1,721,158 research outputs found
Sviluppo di un saggio immunoenzimatico con rivelazione elettrochimica per la determinazione di aflatossina B1
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Microdialysis and glucose biosensor for in-vivo monitoring
No full textMicrodialysis coupled to a glucose biosensor led to a continuous monitor system in vivo for glucose. Several microdialysis probes were used to stabilize the biosensor response. In vivo experiments, especially when the probe was placed subcutaneously, showed that the sensitivity of the biosensor decreased continuously; various kinds of fibers with a molecular weight cut-off (MWCO) ranging from 6 000 to 20 000 were compared. A wall-jet flow cell as detector for glucose showed less interference when compared to a thin layer cell. Glucoday, a new commercial instrument based on this principle, is presented
Ammonium content, nitrogenase activity and heterocyst frequency within the leaf cavities of Azolla filiculoides Lam
No full textIon selective new microelectrodes have been used to measure the ammonium concentrations within the various leaf cavities from the apical to the basal ones, of Azolla filiculoides Lam. Ammonium is present in solution within all leaf cavities, and its concentration varies considerably from the apex to the base. Median leaf cavities, which have the highest rate of nitrogenase activity, contain 0.6–0.8 mM of ammonium and exhibit numerous cyanophycin granules accumulated within the Anabaena vegetative cells. Basal cavities contain 6 mM ammonium, the lowest nitrogenase activity and lowe cyanophycin granules in Anabaena. The mechaniems involved in ammonium accumulation in the basal leaf cavities are discussed
Subcutaneous microdialysis probe coupled with glucose biosensor for in vivo continuous monitoring
Full text linkAffinity-Based Biosensors As Promising Tools For Gene Doping Detection
No full textInnovative bioanalytical approaches can be foreseen as interesting means for solving relevant emerging problems
in anti-doping control. Sport authorities fear that the newer form of doping, so-called gene doping, based on a misuse of gene therapy, will be undetectable and thus much less reventable. The World Anti-Doping Agency has already asked scientists to assist in finding In this Opinion article we discuss the main aspects of gene doping, from the putative target analytes to suitable sampling strategies. Moreover, we discuss the potential application of affinity sensing in this field, which so far has been successfully applied to a variety
of analytical problems, from clinical diagnostics to food and environmental analysis
An L-lactate sensor with immobilized enzyme for use in in vivo studies with an endocrine artificial pancreas
No full textWe report the features of a sensor for determining L-lactate. An oxygen sensor, coupled to a nylon net with chemically bound L-lactate oxidase (EC 1.1.3.2), is inserted into an artificial pancreas (Biostator, Miles) "downstream" from the glucose sensor. We used the sensor to continuously monitor the L-lactate concentration in blood after a "glucose clamp" experiment with a diabetic patient. L-Lactate determinations in blood drawn from the patient every 15 min agreed well with results obtained by use of the L-lactate sensor
Deoxyribonucleic acid (DNA) biosensors for environmental risk assessment and drug studies
No full textAmperometric acetylcholine and choline sensors with immobilized enzymes
No full textAcetylcholine and choline sensors are prepared by immbilizing enzymes on nylon net attached to a hydrogen peroxide snsor. Choline oxidase is used for the choline sensor; acetylcholinesterase choline oxidase are used for acetylcholine. The platinum/silver electrode pair is polarized at +0.6 V. The assembly is protected with an acetate cellulose membrane to enhance selectivity. The ranges measured are 1–10 μmol l−1 in 0.1–1 ml of sample. The response times are 1–2 min
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