract:A sensitive and selective on chip Magnetic Immunoassay method, based on a sandwich-type immunoreaction with PbS nanoparticle (NPs) labels in combination with electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS), was proposed for the determination of carcinoembryonic antigen (CEA). We designed and fabricated a microfluidic chip for Magnetic Immunoassay, and the prepared iminodiacetic acid modified silica coated Magnetic nanoparticles (IDA-SCMNPs) were packed into the central microchannel to form a solid phase column by self-assembly under the Magnetic field. After completion of the immunoreaction involving a primary antibody, CEA and a secondary antibody labeled with PbS NPs on a Magnetic solid phase packed-column, ETV-ICP-MS was used to determine the concentration of Pb that was released from the captured PbS NPs using an acid-dissolution step. The concentrations of CEA can be correlated with that of Pb. The established method demonstrated a limit of detection of 0.058 μg L−1 for CEA, with a relative standard deviation (RSD) of 6.7% (c = 10 μg L−1, n = 7). A linearity ranging from 0.2 μg L−1 to 50 μg L−1 and a 2-fold enrichment factor (from 60 μL sample solution to 30 μL eluent) were achieved. The proposed method was further validated by analyzing CEA in human serum. The results were in good agreement with those obtained by chemiluminescent Immunoassay, which is currently used as a clinical method. Overall, this method offers the advantages of high speed, high sensitivity, high selectivity, low sample/reagents consumption, high integrity and versatility. Moreover, it can be easily applied to other biological and medical assays.
Chong H. Ahn - One of the best experts on this subject based on the ideXlab platform.
-
A polymer lab-on-a-chip for Magnetic Immunoassay with on-chip sampling and detection capabilities
Lab on a Chip, 2008Co-Authors: Jaephil Do, Chong H. AhnAbstract:This paper presents a new polymer lab-on-a-chip for Magnetic bead-based Immunoassay with fully on-chip sampling and detection capabilities, which provides a smart platform of Magnetic Immunoassay-based lab-on-a-chip for point-of-care testing (POCT) toward biochemical hazardous agent detection, food inspection or clinical diagnostics. In this new approach, the polymer lab-on-a-chip for Magnetic bead-based Immunoassay consists of a Magnetic bead-based separator, an interdigitated array (IDA) micro electrode, and a microfluidic system, which are fully incorporated into a lab-on-a-chip on cyclic olefin copolymer (COC). Since the polymer lab-on-a-chip was realized using low cost, high throughput polymer microfabrication techniques such as micro injection molding and hot embossing method, a disposable polymer lab-on-a-chip for the Magnetic bead-based Immunoassay can be successfully realized in a disposable platform. With this newly developed polymer lab-on-a-chip, an enzyme-labelled electrochemical Immunoassay (ECIA) was performed using Magnetic beads as the mobile solid support, and the final enzyme product produced from the ECIA was measured using chronoamperometry. A sampling and detection of as low as 16.4 ng mL−1 of mouse IgG has been successfully performed in 35 min for the entire procedure.
Peng Chen - One of the best experts on this subject based on the ideXlab platform.
-
microscale Magnetic field modulation for enhanced capture and distribution of rare circulating tumor cells
Scientific Reports, 2015Co-Authors: Peng Chen, Yu Yen Huang, Kazunori Hoshino, John X J ZhangAbstract:ImmunoMagnetic assay combines the powers of the Magnetic separation and biomarker recognition and has been an effective tool to perform rare Circulating Tumor Cells detection. Key factors associated with immunoMagnetic assay include the capture rate, which indicates the sensitivity of the system and distributions of target cells after capture, which impact the cell integrity and other biological properties that are critical to downstream analyses. Here we present a theoretical framework and technical approach to implement a microscale Magnetic Immunoassay through modulating local Magnetic field towards enhanced capture and distribution of rare cancer cells. Through the design of a two-dimensional micromagnet array, we characterize the Magnetic field generation and quantify the impact of the micromagnets on rare cell separation. Good agreement is achieved between the theory and experiments using a human colon cancer cell line (COLO205) as the capture targets.
