Research

The aim of the research work is the production of sensitive new sensors consisting of multi-walled carbon nanotubes and their modification with metallic nanoparticles and their application for the simultaneous electrochemical analysis of various biomolecules. In addition to undoped multi-walled carbon nanotubes, nitrogen-doped, phosphorus-doped, sulfur-doped and boron-doped carbon nanotubes are synthesized and characterized. The nanostructures are deposited on a silicon/silicon oxide substrate using a catalytic pyrolysis process by the decomposition of carbon, nitrogen, phosphorus, sulfur and boron-containing organic compounds in the presence of the catalyst. To further customize the electrocatalytic properties, the doped multi-walled carbon nanotubes are modified with nanoparticles of rhodium, palladium, iridium, platinum, silver and gold. The modified layers produced are used for the simultaneous electrochemical analysis of important biomolecules such as dopamine, ascorbic acid and uric acid in a blood model system.

Nitrogen-doped carbon nanotubes modified with gold nanoparticles show a particular sensitivity for the simultaneous electrochemical detection of the biomolecules investigated (dopamine, ascorbic acid and uric acid). On these particular sensors, detection limits were obtained significantly better (lower) compared to numerous published data. The results show that the electrochemical quality of the fabricated carbon nanotube sensors is excellent. Nanoparticle-modified carbon nanotube sensors can also be used for the electrochemical analysis of other interesting biomolecules such as epinephrine, N-acetylcysteine, acetaminophen and glucose with very good results. Both the non-enzymatic electrochemical oxidation of glucose in the presence of uric acid and the simultaneous analysis of N-acetylcysteine and acetaminophen were investigated using gold nanoparticle-modified nitrogen-doped carbon nanotubes. In addition, the simultaneous analysis of dopamine-uric acid and epinephrine-uric acid binary systems on boron-doped carbon nanotubes modified with gold nanoparticles was successfully performed.