Technological Barriers in the Use of Electrochemical Microsensors and Microbiosensors for in vivo Analysis of Neurological Relevant Substances

Bucur, Bogdan

doi:10.2174/157015912803217350

Cited by 12 publications

(11 citation statements)

References 94 publications

(114 reference statements)

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“…Keddie and Rohman noted that differences between the calibration solution and in vivo test environment most assuredly cause the probe to function “differently” . The main differences between in vivo and in vitro calibrations are: the mass transport through a standard solution is different due to diffusion and convection, there are numerous interferences from a complex sample matrix in vivo, causing the limited operational stability of sensors in biological media . In addition, Kealy et.…”

Section: Resultsmentioning

confidence: 99%

Long–term Drifts in Sensitivity Caused by Biofouling of an Amperometric Oxygen Sensor

et al. 2016

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Changes in oxygen sensitivity of an poly(o‐phenylenediamine) (PoPD) coated gold electrode was determined by constructing calibration curves in vitro. Oxygen sensitivities recorded in the presence of biofoulants were significantly different from those recorded in buffer; however, PoPD demonstrated its effectiveness in providing some resistance to changes in oxygen sensitivity over time compared to a bare electrode. Three sets of PoPD‐coated electrodes were calibrated in simple electrolyte of phosphate buffered saline; each set yielding an average oxygen sensitivity of 0.58±0.03 μA/ppm, 0.68±0.01 μA/ppm, and 0.48±0.01 μA/ppm (n=4), which shows the electrode to electrode variation in the PoPD‐coating/electrode. These sets were correspondingly exposed to bovine serum albumin, fibrinogen, rat brain homogenate. Exposure to these biofoulants resulted in decreases in sensitivity ranging from 26–35 % after immediate exposure. Furthermore, long‐term exposure to some biofoulants causes significant decreases in sensitivity over a time period of 14 days. We also estimated through in vitro exposure to rat brain homogenate the errors that might be associated with current methods of calibration. Sensitivities to oxygen determined by precalibration resulted in a 50 % error from the sensitivity found in vitro; the error from postcalibration after rinsing resulted in 25 % error.

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Section: Resultsmentioning

confidence: 99%

Long–term Drifts in Sensitivity Caused by Biofouling of an Amperometric Oxygen Sensor

et al. 2016

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“…2 Chemicals important to brain function fall under numerous classifications and include gases, such as oxygen and nitric oxide; ions such as Cl − , Na + , Ca 2+ , and K + ; molecules significant to energy, such as ATP, lactate, and glucose; classical neurotransmitters, such as dopamine, GABA, glutamate, and serotonin; neuropeptides, and more recently bioactive proteins including chemokines and cytokines.…”

Section: 1 Introductionmentioning

confidence: 99%

A review of flux considerations for in vivo neurochemical measurements

Paul

Stenken

2015

Analyst

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The mass transport or flux of neurochemicals in the brain and how this flux affects chemical measurements and their interpretation is reviewed. For all endogenous neurochemicals found in the brain, the flux of each of these neurochemicals exists between sources that produce them and the sites that consume them all within μm distances. Principles of convective-diffusion are reviewed with a significant emphasis on the tortuous paths and discrete point sources and sinks. The fundamentals of the primary methods of detection, microelectrodes and microdialysis sampling of brain neurochemicals are included in the review. Special attention is paid to the change in the natural flux of the neurochemicals caused by implantation and consumption at microelectrodes and uptake by microdialysis. The detection of oxygen, nitric oxide, glucose, lactate, and glutamate, and catecholamines by both methods are examined and where possible the two techniques (electrochemical vs. microdialysis) are compared. Non-invasive imaging methods: magnetic resonance, isotopic fluorine MRI, electron paramagnetic resonance, and positron emission tomography are also used for different measurements of the above-mentioned solutes and these are briefly reviewed. Although more sophisticated, the imaging techniques are unable to track neurochemical flux on short time scales, and lack spatial resolution. Where possible, determinations of flux using imaging are compared to the more classical techniques of microdialysis and microelectrodes.

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“…Both trends entail stringent technology requirements [4]. Precise fabrication of microelectrode arrays is crucial for accurate positioning and definition of the inter-electrode spacing.…”

Section: Introductionmentioning

confidence: 99%

Multisite monitoring of choline using biosensor microprobe arrays in combination with CMOS circuitry

Frey¹,

Rothe²,

Heer³

et al. 2014

Biomedical Engineering / Biomedizinische Technik

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A miniature device enabling parallel in vivo detection of the neurotransmitter choline in multiple brain regions of freely behaving rodents is presented. This is achieved by combining a biosensor microprobe array with a custom-developed CMOS chip. Each silicon microprobe comprises multiple platinum electrodes that are coated with an enzymatic membrane and a permselective layer for selective detection of choline. The biosensors, based on the principle of amperometric detection, exhibit a sensitivity of 157 ± 35 µA mM -1 cm -2 , a limit of detection of below 1 µM, and a response time in the range of 1 s. With on-chip digitalization and multiplexing, parallel recordings can be performed at a high signal-to-noise ratio with minimal space requirements and with substantial reduction of external signal interference. The layout of the integrated circuitry allows for versatile configuration of the current range and can, therefore, also be used for functionalization of the electrodes before use. The result is a compact, highly integrated system, very convenient for on-site measurements.

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Technological Barriers in the Use of Electrochemical Microsensors and Microbiosensors for in vivo Analysis of Neurological Relevant Substances

Cited by 12 publications

References 94 publications

Long–term Drifts in Sensitivity Caused by Biofouling of an Amperometric Oxygen Sensor

Long–term Drifts in Sensitivity Caused by Biofouling of an Amperometric Oxygen Sensor

A review of flux considerations for in vivo neurochemical measurements

Multisite monitoring of choline using biosensor microprobe arrays in combination with CMOS circuitry

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