DESIGN OF OPTICAL BIOSENSOR BASED ON ENZYME IMMOBILIZATION FOR DETERMINATION OF OXIDIZABLE DRUGS
AHMED HASSAAN1*, SPASKA YANEVA2, LYUBOV YOTOVA1*, ROSITSA BETCHEVA3
1 – Department of Biotechnology, University of Chemical Technology and Metallurgy
2 – Department of Fundamentals of Chemical Technologies,University
of Chemical Technology and Metallurgy
3 – Department of textiles and leather, University of Chemical Technology and Metallurgy
*Corresponding author: lkyotova@yahoo.com; ahmed.hassaan@ymail.com
Keywords: Optical biosensor, hybrid membranes, enzymes, drugs determination
Abstract: With the increased demand to monitor samples contaminated with small amounts of drugs and toxic compounds, our work aimed at constructing optical biosensor based on horseradish peroxidase (HRP) for quantitative and qualitative detection of oxidizable drugs and toxic compounds in the presence of hydrogen peroxide. HRP was covalently immobilized onto new hybrid membranes synthesized by sol-gel technology. Different types of hybrid membranes were synthesized based on silica precursors, cellulose acetate butyrate (CAB), and PAMAM dendrimers. Horseradish peroxidase was used as a model enzyme. Conditions were optimized including kinetic parameters, pH, and temperature optimums. Results showed that the highest enzyme immobilization and catalytic parameters were achieved by TMOS/CAB/PAMAM based matrices, where relative activity recorded was 90 and 92% for phenol and resorcinol detection respectively, compared to the free HRP, while relative activity of 74% and 85% was measured in the case of CAB/PAMAM based matrices.
The applied system demonstrated enhanced operational potential towards designing biosensor for medical, food industry as well as environmental monitoring purposes.