In vivo and in vitro testing of microelectronically fabricated planar sensors designed for applications in cardiology

Lindner, Ernő; Coşofreţ, Vasile V.; Ufer, Stefan; Johnson, Timothy A.; Ash, R. Bruce; Nagle, H. Troy; Neuman, Michael R.; Buck, Richard P.

doi:10.1007/bf00321250

Cited by 53 publications

(31 citation statements)

References 6 publications

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“…1a) with a hydrogel-based electrolyte (Fig. 1c) [56]. Hydrogel-contact ISEs have been designed for demanding applications in such diverse areas as cardiology [56,57], point-of-need diagnosis of cystic fibrosis [58] and in situ analysis on the planet Mars [59].…”

Section: Solid-state Isesmentioning

confidence: 99%

Conducting Polymer‐Based Solid‐State Ion‐Selective Electrodes

2006

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Conducting polymers, i.e., electroactive conjugated polymers, are useful both as ion-to-electron transducers and as sensing membranes in solid-state ion-selective electrodes. Recent achievements over the last few years have resulted in significant improvements of the analytical performance of solid-contact ion-selective electrodes (solid-contact ISEs) based on conducting polymers as ion-to-electron transducer combined with polymeric ion-selective membranes. A significant amount of research has also been devoted to solid-state ISEs based on conducting polymers as the sensing membrane. This review gives a brief summary of the progress in the area in recent years.

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Section: Solid-state Isesmentioning

confidence: 99%

Conducting Polymer‐Based Solid‐State Ion‐Selective Electrodes

2006

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“…Due to their low cost and small size, microfabricated ISEs are often aimed for the measurements of a few microliters of samples (e.g., whole blood, serum, plasma, urine, or saliva) in single-use cartridges [13]. They have also been tested for short-term in vivo measurements or closed-loop monitoring of ion activities in biological samples [14,87,88].…”

Section: Planar Microfabricated Electrodesmentioning

confidence: 99%

“…and patterning multiple membrane layers over solid surfaces. The technology for these so-called "all solid-state" electrodes projected numerous advantages in design (smaller sizes, thus smaller sample volumes), sensor handling (maintenance free), and applications (long-term in vivo monitoring) [14,86,87]. Due to their low cost and small size, microfabricated ISEs are often aimed for the measurements of a few microliters of samples (e.g., whole blood, serum, plasma, urine, or saliva) in single-use cartridges [13].…”

Section: Planar Microfabricated Electrodesmentioning

confidence: 99%

Performance evaluation criteria for preparation and measurement of macro- and microfabricated ion-selective electrodes (IUPAC Technical Report)

Lindner¹,

Umezawa

2008

Pure and Applied Chemistry

234

168

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Over the last 30 years, IUPAC published several documents with the goal of achieving standardized nomenclature and methodology for potentiometric ion-selective electrodes (ISEs). The ISE vocabulary was formulated, measurement protocols were suggested, and the selectivity coefficients were compiled. However, in light of new discoveries and experimental possibilities in the field of ISEs, some of the IUPAC recommendations have become outdated. The goal of this technical report is to direct attention to ISE practices and the striking need for updated or refined IUPAC recommendations which are consistent with the state of the art of using macro- and microfabricated planar microelectrodes. Some of these ISE practices have never been addressed by IUPAC but have gained importance with the technological and theoretical developments of recent years. In spite of its recognized importance, a generally acceptable revision of the current IUPAC recommendations is far beyond the scope of this work.

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“…tional groups, such as carboxylated, aminated, and hydroxylated PVC, are used (31,(39)(40)(41). Membranes with no plasticizer (silicone rubber) or decreased amounts of plasticizer (aliphatic polyurethanes) proved to have better adhesive properties in peel-off tests.…”

Section: Water and Gas Transport Effectsmentioning

confidence: 99%

“…Good adhesion is even more critical for tissue measurements so that sensors can withstand cardiovascular motion (39). To increase the adhesive strength, modified PVC membranes with various func- tional groups, such as carboxylated, aminated, and hydroxylated PVC, are used (31,(39)(40)(41). Membranes with no plasticizer (silicone rubber) or decreased amounts of plasticizer (aliphatic polyurethanes) proved to have better adhesive properties in peel-off tests.…”

mentioning

confidence: 99%

Microfabricated Potentiometric Electrodes and Their In Vivo Applications.

Lindner

Buck²

2000

Anal. Chem.

Self Cite

110

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New technologies are yielding mass-produced, miniature, ion-selective electrodes that can be routinely used in biology E = (ε 1 + ε 2 + ε 3 + ε 4 + ε 5 ) + ε j + (ε´+ ε´´) = E o + ε j + ε M (1) in which E o is a constant potential term comprising the potential contributions ε 1 to ε 5 , which arise within the system from the two reference electrodes in the cell; ε j is the liquid junction potential; and ε M is the membrane potential. We usually seek electrolyte combinations for the reference electrode in which ε j is nearly zero. The essential part of an ISE is the ion-sensitive membrane that is commonly placed between two aqueous phases-for example, the sample and the inner electrolyte solution. Ion-selective membranes made from glass, single crystals (e.g., LaF 3 ), pressed pellets of insoluble precipitates (e.g., AgCl, AgBr, AgI), or solvent polymeric membranes (highly plasticized polymeric films, also known as liquid membranes) are widely used in analytical practice. In this article, we will focus our discussions on microfabricated ISEs based on solvent polymeric or liquid membranes.Typically, the membrane potential is divided into three separate potential contributions-the phase boundary potentials at both interfaces (ε´and ε´´) and the diffusion potential within the ion-selective membrane (3-5). However, the membrane's internal diffusion potential is zero if there are no concentration gradients within the membrane. The basic equation for the interfacial potentials εá nd ε´´is in which R is the gas constant, T is the absolute temperature, F is the Faraday constant, z i is the charge number of the primary ion i, k i is the single-ion partition coefficient, and a i and ā i are the primary ion solution and membrane activities, respectively. The phase boundary potential is a simple function of the sample ion activities only when ā i is not influenced significantly by the sample. Accordingly, for an ideally selective membrane, the membrane potential is directly related to the respective activities in the contacting solutions in which a i (1) and a i (2) are the ion activities in the sample and the inner filling solution, respectively. A Nernstian response is expected in a potentiometric cell when the liquid junction potential can be neglected and the inner filling solution of the electrode is kept constant:Most of the microfabricated ion sensors are based on solvent polymeric or liquid membranes. Overplasticized poly(vinyl chloride) (PVC) is most frequently used as the membrane matrix. The selectivity of these membranes is determined by the dielectric properties of the plasticizer and the selective, hydrophobic complexing agents, which are neutral or charged carriers (ionophores), within the membrane phase. A comprehensive review of the carrier-based ISEs and bulk optodes was published recently (6, 7).Calibrating ISEs by serial dilution gives a plot of the cell voltage as a function of the logarithm of the primary ion activity, as shown in Figure 2. It is linear over a wide concentration range (generally from...

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In vivo and in vitro testing of microelectronically fabricated planar sensors designed for applications in cardiology

Cited by 53 publications

References 6 publications

Conducting Polymer‐Based Solid‐State Ion‐Selective Electrodes

Conducting Polymer‐Based Solid‐State Ion‐Selective Electrodes

Performance evaluation criteria for preparation and measurement of macro- and microfabricated ion-selective electrodes (IUPAC Technical Report)

Microfabricated Potentiometric Electrodes and Their In Vivo Applications.

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