PRODUCTION, MORPHOLOGY AND ELECTROCHEMICAL PROPERTIES OF HYBRID MATERIALS TRYPSIN - CARBON NANOTUBES
DOI:
https://doi.org/10.17308/kcmf.2018.20/526Keywords:
trypsin, carbon nanotubes, printed electrodes, biosensor, volt-ampere characteristics, electrochemical cell.Abstract
This study is dedicated to trypsin – carbon nanotube hybrid materials, and the possibility of their use in biosensor devices. The morphology of the enzyme – nanotube materials have been studied with AFM microscopy. The volt-ampere characteristics of the materials have been measured with potentiometric methods. It has been shown that the enzyme interacts with the carbon nanotube in the solution by covering its surface and creation of a hybrid material without tis inactivation. The pure enzyme on the surface of mica creates small peaks protruding from the porous surface of the substrate. They have a height of 6 to 7 nm. The quaternary globular structures of the enzyme is visible. When creating hybrid materials using trypsin, carbon nanotubes play an important role, which radically change the adhesion of the enzyme to the surface, which leads to the appearance of isolated clusters of a hybrid material. The surface of nanotubes is completely covered by the enzyme. In this case, structures with a maximum height of 9 nm to 11 nm are formed. It has been shown that the volt-ampere characteristic of the resulting hybrid material is sensitive to the presence of casein. The curves of the I-V characteristic have characteristic peaks in the range of 500 and 700 microvolts. The tests with electrodes modified with hybrid materials showed better response times than electrodes modified with pure trypsin. It is likely that hybrid materials contribute to the linearity of the voltmetrometric characteristics when detecting the casein.
It has been shown that the screen-printed electrodes modified by trypsin and carbon nanotubes are promising in use in the food industry to detect casein in raw materials.
ACKNOWLEDGEMENTS
We thank Holyavka Marina G. and Koroleva Viktoria A. for assistance with experiments and measurements.
The research results were obtained with equipment of Voronezh State University Centre for Collective Use of Scientific Equipment.
