Highly Sensitive Electrochemical BioMEMS for TNF-α Detection in Humansaliva: Heart Failure

Abstract Prediction of disease progression using saliva as a diagnostic medium has roused the interest of scientific researchers in the 10 last past years. Potentially important biomarkers are increased in saliva during local and systemic inflammation. In the present study we have developed a highly sensitive biosensor for TNF-α detection in human saliva of patients suffering from heart failure. Therefore, a fully integrated electrochemical BioMEMS was developed in order to increase the sensitivity of detection, decrease the time of analysis, and to simultaneously detect varying cytokine biomarkers using eight gold working microelectrodes (WE). The monoclonal antibodies (mAb) anti-human Tumor Necrosis Factor alpha (anti-TNF-α) were immobilized onto gold microelectrodes through functionalization with carboxyl diazonium. Cyclic voltammetry (CV) was applied during the microelectrode functionalization process to characterize the gold microelectrode surface properties. Finally, electrochemical impedance spectroscopy (EIS) characterized the modified gold microelectrodes, and the detection range of TNF-α cytokines was from 1pg/mL to 15 pg/mL

Understanding graphic narrative through the synthesis of comic and picturebooks

This study was undertaken to develop a better understanding of comics, picturebooks, and their relationship through progressive attempts to combine them in practice. The study was motivated by an interest in hybrid forms as a site where narrative techniques from different forms are put to alternative use in a new context. The research contributes to current scholarly discussion of graphic narrative from a practitioner’s perspective. Reflective practice offers unique potential as a method for critical study. Comparative analysis of changes over time throws light on each form’s typical mechanisms for graphic storytelling, and demonstrates their function in different contexts. Problems arising in practice are catalysts for a process of dynamic, analogical theory-formation and -testing, which often challenges or supplements existing knowledge, leading to a more nuanced understanding of the forms with which practice engages. Findings evolved, firstly, from the insight that conventions for graphic storytelling function differently depending on the mode of reading and the formal context. Secondly, the degree to which the practitioner is constrained by formal limitations was found to demand a disciplined distillation of content that deliberately creates space for different kinds of readerly engagement. The study concluded that, due to their adaptation towards solitary reading, comics exert greater control over their readers, whereas picturebooks tend to be more flexible in order to accommodate different modes of reading. The way readers engage with a work impacts on the function of conventions and techniques for graphic storytelling as much as a change in formal context. Moreover, the discipline of the picturebook form demands greater economy, which can create more space for reader participation. However, neither distinct modes of reading nor differing degrees of constraint constitute grounds for definitive distinction between comics and picturebooks: instead, they offer alternative frameworks for the critical consideration of graphic narratives

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A flexible electrochemical micro lab-on-chip: application to the detection of interleukin-10

International audienceWe report on a simple method to manufacture an electrochemical micro lab-on-chip (mu LoC), for the detection of interleukin-10 (IL-10) cytokine of patients suffering from heart failure (HF). To monitor the critical levels of inflammation, a mu LoC containing eight gold microelectrodes based on a polyimide (PI) substrate was fabricated. The microelectrodes were manufactured on PI by a combination of soft lithographical tools. To produce an operational mu LoC, a microfluidic system fabricated in polydimethylsiloxane was sealed onto the PI substrate through silane reagent (3-aminopropyl) triethoxysilane. Cyclic voltammetry was applied as the characterization technique for the gold microelectrode surface properties. Finally, electrochemical characterization of the mu LoC was determined by electrochemical impedance spectroscopy for the quantification of IL-10. These were detected within the range of 1-15 pg. mL(-1). The time and cost of fabrication for this mu LoC was very low when compared to those that have been fabricated by conventional lithography

A fully integrated electrochemical biosensor platform fabrication process for cytokines detection

International audienceInterleuldn-1b (IL-1b) and interleukin-10 (IL-10) biomarkers are one of many antigens that are secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). In the present study, we have developed a fully integrated electrochemical biosensor platform for cytokine detection at minute concentrations. Using eight gold working microelectrodes (WEs) the design will increase the sensitivity of detection, decrease the time of measurements, and allow a simultaneous detection of varying cytokine biomarkers. The biosensor platform was fabricated onto silicon substrates using silicon technology. Monoclonal antibodies (mAb) of anti-human IL-lb and anti-human IL-10 were electroaddressed onto the gold WEs through functionalization with 4-carboxymethyl aryl diazonium (CMA). Cyclic voltammetry (CV) was applied during the WE functionalization process to characterize the gold WE surface properties. Finally, electrochemical impedance spectroscopy (EIS) characterized the modified gold WE. The biosensor platform was highly sensitive to the corresponding cytokines and no interference with other cytokines was observed. Both cytokines: IL-10 and IL-lb were detected within the range of 1 pg mL(-1) to 15 pg mL(-1). The present electrochemical biosensor platform is very promising for multi-detection of biomolecules which can dramatically decrease the time of analysis. This can provide data to clinicians and doctors concerning cytokines secretion at minute concentrations and the prediction of the first signs of inflammation after LVAD implantation

Novel nanostructured indium tin oxide electrode for electrochemical immunosensors: Suitability for the detection of TNF-α

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Development of biosensors for non-invasive measurements of heart failure biomarkers in saliva

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A low-cost and miniaturized potentiostat for the monitoring of immunobiosensors by electrochemical impedance spectroscopy

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Silicon Nitride Capacitive Chemical Sensor for Phosphate Ion Detection Based on Copper Phthalocyanine - Acrylate-polymer

International audienceIn this work, we report the development of a highly sensitive capacitance chemical sensor based on a copper C, C, C, C-tetra-carboxylic phthalocyanine-acrylate polymer adduct (Cu(II) TCPc-PAA) for phosphate ions detection. A capacitance silicon nitride substrate based Al-Cu/Si-p/SiO2/Si3N4 structure was used as transducer. These materials have provided good stability of electrochemical measurements. The functionalized silicon-based transducers with a Cu(II) Pc-PAA membrane were characterized by using Mott-Schottky technique measurements at different frequency ranges and for different phosphate concentrations. The morphological surface of the Cu(II) Pc-PAA modified silicon-nitride based transducer was characterized by contact angle measurements and atomic force microscopy. The pH effect was also investigated by the Mott-Schottcky technique for different Tris-HCl buffer solutions. The sensitivity of silicon nitride was studied at different pH of Tris-HCl buffer solutions. This pH test has provided a sensitivity value of 51 mV/decade. The developed chemical sensor showed a good performance for phosphate ions detection within the range of 10(-10) to 10(-5) M with a Nernstian sensitivity of 27.7 mV/decade. The limit of detection of phosphate ions was determined at 1 nM. This chemical sensor was highly specific for phosphate ions when compared to other interfering ions as chloride, sulfate, carbonate and perchlorate. The present capacitive chemical sensor is thus very promising for sensitive and rapid detection of phosphate in environmental applications

Capacitance Polypyrrole‐based Impedimetric Immunosensor for Interleukin‐10 Cytokine Detection

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