in vivo Monitoring with micro-implantable hypoxia sensor based on tissue acidosis.

Hypoxia is a common medical problem, sometimes difficult to detect and caused by different situations. Control of hypoxia is of great medical importance and early detection is essential to prevent life threatening complications. However, the few current methods are invasive, expensive, and risky.

Non-invasive monitoring of pH and oxygen using miniaturized electrochemical sensors in an animal model of acute hypoxia.

Background: One of the most prevalent causes of fetal hypoxia leading to stillbirth is placental insufficiency. Hemodynamic changes evaluated with Doppler ultrasound have been used as a surrogate marker of fetal hypoxia. However, Doppler evaluation cannot be performed continuously.

Micro-needle implantable electrochemical oxygen sensor: ex-vivo and in-vivo studies.

Oxygen is vital for energy metabolism in mammals and the variability of the concentration is considered a clinical alert for a wide range of metabolic malfunctions in medicine. In this article, we describe the development and application of a micro-needle implantable platinum-based electrochemical sensor for measuring partial pressure of oxygen in intramuscular tissue (in-vivo) and vascular blood (ex-vivo). The Pt-Nafion® sensor was characterized morphological and electrochemically showing a higher sensitivity of -2.

Enhanced detection of quantum dots labeled protein by simultaneous bismuth electrodeposition into microfluidic channel.

In this study, we propose an electrochemical immunoassay into a disposable microfluidic platform, using quantum dots (QDs) as labels and their enhanced detection using bismuth as an alternative to mercury electrodes. CdSe@ZnS QDs were used to tag human IgG as a model protein and detected through highly sensitive stripping voltammetry of the dissolved metallic component (cadmium in our case). The modification of the screen printed carbon electrodes (SPCEs) was done by a simple electrodeposition of bismuth that was previously mixed with the sample containing QDs.

Simple on-plastic/paper inkjet-printed solid-state Ag/AgCl pseudoreference electrode.

A miniaturized, disposable, and low cost Ag/AgCl pseudoreference electrode based on inkjet printing has been developed. Silver ink was printed and chlorinated with bleach solution. The reference electrodes obtained in this work showed good reproducibility and stability during at least 30 min continuous measurement and even after 30 days storage without special care.

An integrated phenol 'sensoremoval' microfluidic nanostructured platform.

Phenol is a widely used chemical that for several reasons may be released into the environment and, consequently, its detection and subsequent destruction into the ground and surface waters are of special importance. Herein, a simple lab-on-a-chip (LOC) device based on biocompatible and biodegradable CaCO3- poly(ethyleneimine) (PEI) nanostructured microparticles (MPs) to detect and remove phenolic wastes is proposed. The detection of phenol using a hybrid polydimethylsiloxane (PDMS)/glass chronoimpedimetric microchip and its removal in the same LOC system through the use of an extra CaCO3-PEI MPs microcolumn is achieved.

On-chip magneto-immunoassay for Alzheimer's biomarker electrochemical detection by using quantum dots as labels.

Electrochemical detection of cadmium-selenide/zinc-sulfide (CdSe@ZnS) quantum dots (QDs) as labeling carriers in an assay for apolipoprotein E (ApoE) detection has been evaluated. The immunocomplex was performed by using tosylactivated magnetic beads as preconcentration platform into a flexible hybrid polydimethylsiloxane (PDMS)-polycarbonate (PC) microfluidic chip with integrated screen printed electrodes (SPE). All the immunoassay was performed in chip and in flow mode.

Nanostructured CaCO₃-poly(ethyleneimine) microparticles for phenol sensing in fluidic microsystem.

A new and simple strategy based on nanostructured CaCO₃-poly(ethyleneimine) (PEI) microparticles (MPs) for phenol sensing using PDMS/glass fluidic microchip is developed. This fluidic microsystem including integrated screen-printed electrodes modified with CaCO₃-PEI MPs and tyrosinase (Tyr) through cross-linking with glutaraldehyde, represents a low-cost platform for phenol detection. The designed fluidic microsystem improves the sensitivity of the biosensor allowing the detection of very low concentrations of phenol (up to 10 nM).

On-chip electrochemical detection of CdS quantum dots using normal and multiple recycling flow through modes.

A flexible hybrid polydimethylsiloxane (PDMS)-polycarbonate (PC) microfluidic chip with integrated screen printed electrodes (SPE) was fabricated and applied for electrochemical quantum dots (QDs) detection. The developed device combines the advantages of flexible microfluidic chips, such as their low cost, the possibility to be disposable and amenable to mass production, with the advantages of electrochemistry for its facility of integration and the possibility to miniaturize the analytical device. Due to the interest in biosensing applications in general and particularly the great demand for labelling alternatives in affinity biosensors, the electrochemistry of cadmium sulfide quantum dots (CdS QDs) is evaluated.

Nanomaterials and lab-on-a-chip technologies.

Lab-on-a-chip (LOC) platforms have become important tools for sample analysis and treatment with interest for DNA, protein and cells studies or diagnostics due to benefits such as the reduced sample volume, low cost, portability and the possibility to build new analytical devices or be integrated into conventional ones. These platforms have advantages of a wide set of nanomaterials (NM) (i.e.

Fabrication of thermoplastics chips through lamination based techniques.

In this work, we propose a novel strategy for the fabrication of flexible thermoplastic microdevices entirely based on lamination processes. The same low-cost laminator apparatus can be used from master fabrication to microchannel sealing. This process is appropriate for rapid prototyping at laboratory scale, but it can also be easily upscaled to industrial manufacturing.

Evaluation of microchip material and surface treatment options for IEF of allergenic milk proteins on microchips.

The use of glass and PDMS microchips has been investigated to perform rapid and efficient separation of allergenic whey proteins by IEF. To decrease EOF and to limit protein adsorption, two coating procedures have been compared. The first one consists in immobilizing hydroxypropyl cellulose (HPC) and the second one poly(dimethylacrylamide-co-allyl glycidyl ether) (PDMA-AGE).

High-throughput simultaneous detection of point mutations and large-scale rearrangements by CE.

The detection of unknown mutations is important both in population genetics research and in diagnosis. At present, two different methods must be used to detect either point mutations or large-scale genetic rearrangements, which is costly and time-consuming. We describe here a new method for the simultaneous detection of these two types of mutations.

Lamination-based rapid prototyping of microfluidic devices using flexible thermoplastic substrates.

Transposing highly sensitive DNA separation methods (such as DNA sequencing with high read length or the detection of point mutations) to microchip format without loss of resolution requires fabrication of relatively long (approx. 10 cm) microchannels along with sharp injection bands. Conventional soft lithography methods, such as mold casting or hot-embossing in a press, are not convenient for fabricating long channels.