Publications by authors named "Sayed A M Marzouk"

This paper describes an experimental system for simultaneous permeation of a pressurized test gas through different gas permeable membranes and provides a proof of concept for a novel approach for gas identification/fingerprinting for potential construction of electronic noses. The design, construction, and use of a six-channel system which allows simultaneous gas permeation from a single pressurized gas compartment through six different parallel membranes are presented. The permeated gas is accumulated in confined spaces behind the respective membranes.

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Article Synopsis
  • The paper discusses the design and fabrication of three innovative electrochemical measurement cells using screen-printed electrode chips (SPECs), highlighting their specific applications in flow injection, thin-layer, and batch techniques.
  • Each cell has unique features, including an acrylic base and cover, ensuring easy electrical connections, containment of the SPEC to prevent damage, compatibility with various SPECs, and excellent sealing, with the flow cell allowing for customization and visual inspection.
  • The thin-layer cell enables near-ideal voltammetry, while the versatile universal batch cell caters to a wide range of sample volumes and conditions, also providing novel methods for advanced electrochemical analysis.
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A novel polymeric membrane sensor sensitive to (4-sulphophenylazo-)1-naphthylamine (SPAN) based on the use of tris(bathophenanthroline) Ni(II)-SPAN ion pair as an ion exchanger in plasticised PVC membrane is described. The sensor exhibits a linear calibration plot with near-Nernstian anionic slope of -55.0+/-0.

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This paper describes the first report on the development, characterization, and applications of a prototype amperometric biosensor for free sialic acid (SA). The sensor was constructed by the coimmobilization of two enzymes, i.e.

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Preparation, characterization, and applications of a 1,10-phenanthrolinium cation (phenH(+))-sensitive potentiometric sensor are described. The sensor incorporates a liquid polymeric membrane consisting of phenH-tetraphenylborate, nitrophenyloctyl ether, and poly(vinyl chloride) as ion exchanger, plasticizer, and polymeric support, respectively. The sensor exhibits a fast and Nernstian response to phenH(+) over the concentration range of 6 x 10(-6)-2 x 10(-4) M with a monovalent cationic slope of 58.

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In the present paper, the preparation and characterization of an improved solid-state pH sensor are described. The sensor is based on anodically electrodeposited iridium oxide film, as a pH-sensing layer. Merits of the present sensor include (i) excellent adhesion of the pH sensitive layer to the substrate, (ii) excellent reproducibility of sensor fabrication, (iii) faster preparation procedure, and (iv) low cost of the titanium substrate.

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Simultaneous and continuous measurements of extracellular pH, potassium (K(+)), and lactate (L(-)) in ischemic rabbit papillary muscle are presented for the first time. Potentiometric pH and K(+) sensors and an amperometric lactate biosensor were used. These miniature electrodes were previously developed and individually tested for this purpose.

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