Voltammetric measurements of reversible and quasi-reversible redox species using carbon film based interdigitated array microelectrodes

Niwa, Osamu; Tabei, Hisao

doi:10.1021/ac00074a016

Cited by 100 publications

(62 citation statements)

References 35 publications

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“…39,40 A silicone-based positive photoresist was then spin-coated on the carbon film. The electrode pattern was exposed with a PLA-5000 mask aligner (Canon, Tokyo) developed in an alkaline solution, rinsed in deionized water and dried.…”

Section: Sensor Fabricationmentioning

confidence: 99%

Microfabricated On-Line Sensor for Continuous Monitoring of l-Glutamate

Niwa

Horiuchi

Kurita³

et al. 1998

ANAL. SCI.

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Various methods have been developed for measuring the in vivo and in vitro concentrations of L-glutamate, since glutamate plays an important role in synaptic efficacy, including the long-term potentiation (LTP) 1,2 and long-term depression (LTD) 3,4 of excitatory neurotransmission. It is also reported to be a factor in several diseases including ischemia and nerve cell death.5,6 A number of methods have already been proposed for measuring L-glutamate, including chromatographic technique 7 and capillary electrophoresis. 8,9 However, these methods require time for derivatization and column separation.Recently, many groups have been focusing on the development of amperometric enzyme sensors using glutamate dehydrogenase and glutamate oxidase. The latter enzyme has more often been used to fabricate glutamate sensors because a glutamate dehydrogenase sensor requires the addition of NAD + . 10-12 Therefore, glutamate oxidase has been more often used to fabricate electrochemical sensors for detecting the neurotransmitter, L-glutamate. [13][14][15][16][17][18][19][20][21][22][23][24] Carbon fiber or metal wire microelectrodes modified with glutamate oxidase have been employed for measuring L-glutamate in the brain and in cultured rat brain tissue. [13][14][15][16] It has been reported that L-glutamate increases as the result of KCl and electrical stimulations. The advantages of the enzyme-modifed electrodes are their fast response and their ability to measure a small localized area.By contrast, on-line L-glutamate sensors have been developed. These consist of a syringe pump, a microdialysis (MD) sampling probe, an enzymatic reactor and an electrode in a flow cell. [17][18][19][20][21][22] On-line sensors are particularly useful for measuring in vivo L-glutamate, since they are very stable. This is because the flow measurement is very reproducibile and the MD membrane eliminates high molecular weight interferents such as proteins. The reported detection limits of online L-glutamate sensors are from 10 nM to 0.5 µM, which are lower than those of microelectrode-based sensors. However, the on-line sensor response is slower than that of the microelectrode sensors and it has a large sampling probe (usually 1 -3 mm long and a few hundred µm in diameter). There have been a few reports on the use of on-line sensors for measuring cultured nerve cells. However, their slow response and large sampling probe size limits their spatial and temporal resolutions in spite of their high sensitivity and long term stability. 21,22 We reported an on-line L-glutamate sensor for measuring dissociated nerve cell cultures. 23 The sensor consists of a glass capillary for sampling combined with an electrochemical thin layer flow cell. Since the sampling probe is much smaller than the MD probe, we can achieve better spatial resolution. We observed the transient release of L-glutamate by stimulating the inhibitory neurotransmitter, γ-aminobutyric acid (GABA), using this sensor. 24 However, the relatively large volume of the sensor means that there ...

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Section: Sensor Fabricationmentioning

confidence: 99%

Microfabricated On-Line Sensor for Continuous Monitoring of l-Glutamate

Niwa

Horiuchi

Kurita³

et al. 1998

ANAL. SCI.

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“…They make use of EC reactions or the surface property changes upon target binding. Advances in microfabrication technology have provided electrode configurations such as microelectrode arrays [3] and interdigitated arrays (IDA) [4], but their performance can be further enhanced by miniaturizing to nanoscale. Recent progress in nanofabrication technologies like electronbeam lithography and nanoimprinting enable fabrication of 1-D nanostructure electrodes like carbon nanofibers [5]- [7], carbon nanotube bundles [8], [9], nanoscale IDA [10], silicon nanowires [11], and diamond nanowires [12], which are capable of high spatial and temporal resolutions, possibly yielding sufficient sensitivity to single molecule detection.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Vertically Aligned Carbon Nanofibers Without Electrochemical Treatment Using Atomic Force Microscopy

Dong

Wejinya

2011

IEEE Trans. Nanotechnology

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One of the major limitations in the development of ultrasensitive electrochemical biosensors based on 1-D nanostructure is the difficulty involved with reliably fabricating nanoelectrode arrays. In the previous work (Arumugam et al., 2009), a simple, robust, and scalable wafer-scale fabrication method to produce multiplexed biosensors was introduced. Each sensor chip consists of nine individually addressable arrays that uses electron-beam patterned vertically aligned carbon nanofibers (VACNFs) as the sensing element. To ensure nanoelectrode behavior with higher sensitivity, VACNFs were precisely grown on 100 nm Ni dots with 1 μm spacing on each micropad. However, in order to examine the quality and measure the height and diameter of the VACNFs, some surface detection and measurement tool at the nanoscale level is needed. In this paper, we introduce an approach to measure these nanoscale features through atomic force microscope. With this method, both the 2-D and 3-D images of sample surface are generated and the sizes of carbon nanofibers and cavities are obtained. Furthermore, statistical analysis is carried out to enable the improvement of VACNFs' growth and fabrication.

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“…The detection limit of this electrode was 200 pM for AD. Alternatively, a microfabricated interdigitated array (IDA) electrode has been used for electrochemical redox cycling [15,16]. The carbon-based IDA electrode exhibited a low detection limit of 6 pM when it was combined with an HPLC system [17].…”

Section: Introductionmentioning

confidence: 99%