No abstract

5-Aminosalicylic acid is an antiinflammatory drug used to treat inflammation of the digestive tract (Crohns disease) and mild to moderate ulcerative-colitis. 5-Aminosalicylic acid is a bowel-specific aminosalicylate drug. It was developed an amperometric biosensor for determination of 5-aminosalicylic acid concentration and measurement technique is based on substrate-competition. The biosensor is more suitable especially for routine 5-aminosalicylic acid analysis because it is simple to construct and sensitive, specific and does not require any expensive apparatus. This enzyme based biosensor was made with a couple of enzymes which uses the same substrate. The electrode was developed to determine measurement conditions and also characterized.

A low-cost and sensitive amperometric biosensor was developed for the determination of α-amylase activity. The biosensor was constructed by immobilizing glucose oxidase-gelatin via glutaraldehyde on the Au electrode surface. Measurements were carried out chronoamperometrically at -0.7 V. Several parameters such as glucose oxidase activity, gelatin amount, and glutaraldehyde percentage for cross-linking were optimized. Optimum pH, optimum temperature, repeatability, and storage stabilities of the biosensor were identified. Under the optimum experimental conditions, a linear calibration curve was obtained for α-amylase between 0.819 and 13.110 U/ml. Sample analyses were carried out by detecting α-amylase activities in baker's yeast samples.

A glucose oxidase-based biosensor was developed for the determination of α-amylase activity. The determination method is based on monitoring the decrease in dissolved oxygen concentration related to the starch concentration, for which starch gives a reaction with α-amylase. Optimization parameters, including glucose oxidase amount, gelatin amount, and glutaraldehyde percentage for cross-linking, were investigated. The effects of pH, buffer system, and temperature on the biosensor system were also investigated. The biosensor had a linear relation to α-amylase activity and good measurement correlation between 0.66 and 9.83 U/ml. In sample analysis studies, α-amylase activity in baker's yeast was determined by the biosensor.

In the study, we investigated the practicality of the UV polymerization of aniline for anti-aflatoxin B1 antibody immobilization, and utilization of the resulting biosensor in the impedimetric determination of aflatoxin B1. The anti-aflatoxin B 1 antibody was physically immobilized on gold electrodes by UV polymerization of aniline at a fixed wavelength. The biosensor was based on specific interaction anti-aflatoxin B1 - aflatoxin B1 recognition and investigation of this recognition event by electrochemical impedance spectroscopy. A calibration curve was obtained in a linear detection range 1-20 ng/mL aflatoxin B1. Finally, the biosensor was applied to analysis of a real food sample.