1,721,325 research outputs found
Environmental Toxicology Monitoring with Polyazetidine-based Enzymatic Electrochemical Biosensors
No full textPolyazetidine prepolymer (PAP) has been employed since two decades as immobilizing agent for proteins in biosensors development; some of them are suitable for determination of toxics and pollutants either in inhibition or direct analysis. PAP immobilization procedure is a combination of physical entrapment and chemical cross linking towards several moieties in the proteins; the most interesting features displayed by the obtained layer are the permeability towards both analytes and electrochemical mediators and the formation of an aqueous microenvironment suitable to preserve a native-like structure of immobilized enzymes. Furthermore PAP layer ensure an optimal contact time between the enzyme and the analytes to be determined particularly important for the inhibition based biosensor configuration. Examples of determination of pesticides, herbicides, phycotoxins, biogenic amines and polyphenols with PAP-based biosensors, are described herein
Electrolysis: A Chance To Talk About Chemistry, But Also History, Economics, Environment
No full textMETHOD TO DETERMINE THE TOXICITY CAUSED BY EXPOSURE TO CHEMICAL AND PHYSICAL AGENTS
No full textIt is described a method to determine the toxicity caused by exposure to chemical and physical agents consisting in exposing some biological material to said agents and in measuring with an oxygen electrode the O2 concentration change which is due to the respiratory activity of said material, after having added a convenient substratum to the solution with which the material is in contact, said method being characterised in that the biological material used is such that, at the maximum speed of its metabolism, the residual concentration of O2 is higher than zero
Immobilised Yeast Cells Biosensor for Total Toxicity Testing
No full textAn immobilised yeast cell biosensor has been developed for the total toxicity testing of a sample that may contain a number of different pollutant species; the biosensor uses an amperometric gas diffusion oxygen as indicator electrode. The method is based on the perturbation of the respiratory activity of a yeast, Saccharomyces cerevisiae, immobilised on an agar gel containing the culture medium (i.e., 'agarised medium'), by the toxic test substance. Glucose is used as substrate while the toxic substances tested consist of several metallic ions, phenol and cationic or anionic surfactants
Un nuovo biosensore a lieviti immobilizzati per misure di tossicità integrale
No full textInquinament
L’Approccio Sistematico nella Scelta dei Solventi Organici per la Pulitura dei Reperti Artistici: un Percorso Multidisciplinare tra Scienza e Restauro
No full text
Superoxide Dismutase Biosensors for Superoxide Radical Analysis
No full textSome basic work has been performed on the development and optimisation of superoxide dismutase (SOD) biosensors for superoxide radical analysis. Initially we studied the possibility of obtaining a SOD biosensor using the Clark electrode as indicating sensor. However, the best results were obtained using as indicator a classical amperometric electrode for H2O2 In both cases the superoxide radical was generated in situ using the xanthine/xanthine oxidase (XOD) enzyme system, while the SOD was immobilised in kappa-carrageenan gel. The first application was realised by studying the effects in vitro on the superoxide radical of some molecules commonly accepted as radical scavengers
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