Design of Optical Nanobiosensors for Detection of Toxic Compounds and Pharmaceutical Products

Demands for developing optical nanobiosensors for controlling the quality of food [1-4], pharmaceuticals [5], environmental activities [6] and industrial processes [7] have encountered an enormous increase over the last decade. A lot of effort was devoted to design highly sensitive and selective methods for that purpose [8]. Sol-gel approach has rapidly become a fascinating new field of research in materials science. The use of nanosystems and organic molecules in the gel formation process to influence the dimensions of the formed pores represents another strategy to construct optical nanobiosensors and increase the immobilized enzyme activity for more efficient sensing. The aim of our work is a construction of optical nanobiosensors based on horseradish peroxidase (HRP) for quantitative and qualitative detection of toxic compounds, contaminants and pharmaceutical products. Different categories of hybrid matrices were fabricated contained silica nanopartices, cellulose derivatives and Poly (amido amine) dendrimers (PAMAM) as perspective carriers for covalent immobilization. Horseradish peroxidase (HRP) was used as a model enzyme. Conditions were optimized, kinetic parameters, pH and temperature optimums were determined. Constructed nanobiosensors were implemented to optically detect compounds like phenol, resorcinol, epinephrine and acetaminophen. Results showed that the highest parameters were achieved by TMOS/CAB/PAMAM based matrices, where records of relative activity reached 92% while having a shift for the optimum pH that recorded 6.5 and the optimum temperature that recorded 40 iC. The applied system demonstrated enhanced operational potential towards designing biosensor for medical, pharmaceutical, food industrty as well as environmental monitoring purposes.