Browsing by Author "Griesmar P."

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    Influence of Ni2+ on urease activity produced by biofilms of Arthrobacter oxydans 1388
    (2014-01-01) Marinkova D.; Yotova L.; Ringeard J.; Griesmar P.
    New TiO2-based hybrid materials composed of an organic polymer, cellulose acetate butyrate and copolymer of acrylonitrile acrylamide (AN + AA) were prepared. The effectiveness of immobilization of microbial strain Arthrobacter oxydans 1388 on the newly synthesized hybrid membranes was investigated by biochemical methods. The obtained results revealed that the matrix more suitable for biofilm formation was composed of organic polymers without a metal component in the membrane composition. The influence of Ni2+ on urease activity produced by biofilms was investigated. The experimental results demonstrated that 2 mg L -1 concentration of Ni2+ in the nutrient medium is more appropriate for biofilm proliferation. © 2014 The Author(s). Published by Taylor & Francis.
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    Quartz crystal microbalance detection of aflatoxin B1 by self-assembled monolayer technique
    (2019-01-01) Raykova R.; Marinkova D.A.; Semerdzhieva V.A.; Michiel M.; Griesmar P.; Mourdjeva M.; Yaneva S.; Iliev I.T.
    Background: New biosensor techniques allowing detection of low concentrated substances show a great variety nowadays. The construction of a system with modified quartz as a part of a Quartz Crystal Microbalance (QCM) techniques helps the detection and confirmation of low toxin concentrations in a sample. Objective: The study aims to allow the application of methods for preparation and modification of the gold surface of piezoelectric crystal for detection of aflatoxin B1(AFB1) in the concentration range 0.2-2.0 µg/L by QCM technique (quartz-crystal microbalance). Methods: The procedure for the preparation of quartz crystal sensors for experimental purposes was performed. The quartz surface was activated and covered with self-assembled monolayer to immobilize antibody (rabbit anti-aflatoxin B1) for the detection of antigen-antibody reaction. Results: The G” corresponds to viscous properties of the material, during applied deformation of the material in the presence of different concentrations, which revealed in the sensitivity of the used resonator. Conclusion: Detection of toxic pollutants may be achieved via QCM methods, ultrasound resonator and piezoelectric quartz techniques for measurement. These techniques allow detection of significantly low concentrations of toxic pollutants, in particular, AFB1, compared to analysis with direct and indirect ELISA immunoassays.