scholarly journals Cover Picture: Microfluidic Device Using a Gold Pillar Array and Integrated Electrodes for On‐chip Endothelial Cell Immobilization, Direct RBC Contact, and Amperometric Detection of Nitric Oxide (Electroanalysis 8/2019)

2019 ◽  
Vol 31 (8) ◽  
Author(s):  
Alexandra D. Townsend ◽  
Randy S. Sprague ◽  
R. Scott Martin
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cell ◽  
Microfluidic Device ◽  
Cell Immobilization ◽  
Amperometric Detection ◽  
Pillar Array ◽  
On Chip

scholarly journals Design and Manufacturing of a Disposable, Cyclo-Olefin Copolymer, Microfluidic Device for a Biosensor †

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1178 ◽  
Author(s):  
Jorge Prada ◽  
Christina Cordes ◽  
Carsten Harms ◽  
Walter Lang
Keyword(s):  
Microfluidic Device ◽  
Heating Temperature ◽  
Low Cost ◽  
Reaction Chamber ◽  
Microfluidic System ◽  
Heating Process ◽  
Design And Manufacturing ◽  
On Chip ◽  
Working Parameters ◽  
Auto Fluorescence

This contribution outlines the design and manufacturing of a microfluidic device implemented as a biosensor for retrieval and detection of bacteria RNA. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and manufacturability by hot-embossing. The RNA retrieval was carried on after bacteria heat-lysis by an on-chip micro-heater, whose function was characterized at different working parameters. Carbon resistive temperature sensors were tested, characterized and printed on the biochip sealing film to monitor the heating process. Off-chip and on-chip processed RNA were hybridized with capture probes on the reaction chamber surface and identification was achieved by detection of fluorescence tags. The application of the mentioned techniques and materials proved to allow the development of low-cost, disposable albeit multi-functional microfluidic system, performing heating, temperature sensing and chemical reaction processes in the same device. By proving its effectiveness, this device contributes a reference to show the integration potential of fully thermoplastic devices in biosensor systems.

Screen-printed graphene-based electrochemical sensors for a microfluidic device

2017 ◽  
Vol 9 (24) ◽  
pp. 3689-3695 ◽  
Author(s):  
C. Karuwan ◽  
A. Wisitsoraat ◽  
P. Chaisuwan ◽  
D. Nacapricha ◽  
A. Tuantranont
Keyword(s):  
Microfluidic Device ◽  
Screen Printing ◽  
Electrochemical Sensors ◽  
Amperometric Detection ◽  
New Method ◽  
Screen Printing Technique ◽  
Printing Technique ◽  
Electrochemical Electrodes ◽  
Screen Printed

This work presents a new method for mass fabrication of a new microfluidic device with integrated graphene-based electrochemical electrodes by the screen printing technique for in-channel amperometric detection.

A Simple Silicon Based Nitric Oxide Sensor

1999 ◽  
Author(s):  
Marcelo Bariatto ◽  
Rogerio Furlan ◽  
Koiti Arakai ◽  
Jorge J. Santiago-Aviles
Keyword(s):  
Nitric Oxide ◽  
Amperometric Detection ◽  
Cellular Level ◽  
High Yield ◽  
Sensor Calibration ◽  
Nitric Oxide Sensor ◽  
Sensor Configuration

Abstract Nitric oxide (NO) is known to mediate many beneficial physiology processes, motivating its detection in vivo as well as in vitro. Electrochemical detection provides the required cellular level determination of NO among several other techniques. In this work, electrochemical micro-sensors for both types of detection, in vivo and in vitro, were developed, exploring the silicon planar technology, which presents high yield and reliability and also permits batch fabrication. The developed in vitro sensor features eight detection sites (10 μm × 10 μm microelectrodes), for determination of nitric oxide spatial distribution or multi-species analysis. Different electrochemical methods were applied to provide sensor calibration and chemical reproducibility. For in vivo analysis, the designed structures have a needle shape (40 μm thick) and they were silicon micro-machined by using plasma etching or etch stop techniques. Different configurations were designed and implemented, containing a number of detection microelectrodes that vary from 2 to 10. The amperometric detection of both nitric oxide and nitride (NO2−) — a molecule that causes an interference — were investigated by using the in vitro micro-sensor configuration. The need of a cationic exchanger (Nafion) was demonstrated in order to provide selectivity to NO for low concentrations. Also, the developed sensor has a sensitivity of 500 A/M.cm2 and a detection limit of 10 μM.

Effects of lipoproteins from pre-eclamptic women on umbilical endothelial cell 6-oxo-prostaglandin F1α and endothelin 1 synthesis, and nitric oxide synthase 3 mRNA expression

1999 ◽  
Vol 97 (6) ◽  
pp. 697-706 ◽  
Author(s):  
A. BARDEN ◽  
L. J. BEILIN ◽  
K. BOTH ◽  
J. RITCHIE ◽  
P. LEEDMAN ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cell ◽  
Nitric Oxide Synthase ◽  
Pregnant Women ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Endothelin 1 ◽  
Nitric Oxide Synthase 3 ◽  
Oxide Synthase

In order to evaluate whether lipid abnormalities may contribute to endothelial dysfunction in pre-eclampsia, the present study examined the in vitro effects of very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), isolated from women with pre-eclampsia and matched controls, on the endothelial synthesis of 6-oxo-prostaglandin F1α (6-oxo-PGF1α; a metabolite of prostacyclin) and endothelin 1, and on the expression of nitric oxide synthase 3 (NOS3) mRNA. VLDL, LDL and HDL cholesterol were isolated from 20 pre-eclamptic and 20 age- and gestation-matched normal pregnant women. The lipoproteins (50 μg/ml) and lipoprotein-free control plasma were incubated for 1, 3 and 6 h at 37 °C with a human umbilical endothelial cell line. The synthesis of 6-oxo-PGF1α and endothelin 1, and NOS3 mRNA expression, were measured at each time point. VLDL from pre-eclamptic women stimulated endothelial cell 6-oxo-PGF1α synthesis to a lesser extent than that from normal pregnant women (P< 0.05). LDL from women with pre-eclampsia also stimulated 6-oxo-PGF1α synthesis to a lesser extent than LDL from normal pregnant women, but the effect was less sustained. The effect of HDL from women with pre-eclampsia on 6-oxo-PGF1α synthesis was similar to that of HDL from normal pregnant women. The pre-incubation levels of lipid peroxides in VLDL and LDL were not different between the normal pregnant and pre-eclamptic women, and cannot account for the decrease in 6-oxo-PGF1α synthesis. VLDL, LDL and HDL from women with pre-eclampsia did not affect endothelial cell synthesis of endothelin 1 or expression of NOS3 mRNA differently from lipoproteins from normal pregnant women. This study suggests that VLDL, and to a lesser extent LDL, from women with pre-eclampsia could potentially contribute to the reduced systemic 6-oxo-PGF1α synthesis observed in the pre-eclamptic syndrome.

Sign in / Sign up

Export Citation Format

Share Document