doi: 10.1080/00032719108052969pmid: N/A
Abstract This is a scanned image of the original Editorial Board page(s) for this issue.
Suleiman, Ahmad A.; Guilbault, George G.
doi: 10.1080/00032719108052972pmid: N/A
Abstract The recent development of piezoelectric immunosensors is reviewed. The selectivity provided by the biological coatings together with the inherent sensitivity of the PZ devices and the ability to oscillate the crystal in liquid medium have induced a rising interest in this class of sensors. Methods of coating and several applications are reported including microgravimetric immunoassays, microbial assays and gas phase immunosensors.
Amine, A.; Kauffmann, J-M.; Patriarche, G. J.; Kaifer, A.E.
doi: 10.1080/00032719108052973pmid: N/A
Abstract The amperometric response of a mixed-glucose oxidase-redox mediator-carbon paste electrode, permanently poised at the operating potential, has been investigated in phosphate buffer as a function of glucose concentration over a period of four weeks.
Bernabei, M.; Cremisini, C.; Mascini, M.; Palleschi, G.
doi: 10.1080/00032719108052974pmid: N/A
Abstract Pesticides as paraoxon and aldicarb have been determined with an amperometric hydrogen peroxide based choline sensor. These pesticides inhibit the enzyme acetylcholinesterase which in presence of its substrate, acetylcholine, produces choline. When these pesticides are in presence of acetylcholinesterase, the activity of this enzyme decreases; this causes a decrease of choline production which is monitored by a choline sensor and correlated to the concentration of pesticide in solution. Two different procedures were followed: one with both the enzymes acetylcholinesterase and choline oxidase immobilized, the second one with the acetylcholinesterase in solution and the choline oxidase immobilized. Parameters as pH, buffer, enzyme concentration, substrate concentration and reaction and incubation times were optimized. Results showed that these compounds can be detected in the range 10 – 100 ppb. The use of the enzyme in solution gave the best results with a detection limit of 2 ppb pesticide.
doi: 10.1080/00032719108052975pmid: N/A
Abstract Ultrasensitive and specific biosensors have been developed in our group, based either on electrochemical or optical transducers closely associated with a sensing layer including specific immobilized enzyme systems. H2O2 generated in enzymic reactions catalyzed by oxidases, could be either detected electrochemically on a platinum electrode or optically monitored in the presence of peroxidase using luminol mediated chemiluminescence. The detection of ATP and NAD(P)H involved in numerous analysis of biological samples could be also achieved at the picomole level with photobiosensors using bioluminescence enzymes either from firefly or bacterial origin. By using auxiliary enzymes in combination with these enzymic systems, the stereoselective detection of variety of analytes could also be conducted in complex mixtures. No pretreatment of the sample, even turbid, was required, avoiding difficulties encountered when classical spectroscopic methods are used. Only a few microliters of sample were necessary making such devices attractive in various domains of biotechnology, biomedical engineering or environment control.
Glazier, Scott A.; Rechnitz, Garry A.
doi: 10.1080/00032719108052976pmid: N/A
Abstract The preparation and characterization of rabbit and bovine IgG-coated membranes is discussed. The performance of these membranes in a competitive binding assay for rabbit IgG and in a sandwich assay for rabbit anti-bovine IgG were used to judge the potential usefulness of these membranes as solid phases for enzyme immunosensors. In particular, these membranes were intended for use in enzyme immunosensors based on the ammonia gas-sensing electrode which employed urease labeled immunoreagents.
Warsinke, Axel; Renneberg, Reinhard; Scheller, Frieder
doi: 10.1080/00032719108052977pmid: N/A
Abstract An amperometric enzyme sensor for the determination of gluconolactone in glucose-containing samples has been developed. The interfering glucose is eliminated by an outer anti-interference layer containing hexokinase, whilst the gluconolactone reaches a glucose de-hydrogenase-glucose oxidase layer, where it is converted into glucose (by glucose dehydrogenase) and then transformed by glucose oxidase, the associated oxygen consumption can be measured at the electrode. Gluconolactone is determined over the concentration range, 0.02–1 mmo1/1, with a toleration of glucose concentration up to 2 mmo1/1.
doi: 10.1080/00032719108052978pmid: N/A
Abstract An enzyme electrode is described for the determination of cholesterol dissolved in chloroform/hexane (1:1). The enzyme electrode is shown to be applicable to the determination of cholesterol in samples of butter and margarine.
doi: 10.1080/00032719108052979pmid: N/A
Abstract Batch injection analysis (BIA) is a new non-flow technique involving the injection of microliter samples toward a nearby detector, immersed in a large-volume blank solution. This paper describes the characteristics and advantages of employing thermal sensing devices as detectors for BIA. Similar to analogous flow injection measurements, batch injection thermal analysis offers high speed, reproducibility and simplicity, while eliminating the need for pumps, valves and associated tubing. There is no observable carryover and the precision is typically 2% (RSD). The batch injection thermal analysis is illustrated for enzymatic reactions, as well as redox and acid-base reactions.
Showing 1 to 10 of 18 Articles