A Sandwich Enzyme Electrode Giving Electrochemical Scavenging of Interferents

Bacon, Nicola C.; Hall, Elizabeth A. H.

doi:10.1002/(sici)1521-4109(199907)11:10/11<749::aid-elan749>3.0.co;2-g

Cited by 11 publications

(5 citation statements)

References 26 publications

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“…Electrochemically removing the interfering species before they can reach the transducing electrode is an approach which has received attention of late. Bacon and Hall fabricated an enzyme electrode in which the enzyme layer was sandwiched between an underlying platinum detector electrode and an overlying permeable grid electrode. The interfering species were oxidized at this permeable electrode (effectively acting as an electrolysis prereactor) while the analyte passed through the guard electrode and reacted with the enzyme.…”

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confidence: 99%

Solution to the Problem of Interferences in Electrochemical Sensors Using the Fill-and-Flow Channel Biosensor

2002

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A generic fill-and-flow channel biosensor with upstream electrodes to determine the extent of interferences in the sample is described. A pair of upstream electrodes poised at a suitable potential allows both the calculation of the extent of removal of interfering agents and the effect of interfering agents at the detector electrode. A model was developed and tested that predicts the concentrations of all species throughout the channel and, hence, the current at each electrode due to each species. This enables correction of the detector electrode current and a more accurate determination of the analyte concentration. The concept was applied to a biosensor for the determination of glucose in the presence of ascorbic acid, acetamidophenol, and uric acid, as well as glucose in wine samples containing polyphenolic interfering agents.

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confidence: 99%

Solution to the Problem of Interferences in Electrochemical Sensors Using the Fill-and-Flow Channel Biosensor

2002

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“…The electroreduction process for O 2 can be used to measure oxygen concentration such as in the Clark O 2 electrode, or deployed for scavenging the interfering dissolved oxygen in biosensors, demonstrated by Hahn et al (1982 ; Bacon and Hall, 1999 ). It is investigated here as a method to induce local hypoxia.…”

Section: Resultsmentioning

confidence: 99%

Electrochemically induced in vitro focal hypoxia in human neurons

Wong

Varga²,

Káradóttir³

et al. 2022

Front. Cell Dev. Biol.

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Focalised hypoxia is widely prevalent in diseases such as stroke, cardiac arrest, and dementia. While in some cases hypoxia improves cellular functions, it mostly induces or exacerbates pathological changes. The lack of methodologies that can simulate focal acute hypoxia, in either animal or cell culture, impedes our understanding of the cellular consequences of hypoxia. To address this gap, an electrochemical localised oxygen scavenging system (eLOS), is reported, providing an innovative platform for spatiotemporal in vitro hypoxia modulation. The electrochemical system is modelled showing O2 flux patterns and localised O2 scavenging and hypoxia regions, as a function of distance from the electrode and surrounding flux barriers, allowing an effective focal hypoxia tool to be designed for in vitro cell culture study. O2 concentration is reduced in an electrochemically defined targeted area from normoxia to hypoxia in about 6 min depending on the O2-flux boundaries. As a result, a cell culture-well was designed, where localised O2 scavenging could be induced. The impact of localised hypoxia was demonstrated on human neural progenitor cells (hNPCs) and it was shown that miniature focal hypoxic insults can be induced, that evoke time-dependent HIF-1α transcription factor accumulation. This transcription is “patterned” across the culture according to the electrochemically induced spatiotemporal hypoxia gradient. A basic lacunar infarct model was also developed through the application of eLOS in a purpose designed microfluidic device. Miniature focal hypoxic insults were induced in cellular processes of fully oxygenated cell bodies, such as the axons of human cortical neurons. The results demonstrate experimentally that localised axonal hypoxic stress can lead to significant increase of neuronal death, despite the neurons remaining at normoxia. This suggests that focal hypoxic insult to axons alone is sufficient to impact surrounding neurons and may provide an in vitro model to study the impact of microinfarcts occurring in the deep cerebral white matter, as well as providing a promising tool for wider understanding of acute hypoxic insults with potential to uncover its pathophysiology in multiple diseases.

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“…In several cases, an accurate measurement of the concentration of L-lactic acid needs a sensitive and selective enzyme electrode, mainly in a complex matrix with low level of lactic acid. Indeed, the determination of low concentrations in complex matrix can be affected by various interfering species that could contribute directly or indirectly to the amperometric response [3]. For example, food products based on fruits or vegetables can be typical complex matrix that contains a low amount of Llactic acid compared to one of the interfering species such as ascorbic acid (AA).…”

Section: Introductionmentioning

confidence: 99%