Gold Nanoparticles Like A Matrix For Covalent Immobilization Of Cholesterol Oxidase – Application For Biosensing

Abstract

Abstract Gold nanoparticles are emerging as promising agents for various areas of material science as well as nanotechnology, electronics and medicine. The interest in this material is provided due to its unique optical, electronic and molecular-recognition properties. This paper presents results of preparation, characterization and biofunctionalization of gold nanoparticles. Nanoparticles have been conjugated with the cholesterol oxidase enzyme in order to prepare the active element for biosensors. Cholesterol oxidase is one of the most important analytical enzyme, used for cholesterol assay in clinical diagnostics, and there is still a necessity in improvement of existing analytical techniques, including bio-nanotechnological approaches based on modern nanosystems. The prepared bio-nanosystem was characterized by the enzyme activity test. Obtained results showed a stable binding of the enzyme with nanoparticles and preserved the bioactivity approves which gives possibility to use the prepared bio-nanosystems for analytical purposes. The Surface Plazmon Resonance and the Surface Enhanced Raman Scattering as specific for nanocurriers effects were observed what enable us to research the oscillation spectra of enzyme. These spectra were compared with ones obtained by IR-spectroscopy. The vibrational lines are attributed to chemical functional groups existing in enzyme, for example, amino acids, amide groups as well as flavin – adenine dinucleotide cholesterol oxidase prosthetic group. By this way the identified spectral lines can be used as a distinguishing mark of enzyme.