Conceptions, materials, processing technologies and fields of application for miniaturized electrochemical sensors with planar membranes

Vonau, Winfried; Enseleit, U.; Gerlach, Frank; Herrmann, Susan Strange

doi:10.1016/j.electacta.2004.02.048

Cited by 18 publications

(10 citation statements)

References 9 publications

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“…Reactive sputtering of platinum metal targets in argon-oxygen atmospheres is used to produce 1 μm thick oxide electrodes on alumina and silicon substrates; palladium and platinum oxides were found to be less stable than ruthenium oxide [ 58 ]. An overview of applications [ 59 ] is given in Table 5 . Both potentiometric and amperometric sensors [ 60 ] have been used.…”

Section: Platinum Metal Oxide Probes In Aqueous Solutionsmentioning

confidence: 99%

Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook

Kurzweil¹

2009

Sensors

190

104

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Novel applications of online pH determinations at temperatures from -35 °C to 130 °C in technical and biological media, which are all but ideal aqueous solutions, require new approaches to pH monitoring. The glass electrode, introduced nearly hundred years ago, and chemical sensors based on field effect transistors (ISFET) show specific drawbacks with respect to handling and long-time stability. Proton sensitive metal oxides seem to be a promising and alternative to the state-of-the-art measuring methods, and might overcome some problems of classical hydrogen electrodes and reference electrodes.

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Section: Platinum Metal Oxide Probes In Aqueous Solutionsmentioning

confidence: 99%

Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook

Kurzweil¹

2009

Sensors

190

104

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“…potentiometric, amperometric, impedimetric, etc.). In this way a planar electrochemical multi-sensor array was developed [48] for simultaneous determination of dissolved ions such as chloride, dissolved oxygen and electrical conductivity in biological liquids. A disposable allsolid-state planar-type potentiometric electronic tongue has been developed with a five-sensor array screen-printed on a polymeric substrate [49].…”

Section: Integrated Sensor Arraysmentioning

confidence: 99%

Recent trends in potentiometric sensor arrays—A review

Bratov

Abramova

Ipatov

2010

Analytica Chimica Acta

223

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“…The solid-state reference electrode (SSRE) has been important to alleviate the problems of liquid-type RE in mass-production, maintenance, contamination by internal solution, and miniaturization. A lot of efforts have been made in this respect, for example, Ag|AgCl with a protective membrane or ionic liquid maintaining chloride concentration [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and ionsensitive field-effect transistors (ISFET) covered by pH-buffered gel 16 or pH-insensitive membrane. [17][18][19][20] Especially, Ag|AgCl has been widely adopted for the realization of miniaturized and micro-machined planar REs, 21 for example, Ag|AgCl coated with electrolyte immobilized and protected with Nafion or polyurethane, 1 Ag|AgCl based on aromatic polyurethane incorporating both cation-and anion-exchange sites, 2 Ag|AgCl based on hydrophobic ionic liquid saturated with Ag|AgCl, 3 Ag|AgCl with KCl paste as chloride reservoir, [4][5][6][7] Ag|AgCl coated with silicon rubber containing KCl, Nafion, and ion-selective polyurethane, 8 Ag|AgCl coated with polystyrene having quaternary ammonium chloride, 9 Ag|AgCl with polymeric junction membrane allowing quick hydration of KCl containing hydrogel, 10 Ag|AgCl covered by conducting polymer such as polypyrrole or poly (3,4-ethylenedioxythiophene), 11 Ag|AgCl modified with agar gel inner electrolyte as liquid junction, 12 Ag|AgCl miniaturized in smart card with KCl-epoxy resin, 13 and Ag|AgCl with solid crystalline KCl melt.…”

Section: Introductionmentioning

confidence: 99%

Nanoporous platinum solid-state reference electrode with layer-by-layer polyelectrolyte junction for pH sensing chip

Noh

Park²,

Boo³

et al. 2011

Lab Chip

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A novel solid-state reference electrode was developed by combining nanoporous Pt with polyelectrolyte junction. The polyelectrolyte junction was formed in the microchannel connecting the nanoporous Pt and the sample solution, and had layer-by-layer structure of oppositely charged polyelectrolytes. The layer-by-layer polyelectrolyte junction effectively blocked the mass transport of ions and maintains constant pH environments on the surface of the nanoporous Pt. The assembly of the polyelectrolyte junction and the nanoporous Pt, which produced reportedly a stable open-circuit potential in response to constant pH, exhibited outstanding performance as a solid-state reference electrode (e.g., excellent reproducibility of ±4 mV (n = 5), good long term stability of ±1 mV (for 50 h), and independence of solution environments like pH and ionic strength). A working principle of the solid-state reference electrode with layer-by-layer polyelectrolyte junction was suggested in terms of the roles of each layer and the effect of the neighboring layer. As a demonstrative application of the solid-state reference electrode, a miniaturized chip-type solid-state pH sensor comprised of two nanoporous Pt electrodes and a micro-patterned layer-by-layer polyelectrolyte junction was developed. The solid-state pH sensing chip showed reliable pH responses without liquid junction and successfully worked in a variety of buffers, beverages, and biological samples, showing its potential utility for practical applications. In addition, the solid-state pH sensing chip was integrated in a microfluidic system to be utilized for pH monitoring in microfluidic flow.

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Conceptions, materials, processing technologies and fields of application for miniaturized electrochemical sensors with planar membranes

Cited by 18 publications

References 9 publications

Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook

Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook

Recent trends in potentiometric sensor arrays—A review

Nanoporous platinum solid-state reference electrode with layer-by-layer polyelectrolyte junction for pH sensing chip

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