scholarly journals Magnetic Control of an Electrochemical Microfluidic Device with an Arrayed Immunosensor for Simultaneous Multiple Immunoassays

2007 ◽  
Vol 53 (7) ◽  
pp. 1323-1329 ◽  
Author(s):  
Dianping Tang ◽  
Ruo Yuan ◽  
Yaqin Chai
Keyword(s):  
Tumor Markers ◽  
Microfluidic Device ◽  
Simultaneous Detection ◽  
Reference Electrode ◽  
Cost Effective ◽  
Sio2 Nanoparticles ◽  
Magnetic Bead ◽  
Label Free ◽  
Specific Tumor ◽  
Protein Diagnostics

Abstract Background: Methods based on magnetic bead probes have been developed for immunoassay, but most involve complicated labeling or stripping procedures and are unsuitable for routine use. Methods: We synthesized magnet core/shell NiFe2O4/SiO2 nanoparticles and fabricated an electrochemical magnetic controlled microfluidic device for the detection of 4 tumor markers. The immunoassay system consisted of 5 working electrodes and an Ag/AgCl reference electrode integrated on a glass substrate. Each working electrode contained a different antibody immobilized on the NiFe2O4/SiO2 nanoparticle surface and was capable of measuring a specific tumor marker using noncompetitive electrochemical immunoassay. Results: Under optimal conditions, the multiplex immunoassay enabled the simultaneous detection of 4 tumor markers. The sensor detection limit was <0.5 μg/L (or <0.5 kunits/L) for most analytes. Intra- and interassay imprecisions (CVs) were <4.5% and 8.7% for analyte concentrations >5 μg/L (or >5 kunits/L), respectively. No nonspecific adsorption was observed during a series of procedures to detect target proteins, and electrochemical cross-talk (CV) between neighboring sites was <10%. Conclusion: This immunoassay system offers promise for label-free, rapid, simple, cost-effective analysis of biological samples. Importantly, the chip-based immunosensor could be suitable for use in the mass production of miniaturized lab-on-a-chip devices and open new opportunities for protein diagnostics and biosecurity.

scholarly journals High throughput hemogram of T cells using digital holographic microscopy and deep learning

2021 ◽  
Author(s):  
Roopam K Gupta ◽  
Nils Hempler ◽  
Graeme Malcolm ◽  
Kishan Dholakia ◽  
Simon J Powis
Keyword(s):  
T Cells ◽  
Deep Learning ◽  
Adaptive Immune System ◽  
Cost Effective ◽  
Magnetic Bead ◽  
T Cell Subsets ◽  
Digital Holographic Microscopy ◽  
Label Free ◽  
Throughput Rate ◽  
Holographic Microscopy

T cells of the adaptive immune system provide effective protection to the human body against numerous pathogenic challenges. Current labelling methods of detecting these cells, such as flow cytometry or magnetic bead labelling, are time consuming and expensive. To overcome these limitations, the label-free method of digital holographic microscopy (DHM) combined with deep learning has recently been introduced which is both time and cost effective. In this study, we demonstrate the application of digital holographic microscopy with deep learning to classify the key CD4+ and CD8+ T cell subsets. We show that combining DHM of varying fields of view, with deep learning, can potentially achieve a classification throughput rate of 78,000 cells per second with an accuracy of 76.2% for these morphologically similar cells. This throughput rate is 100 times faster than the previous studies and proves to be an effective replacement for labelling methods.

Nanomechanical Sensor Array for Detection of Biomolecular Bindings: Toward a Label-Free Clinical Assay for Serum Tumor Markers

2004 ◽  
Author(s):  
Min Yue ◽  
Jeanne C. Stachowiak ◽  
Henry Lin ◽  
Kenneth Castelino ◽  
Ram Datar ◽  
...  
Keyword(s):  
Tumor Markers ◽  
Cost Effective ◽  
Label Free ◽  
Serum Tumor Markers ◽  
Cantilever Sensors ◽  
Clinical Assay ◽  
Diagnosis Of Cancer ◽  
Coated Surface ◽  
Effective Diagnosis ◽  
Antigen Antibody

A label-free technique capable of rapidly screening human blood samples simultaneously for multiple serum tumor markers would enable accurate and cost-effective diagnosis of cancer before physiological symptoms appear. Recently, microfabricated, bimaterial cantilever sensors have been demonstrated to detect DNA hybridization and antigen-antibody binding at clinically relevant concentrations. Cantilever sensors deflect measurably under the surface stress resulting when biomolecules immobilized on one surface of the sensor interact with their binding partners [1]. We present an array of cantilever sensors (silicon nitride with a gold coated surface) capable of simultaneously interrogating 100 different biomolecular interactions.

Detection of Tumor Markers Using Single-Walled Carbon Nanotube Field Effect Transistors

2006 ◽  
Vol 6 (11) ◽  
pp. 3499-3502 ◽  
Author(s):  
Dong-Won Park ◽  
Yo-Han Kim ◽  
Beom Soo Kim ◽  
Hye-Mi So ◽  
Keehoon Won ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Tumor Markers ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Sharp Decrease ◽  
Tween 20 ◽  
Label Free ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Specific Tumor

We have developed a biosensor capable of detecting carcinoembryonic antigen (CEA) markers using single-walled carbon nanotube field effect transistors (SWNT-FETs). These SWNT-FETs were fabricated using nanotubes produced by a patterned catalyst growth technique, where the top contact electrodes were generated using conventional photolithography. For biosensor applications, SU-8 negative photoresist patterns were used as an insulation layer. CEA antibodies were employed as recognition elements to specific tumor markers, and were successfully immobilized on the sides of a single-walled carbon nanotube using CDI-Tween 20 linking molecules. The binding of tumor markers to these antibody-functionalized SWNT-FETs was then monitored continuously during exposure to dilute CEA solutions. The observed sharp decrease in conductance demonstrates the possibility of realizing highly sensitive, label-free SWNT-FET-based tumor sensors.

scholarly journals Precise and label-free tumour cell recognition based on a black phosphorus nanoquenching platform

2018 ◽  
Vol 6 (35) ◽  
pp. 5613-5620 ◽  
Author(s):  
Wujuan Yan ◽  
Xiu-Hong Wang ◽  
Jingwen Yu ◽  
Xiaotong Meng ◽  
Pengfei Qiao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Tumor Markers ◽  
Tumour Cell ◽  
Breast Cancer Cells ◽  
Simultaneous Detection ◽  
Black Phosphorus ◽  
Cell Recognition ◽  
Label Free

Duplexed recognition of label-free breast cancer cells: a duplexed assay platform based on a BP nanoquencher allows simultaneous detection of two tumor markers within one run.

A microfluidic device with integrated impedance detection for λ-DNA

2003 ◽  
Vol 773 ◽  
Author(s):  
Myung-Il Park ◽  
Jonging Hong ◽  
Dae Sung Yoon ◽  
Chong-Ook Park ◽  
Geunbae Im
Keyword(s):  
Microfluidic Device ◽  
Electrochemical Impedance ◽  
Direct Detection ◽  
Full Potential ◽  
Label Free ◽  
Buffer Solution ◽  
Detection Systems ◽  
Significant Difference ◽  
Detection Of Biomolecules ◽  
Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

scholarly journals Titanium Nitride Thin Film Based Low-Redox-Interference Potentiometric pH Sensing Electrodes

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 42
Author(s):  
Shimrith Paul Shylendra ◽  
Wade Lonsdale ◽  
Magdalena Wajrak ◽  
Mohammad Nur-E-Alam ◽  
Kamal Alameh
Keyword(s):  
Thin Film ◽  
Titanium Nitride ◽  
Orange Juice ◽  
Ph Sensor ◽  
Reference Electrode ◽  
Cost Effective ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Potential Shift ◽  
Double Junction

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of −59.1 mV/pH, R2 = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/h. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO2) counterparts. Experimental results show −32 mV potential shift (E0 value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the −114 mV potential shift of IrO2 electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

scholarly journals Utilising Commercially Fabricated Printed Circuit Boards as an Electrochemical Biosensing Platform

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 793
Author(s):  
Uroš Zupančič ◽  
Joshua Rainbow ◽  
Pedro Estrela ◽  
Despina Moschou
Keyword(s):  
Printed Circuit Boards ◽  
Electrochemical Sensors ◽  
Cost Effective ◽  
Electrochemical Sensing ◽  
Label Free ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Sensing Applications ◽  
Electrochemical Biosensing ◽  
Pre Treatment

Printed circuit boards (PCBs) offer a promising platform for the development of electronics-assisted biomedical diagnostic sensors and microsystems. The long-standing industrial basis offers distinctive advantages for cost-effective, reproducible, and easily integrated sample-in-answer-out diagnostic microsystems. Nonetheless, the commercial techniques used in the fabrication of PCBs produce various contaminants potentially degrading severely their stability and repeatability in electrochemical sensing applications. Herein, we analyse for the first time such critical technological considerations, allowing the exploitation of commercial PCB platforms as reliable electrochemical sensing platforms. The presented electrochemical and physical characterisation data reveal clear evidence of both organic and inorganic sensing electrode surface contaminants, which can be removed using various pre-cleaning techniques. We demonstrate that, following such pre-treatment rules, PCB-based electrodes can be reliably fabricated for sensitive electrochemical biosensors. Herein, we demonstrate the applicability of the methodology both for labelled protein (procalcitonin) and label-free nucleic acid (E. coli-specific DNA) biomarker quantification, with observed limits of detection (LoD) of 2 pM and 110 pM, respectively. The proposed optimisation of surface pre-treatment is critical in the development of robust and sensitive PCB-based electrochemical sensors for both clinical and environmental diagnostics and monitoring applications.

Plasma enhanced label-free immunoassay for alpha-fetoprotein based on a U-bend fiber-optic LSPR biosensor

RSC Advances ◽  
2015 ◽  
Vol 5 (31) ◽  
pp. 23990-23998 ◽  
Author(s):  
Gaoling Liang ◽  
Zhongjun Zhao ◽  
Yin Wei ◽  
Kunping Liu ◽  
Wenqian Hou ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Fiber Optic ◽  
Cost Effective ◽  
Alpha Fetoprotein ◽  
Localized Surface Plasmon ◽  
Label Free

A simple, label-free and cost-effective localized surface plasmon resonance (LSPR) immunosensing method was developed for detection of alpha-fetoprotein (AFP).

scholarly journals Microsphere-Based Microfluidic Device for Plasma Separation and Potential Biochemistry Analysis Applications

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 487
Author(s):  
Hongyan Xu ◽  
Zhangying Wu ◽  
Jinan Deng ◽  
Jun Qiu ◽  
Ning Hu ◽  
...  
Keyword(s):  
Blood Sample ◽  
Microfluidic Device ◽  
Biochemical Analysis ◽  
Cost Effective ◽  
Clinical Diagnostics ◽  
Correction Factors ◽  
Separation Device ◽  
Blood Samples ◽  
Plasma Separation ◽  
Blood Biochemical

The development of a simple, portable, and cost-effective plasma separation platform for blood biochemical analysis is of great interest in clinical diagnostics. We represent a plasma separation microfluidic device using microspheres with different sizes as the separation barrier. This plasma separation device, with 18 capillary microchannels, can extract about 3 μL of plasma from a 50 μL blood sample in about 55 min. The effects of evaporation and the microsphere barrier on the plasma biochemical analysis results were studied. Correction factors were applied to compensate for these two effects. The feasibility of the device in plasma biochemical analysis was validated with clinical blood samples.

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