Preparation and characterization of bioanalysis systems to be used in determining phenolic compounds

Along with the increase of industrial wastes in the world, many types of wastes have reached saturation and the losses of these wastes have started to be seen. Phenol and phenol derivatives, which are the most important of these wastes; Explosives, pharmaceuticals, plastics, paper, paint, pesticides and antioxidants. Certain phenols and aromatic compounds are highly toxic, carcinogenic and allergenic, and therefore have a high level of pre-determination and elimination. In order to determine these compounds, colorimetric, fluorometric, turbidimetric, spectrophotometric and enzymatic methods are applied in various media such as waste water and beverages. However, these methods are known to be quite time consuming and expensive systems. With biosensors, it is possible to apply cost-effective, practical and fast-yielding analyzes compared to such systems.In this thesis study, a biosensor was designed using laccase (Lac) enzyme for the determination of phenolic compounds. For this purpose, polyamic acid (PAA) membranes have been used which are easily prepared and allow the enzyme to be immobilized by covalent bonds. First, PAA membranes were synthesized to include anthracene (Ant), a fluorophore. In the ant-PAA construct, Lac enzyme was immobilized by a method that served as glutaraldehyde cross-linker. Oxygen is the basis of the measurement of damping fluorescence intensity of anthracene. During the Lac reaction, the phenolic compounds are oxidized while the oxygen is reduced to water. Fluorescence intensity increases when oxygen is removed from the measurement medium. Based on this principle, quantitative determination of phenolic compounds has been made by correlating the increase in concentration-dependent fluorescence intensity. The optimum pH for the Ant-PAA / Lac system was found to be 5.5. Phenol was determined in the range of 0.05-0.25 mM. In addition, the effect of various compounds likely to interfere with fluorescence intensity was tested and phenol determination was made in synthetic wastewater. In the next step, the antioxidant enzyme Paraoxonase (PON) and Laccase (Lac) enzymes were immobilized together to prepare the Ant-PAA / Lac-PON sensor system. The optimum pH for Ant-PAA / Lac-PON was found to be 8.0 and the detection range for phenyl acetate was found to be 0.01-0.5 mM. Entrepreneurial influence tested. Ciproflakasinin is known to be an inhibitor of PON and the quantitative determination of ciproflakasin was performed using the Ant-PAA / Lac / PON system as an inhibitor-based biosensor.