| 1. |
- Alcock, S. J., et al.
(författare)
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Advances in the use of in vivo sensors
- 1992
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Ingår i: Biosensors & bioelectronics. - : Elsevier. - 0956-5663 .- 1873-4235. ; 7:4, s. 243-254
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The sixth workshop of the European Community Concerted Action on Chemical sensors for in vivo monitoring was held at Snogeholm, Sweden, in October 1991. The meeting reviewed recent in vivo and ex vivo results, and also included a shorter session on ethical and safety problems.
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| 2. |
- HU, J, et al.
(författare)
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AN ENZYME ELECTRODE FOR GLUCOSE CONSISTING OF GLUCOSE-OXIDASE IMMOBILIZED AT A BENZOQUINONE-MODIFIED CARBON ELECTRODE
- 1991
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Ingår i: Analytical Letters. - : Taylor andamp;amp; Francis. - 0003-2719 .- 1532-236X. ; 24:1, s. 15-24
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes an amperometric enzyme electrode for the analysis of glucose. The glucose sensor utilised adsorbed benzoquinone on a carbon electrode to mediate electron transfer from glucose oxidase. A linear response to 0-15 mM glucose was observed. The electrodes response to glucose, its pH profile and the effect of temperature are presented.
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| 3. |
- Turner, J. T., et al.
(författare)
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ZOOPLANKTON FEEDING ECOLOGY - GRAZING DURING ENCLOSURE STUDIES OF PHYTOPLANKTON BLOOMS FROM THE WEST-COAST OF SWEDEN
- 1992
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Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier BV. - 0022-0981. ; 157:1, s. 19-31
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Tidskriftsartikel (refereegranskat)abstract
- The effects of grazing on natural phytoplankton populations was examined during enclosure studies on the effects of nutrients, zooplankton, and ctenophores on phytoplankton bloom dynamics on the west coast of Sweden in May, 1990. Grazers included the copepods Acartia clausi Giesbrecht, Centropages hamatus Lilljeborg, and Oithona similis Claus, and the marine cladoceran Podon polyphemoides Leuckart. These species ingested various diatoms, dinoflagellates and athecate microflagellates, but grazing was minimal. Clearance rates of the copepods were < 1 ml.animal-1.h-1, while those of cladocerans reached 2.5 ml.animal-1.h-1, at microflagellate concentrations of 1442-3519 cells.ml-1. Despite the low levels of copepod and cladoceran grazing, there was considerable removal of Chl a by grazers < 90-mu-m in longest dimension. These micrograzers were present in experimental and control containers. Athecate ciliates < 20-mu-m in longest dimension were abundant (up to 1730 cells.ml-1) in some samples, and these ciliates were the most probable micrograzers. Rates of clearance of these ciliates by A. clausi (0.13-0.81 ml.animal-1.h-1) and C. hamatus (0.46-0.81 ml.animal-1.h-1) were high, even though ciliates were less abundant than most co-occurring phytoplankton taxa. Copepod and cladoceran grazing appeared to have little impact on phytoplankton dynamics. Rather, copepods were selective consumers of the ciliates that were probably the dominant grazers.
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| 4. |
- WHITE, SF, et al.
(författare)
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INVESTIGATIONS OF PLATINIZED AND RHODINIZED CARBON ELECTRODES FOR USE IN GLUCOSE SENSORS
- 1994
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Ingår i: Electroanalysis. - : John Wiley andamp;amp; Sons, Ltd. - 1040-0397 .- 1521-4109. ; 6:8, s. 625-632
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Tidskriftsartikel (refereegranskat)abstract
- Graphite electrodes were modified by the electrodeposition of either platinum or rhodium, using cyclic voltammetry. Following only brief periods nf treatment, plantinized carbon electrodes were able to directly oxidize glucose at a potential of +350 mV (vs. Ag/AgCl). By narrowing both the potential range of deposition (-450 to -500 mV) and cycling period (50 seconds at a scan rate of 10 mV s(-1)), the effects of direct glucose oxidation could be significantly: reduced. Detection of H2O2 at +400 mV was possible; glucose enzyme electrodes were constructed, with glucose oxidase immobilized in hydroxyethylcellulose and operated at this potential. These sensors had a linear range of 0.1 to 25 mM glucose and a slope of 8 nA/mM. Other electrodes were prepared by the electrodeposition of rhodium. These base electrodes proved to be insensitive to glucose and produced higher currents (compared to low platinum electrodes) to H2O2. Glucose sensors were constructed using rhodinized electrodes. Again operating at +400 mV, these sensors had a linear range from 0.1 to 20 mM and a slope of 21 nA/mM glucose.
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| 5. |
- WHITE, SF, et al.
(författare)
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LACTATE, GLUTAMATE AND GLUTAMINE BIOSENSORS BASED ON RHODINISED CARBON ELECTRODES
- 1994
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Ingår i: Analytica Chimica Acta. - : Elsevier Science B.V., Amsterdam.. - 0003-2670 .- 1873-4324. ; 295:3, s. 243-251
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Tidskriftsartikel (refereegranskat)abstract
- Amperometric enzyme sensors for lactate, glutamate and glutamine were constructed using rhodinised carbon electrodes. All three sensors operated at a potential of +400 mV (Ag/AgCl). Lactate sensors were constructed using lactate oxidase immobilized in hydroxyethylcellulose, overlaid with a cellulose acetate membrane. Using a flow-injection system, the sensors had a linear range of 0.1 to 1.5 mM. Measurements of lactate concentrations from a mammalian cell culture were compared with results obtained from a commercial instrument. A correlation coefficient of r=0.982 (n = 15) was obtained. Glutamate and glutamine sensors were fabricated based on glutaraldehyde immobilization; the former by incorporating glutamate oxidase and the latter based on glutamate oxidase and glutaminase (both had a linear range of 0.1 to 1.5 mM). The feasibility of using these sensors, in conjunction with a previously described glucose sensor, for mammalian cell culture monitoring is discussed
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