scholarly journals Label-free viscosity measurement of complex fluids using reversal flow switching manipulation in a microfluidic channel

2013 ◽  
Vol 7 (4) ◽  
pp. 044106 ◽  
Author(s):  
Yang Jun Kang ◽  
Jeongeun Ryu ◽  
Sang-Joon Lee
Keyword(s):  
Complex Fluids ◽  
Microfluidic Channel ◽  
Viscosity Measurement ◽  
Label Free ◽  
Reversal Flow

scholarly journals Differential Sorting of Microparticles Using Spiral Microchannels with Elliptic Configurations

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 412
Author(s):  
Kaan Erdem ◽  
Vahid Ebrahimpour Ahmadi ◽  
Ali Kosar ◽  
Lütfullah Kuddusi
Keyword(s):  
Cell Sorting ◽  
Microfluidic Channel ◽  
Major Axis ◽  
Label Free ◽  
Flow Rates ◽  
Inertial Focusing ◽  
Size Dependent ◽  
Curved Channels ◽  
Aspect Ratios ◽  
Dependent Cell

Label-free, size-dependent cell-sorting applications based on inertial focusing phenomena have attracted much interest during the last decade. The separation capability heavily depends on the precision of microparticle focusing. In this study, five-loop spiral microchannels with a height of 90 µm and a width of 500 µm are introduced. Unlike their original spiral counterparts, these channels have elliptic configurations of varying initial aspect ratios, namely major axis to minor axis ratios of 3:2, 11:9, 9:11, and 2:3. Accordingly, the curvature of these configurations increases in a curvilinear manner through the channel. The effects of the alternating curvature and channel Reynolds number on the focusing of fluorescent microparticles with sizes of 10 and 20 µm in the prepared suspensions were investigated. At volumetric flow rates between 0.5 and 3.5 mL/min (allowing separation), each channel was tested to collect samples at the designated outlets. Then, these samples were analyzed by counting the particles. These curved channels were capable of separating 20 and 10 µm particles with total yields up to approximately 95% and 90%, respectively. The results exhibited that the level of enrichment and the focusing behavior of the proposed configurations are promising compared to the existing microfluidic channel configurations.

scholarly journals Cellular lensing and near infrared fluorescent nanosensor arrays to enable chemical efflux cytometry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Soo-Yeon Cho ◽  
Xun Gong ◽  
Volodymyr B. Koman ◽  
Matthias Kuehne ◽  
Sun Jin Moon ◽  
...  
Keyword(s):  
Near Infrared ◽  
Single Cells ◽  
Microfluidic Channel ◽  
Human Monocyte ◽  
Cellular Heterogeneity ◽  
Label Free ◽  
Nanotube Array ◽  
Chemical Cytometry ◽  
Rich Information ◽  
Non Destructive

AbstractNanosensors have proven to be powerful tools to monitor single cells, achieving spatiotemporal precision even at molecular level. However, there has not been way of extending this approach to statistically relevant numbers of living cells. Herein, we design and fabricate nanosensor array in microfluidics that addresses this limitation, creating a Nanosensor Chemical Cytometry (NCC). nIR fluorescent carbon nanotube array is integrated along microfluidic channel through which flowing cells is guided. We can utilize the flowing cell itself as highly informative Gaussian lenses projecting nIR profiles and extract rich information. This unique biophotonic waveguide allows for quantified cross-correlation of biomolecular information with various physical properties and creates label-free chemical cytometer for cellular heterogeneity measurement. As an example, the NCC can profile the immune heterogeneities of human monocyte populations at attomolar sensitivity in completely non-destructive and real-time manner with rate of ~600 cells/hr, highest range demonstrated to date for state-of-the-art chemical cytometry.

scholarly journals An infrared sensor analysing label-free the secondary structure of the Abeta peptide in presence of complex fluids

2015 ◽  
Vol 9 (3) ◽  
pp. 224-234 ◽  
Author(s):  
Andreas Nabers ◽  
Julian Ollesch ◽  
Jonas Schartner ◽  
Carsten Kötting ◽  
Just Genius ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Complex Fluids ◽  
Label Free ◽  
Infrared Sensor ◽  
Abeta Peptide

scholarly journals An Aptamer-Based Capacitive Sensing Platform for Specific Detection of Lung Carcinoma Cells in the Microfluidic Chip

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 98 ◽  
Author(s):  
Ngoc-Viet Nguyen ◽  
Chun-Hao Yang ◽  
Chung-Jung Liu ◽  
Chao-Hung Kuo ◽  
Deng-Chyang Wu ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Lung Carcinoma ◽  
Early Stage ◽  
A549 Cells ◽  
Microfluidic Channel ◽  
Electrical Impedance Spectroscopy ◽  
Label Free ◽  
Early Stage Lung Cancer ◽  
Sensing Platform ◽  
Label Free Detection

Improvement of methods for reliable and early diagnosis of the cellular diseases is necessary. A biological selectivity probe, such as an aptamer, is one of the candidate recognition layers that can be used to detect important biomolecules. Lung cancer is currently a typical cause of cancer-related deaths. In this work, an electrical sensing platform is built based on amine-terminated aptamer modified-gold electrodes for the specific, label-free detection of a human lung carcinoma cell line (A549). The microdevice, that includes a coplanar electrodes configuration and a simple microfluidic channel on a glass substrate, is fabricated using standard photolithography and cast molding techniques. A procedure of self-assembly onto the gold surface is proposed. Optical microscope observations and electrical impedance spectroscopy measurements confirm that the fabricated microchip can specifically and effectively identify A549 cells. In the experiments, the capacitance element that is dominant in the change of the impedance is calculated at the appropriate frequency for evaluation of the sensitivity of the biosensor. Therefore, a simple, inexpensive, biocompatible, and selective biosensor that has the potential to detect early-stage lung cancer would be developed.

scholarly journals EGOFET Peptide Aptasensor for Label-Free Detection of Inflammatory Cytokines in Complex Fluids

2017 ◽  
Vol 2 (2) ◽  
pp. 1700072 ◽  
Author(s):  
Marcello Berto ◽  
Chiara Diacci ◽  
Roberta D'Agata ◽  
Marcello Pinti ◽  
Elena Bianchini ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Complex Fluids ◽  
Label Free ◽  
Label Free Detection

Electrical Detection of Protein Biomarkers Using Nanoneedle Biosensors

2012 ◽  
Vol 1414 ◽  
Author(s):  
Rahim Esfandyarpour ◽  
Hesaam Esfandyarpour ◽  
Mehdi Javanmard ◽  
James S. Harris ◽  
Ronald W. Davis
Keyword(s):  
Physical Adsorption ◽  
Ionic Current ◽  
Microfluidic Channel ◽  
Protein Detection ◽  
High Sensitivity ◽  
Receptor Protein ◽  
Label Free ◽  
Electrical Detection ◽  
Protein Biomarkers ◽  
Impedance Modulation

Abstract:Here we present the development of an array of electrical nano-biosensors in a microfluidic channel, called Nanoneedle biosensors. Then we present the proof of concept study for protein detection. A Nanoneedle biosensor is a real-time, label-free, direct electrical detection platform, which is capable of high sensitivity detection, measuring the change in ionic current and impedance modulation, due to the presence or reaction of biomolecules such as proteins or nucleic acids. We show that the sensors which have been fabricated and characterized for the protein detection. We have functionalized Nanoneedle biosensors with receptors specific to a target protein using physical adsorption for immobilization. We have used biotinylated bovine serum albumin as the receptor and sterptavidin as the target analyte. The detection of streptavidin binding to the receptor protein is also presented.

scholarly journals Inertial Microfluidics Enabling Clinical Research

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 257
Author(s):  
Srivathsan Kalyan ◽  
Corinna Torabi ◽  
Harrison Khoo ◽  
Hyun Woo Sung ◽  
Sung-Eun Choi ◽  
...  
Keyword(s):  
Microfluidic Channel ◽  
Relevant Information ◽  
Label Free ◽  
Inertial Microfluidics ◽  
Inertial Focusing ◽  
Viscous Forces ◽  
Solution Exchange ◽  
On Chip ◽  
Improving Accuracy ◽  
Hybrid Devices

Fast and accurate interrogation of complex samples containing diseased cells or pathogens is important to make informed decisions on clinical and public health issues. Inertial microfluidics has been increasingly employed for such investigations to isolate target bioparticles from liquid samples with size and/or deformability-based manipulation. This phenomenon is especially useful for the clinic, owing to its rapid, label-free nature of target enrichment that enables further downstream assays. Inertial microfluidics leverages the principle of inertial focusing, which relies on the balance of inertial and viscous forces on particles to align them into size-dependent laminar streamlines. Several distinct microfluidic channel geometries (e.g., straight, curved, spiral, contraction-expansion array) have been optimized to achieve inertial focusing for a variety of purposes, including particle purification and enrichment, solution exchange, and particle alignment for on-chip assays. In this review, we will discuss how inertial microfluidics technology has contributed to improving accuracy of various assays to provide clinically relevant information. This comprehensive review expands upon studies examining both endogenous and exogenous targets from real-world samples, highlights notable hybrid devices with dual functions, and comments on the evolving outlook of the field.

Integration of a guided-mode resonance filter with microposts for in-cell protein detection

The Analyst ◽  
2016 ◽  
Vol 141 (13) ◽  
pp. 4189-4195 ◽  
Author(s):  
Yi-Kai Tu ◽  
Meng-Zhe Tsai ◽  
I-Chin Lee ◽  
Hsin-Yun Hsu ◽  
Cheng-Sheng Huang
Keyword(s):  
Microfluidic Channel ◽  
Protein Detection ◽  
Cell Protein ◽  
Label Free ◽  
Guided Mode ◽  
Guided Mode Resonance

The integration of a label-free biosensor of a guided-mode resonance filter and a microfluidic channel with a micropost filter.

scholarly journals Using real-time fluorescence and deformability cytometry and deep learning to transfer molecular specificity to label-free sorting

2019 ◽  
Author(s):  
Ahmad Ahsan Nawaz ◽  
Marta Urbanska ◽  
Maik Herbig ◽  
Martin Nötzel ◽  
Martin Kräter ◽  
...  
Keyword(s):  
Real Time ◽  
Acoustic Waves ◽  
Blood Cells ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Cell Types ◽  
Biological Research ◽  
Label Free ◽  
Molecular Specificity ◽  
Deformability Cytometry

The identification and separation of specific cells from heterogeneous populations is an essential prerequisite for further analysis or use. Conventional passive and active separation approaches rely on fluorescent or magnetic tags introduced to the cells of interest through molecular markers. Such labeling is time- and cost-intensive, can alter cellular properties, and might be incompatible with subsequent use, for example, in transplantation. Alternative label-free approaches utilizing morphological or mechanical features are attractive, but lack molecular specificity. Here we combine image-based real-time fluorescence and deformability cytometry (RT-FDC) with downstream cell sorting using standing surface acoustic waves (SSAW). We demonstrate basic sorting capabilities of the device by separating cell mimics and blood cell types based on fluorescence as well as deformability and other image parameters. The identification of blood sub-populations is enhanced by flow alignment and deformation of cells in the microfluidic channel constriction. In addition, the classification of blood cells using established fluorescence-based markers provides hundreds of thousands of labeled cell images used to train a deep neural network. The trained algorithm, with latency optimized to below 1 ms, is then used to identify and sort unlabeled blood cells at rates of 100 cells/sec. This approach transfers molecular specificity into label-free sorting and opens up new possibilities for basic biological research and clinical therapeutic applications.

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