Microfabricated Sensor Arrays Sensitive to pH and K+ for Ionic Distribution Measurements in the Beating Heart

Coşofreţ, Vasile V.; Erdősy, Miklós; Johnson, Timothy A.; Buck, Richard P.; Ash, R. Bruce; Neuman, Michael R.

doi:10.1021/ac00106a001

Cited by 142 publications

(73 citation statements)

References 29 publications

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“…Although the incorporation of "liquid reservoirs" into a sensor structure using thin film microfabrication technologies is difficult, planar potassium and hydrogen ISEs fabricated [14,88] with these hydrogel layers provided potential stabilities in the order of 0.1 mV/h and were used successfully for in vivo monitoring of ion concentration changes [91]. Unfortunately, the benefits of these hydrogel film-based sensors quickly faded away with decreasing sensor sizes (hydrogel volumes).…”

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of new discoveries and experimental possibilities in the field of ISEs, some of the IUPAC recommendations have become outdated.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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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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“…For example, they demonstrate steady state currents, higher sensitivity caused by the increased mass transport and application to highly resistant solutions. Additionally, UMEs have been applied as sensors in various techniques such as flow injection analysis [12,13], cardiovascular monitoring and organic compounds analysis [14][15][16]. For this work, we used the highly developed version of a classical cyclic voltammetric technique combined with fast Fourier transformation method (the computer program is more advanced in the algorithm for integration and filtering).…”

Section: Scheme 1 Chemical Structure Of Capmentioning

confidence: 99%

Fast Fourier transformation with continuous cyclic voltammetry at an Au microelectrode for the determination of morphine in a flow injection system

Norouzi

Ganjali

Moosavi-Movahedi

et al. 2007

Talanta

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Fast Fourier transformation with continuous cyclic voltammetry (FFTCV) in a flowing solution was applied as a detection system for the prompt Chloramphenicol (CAP) monitoring. In this method, the potential waveform consisted of two potential sections for cleaning of the electrode surface, accumulating CAP and potential ramp, which was continuously applied on a Pt-Au dual disk microelectrodes. The effects of various parameters on the sensitivity of the method were investigated. When the optimum conditions were imposed, this is a scan rate value of 70 V/s, an accumulation time of 500 ms, an accumulation potential of -300 mV and a pH value of 2. The method proved to be linear over the concentration range of 8.0 ×10 -9 -2.0 ×10 -5 mol/L (r = 0.9981) with a detection limit and a quantitation limit of 2.0 ×10 -9 and 6.6×10 -9 mol/L, respectively. Consequently, the method illustrates the requisite accuracy, sensitivity, precision and selectivity to assay CAP in its biological fluids. The proposed method has some advantages over other reported methods such as, no need for the removal of oxygen from the test solution, a sub-nanomolar detection limit, and finally the method is fast enough for the determination of any such compound, in a wide variety of chromatographic methods. As a result, FFTCV illustrates the benefits of precision, determination speed, cost-effectiveness, accuracy and simplicity, in comparison with formerly reported techniques.

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“…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.…”

Section: Water and Gas Transport Effectsmentioning

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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Microfabricated Sensor Arrays Sensitive to pH and K+ for Ionic Distribution Measurements in the Beating Heart

Cited by 142 publications

References 29 publications

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

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

Fast Fourier transformation with continuous cyclic voltammetry at an Au microelectrode for the determination of morphine in a flow injection system

Microfabricated Potentiometric Electrodes and Their In Vivo Applications.

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