Potentiometric microsensors

Janata, Jiřı́

doi:10.1021/cr00103a001

Cited by 87 publications

(51 citation statements)

References 12 publications

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“…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%

“…They required longer equilibration (conditioning) time [67,88] and were characterized by drifting potentials and modest repeatibility. The majority of the problems experienced with these "all solid-state" microelectrodes were related to the mismatch ("blocked" interfaces) between ion-conducting (IS membrane) and electronically conducting phases (substrate electrode) in which the charge carriers cannot pass from one phase into the other [86].…”

Section: Planar Microfabricated Electrodesmentioning

confidence: 99%

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

Lindner¹,

Umezawa

2008

Pure and Applied Chemistry

231

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of new discoveries and experimental possibilities in the field of ISEs, some of the IUPAC recommendations have become outdated.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%

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

231

168

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“…The usual potentiometric approach utilises the glass electrode [2,3] due to its simplicity of handling and low sensitivity to many potential interferents within the solution to be measured. Other devices include ion-selective membranes [4,5], ion-selective field effect transistors [3,6], two-terminal microsensors [7] as well as optical [8] and conductometric [9] pH-sensing devices. However, these types of devices can often suffer from instability and/or drift and therefore require constant recalibration [10].…”

Section: Introductionmentioning

confidence: 99%

Anthraquinone-derivatised carbon powder: reagentless voltammetric pH electrodes

Wildgoose

2003

Talanta

100

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“…Biomedical sensors can be manufactured using many different technologies (21,22 The primary limitation of thin-film microfabrication for sensors is that the design and capital equipment costs are very high, although per-unit costs may be relatively low. By comparison, the thick-film technique is relatively inexpensive; however, the quality of the deposited film is lower.…”

Section: Thin-and Thick-film Fabricationmentioning

confidence: 99%

“…Microfabricated potentiometric sensors are planar versions of the conventional macroelectrodes, reducing in size the typical three-dimensional electrode structures into two-dimensional, multilayer arrangements ( Figure 6). The first devices were based on field-effect rather than microFaradic principles (21,24), using membranes cast on solid surfaces-Si/SiO 2 with no intervening internal electrolyte solution. These devices introduced analytical chemists to thin-film microfabrication technologies-photolithographic reduction, thin-film metalization, chemical etching, spin coating, and positive and negative photoresists.…”

Section: Thin-and Thick-film Fabricationmentioning

confidence: 99%

Microfabricated Potentiometric Electrodes and Their In Vivo Applications.

Lindner

Buck²

2000

Anal. Chem.

107

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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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Potentiometric microsensors

Cited by 87 publications

References 12 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)

Anthraquinone-derivatised carbon powder: reagentless voltammetric pH electrodes

Microfabricated Potentiometric Electrodes and Their In Vivo Applications.

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