Material Science and Engineering

Biography

Biography: Ilker Polatoglu

Abstract

The enzymatic biosensors show remarkable advantage with respect to spectrophotometric and chromatographic techniques in order to determine the pesticide residue, phenolic compound and also GDO at low level. It is possible to detect the low level of analyte by enhancing the sensor signal. In this respect, the key factor is immobilization of enzyme to the appropriate support material. Recently magnetic nanomaterials are becoming the focus of researchers due to their special properties such as strong superparamagnetism, low toxicity and large surface area provides high enzyme loading. Some stabilizers (surfactants, metal nanoparticles and polymeric compounds) have been used to prevent aggregation of magnetic nanomaterials. Among them natural polymer “chitosan” possess several features including biodegradable, biocompatible, bioactive, nontoxic, film forming ability, physiological inertness and high mechanical strength. In this study, tyrosinase enzyme will be immobilized on magnetite (Fe3O4)-chitosan nanocomposite film. According to the preliminary data it is thought to be enhance the sensor signal, since Fe3O4 nanoparticles provide another pathway for electron transfer. The sensor components (chitosan film, Fe3O4 nanoparticles, Fe3O4 nanoparticle-chitosan support and tyrosinase-Fe3O4-chitosan nanobiocomposite film) will be characterized by AFM, FTIR and SEM to reliaze the surface morphology, binding mechanisms and surface image of each material respectively. The analytical performance of the developed sensor will be tested by using electrochemical measurement (cyclic voltometry and amperometry). Catechol will be used as substrate to monitor sensor signal (the electrochemical reduction of enzymatically produced product “o-quinones” to the catechol) as follows. catechol + tyrosinase (O2) ---> o-quinone + H2O (1) o-quinone + 2H+ +2e− ---> catechol (at electrode) (2)