Application of nitrogen-doped multi-walled carbon nanotubes decorated with gold nanoparticles in biosensing

Novel films consisting of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) were fabricated by means of chemical vapor deposition technique and decorated with gold nanoparticles (AuNPs) possessing diameter of 14.0 nm. Electron optical microscopy analysis reveals that decoration of N-MWCNTs with AuNPs does not have any influence on their bamboo-shaped configuration. The electrochemical response of fabricated composite films, further denoted as N-MWCNTs/AuNPs, towards oxidation of dopamine (DA) to dopamine-o-quinone (DAQ) in the presence of ascorbic acid (AA) and uric acid (UA) was probed in real pig serum by means of cyclic voltammetry (CV) and square wave voltammetry (SWV). The findings demonstrate that N-MWCNTs/AuNPs exhibit slightly greater electrochemical response and sensitivity towards DA/DAQ compared to unmodified N-MWCNTs. It is, consequently, obvious that AuNPs improve significantly the electrochemical response and detection ability of N-MWCNTs. The electrochemical response of N-MWCNTs/AuNPs towards DA/DAQ seems to be significantly greater compared to that of conventional electrodes, such as platinum and glassy carbon. The findings reveal that N-MWCNTs/AuNPs could serve as powerful analytical sensor enabling analysis of DA in real serum samples.

Automated summary

Novel films of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) were prepared by chemical vapor deposition and decorated with 14.0 nm gold nanoparticles (AuNPs). Electron microscopy analysis showed that AuNPs decoration did not affect the bamboo-shaped configuration of N-MWCNTs. Electrochemical response of the fabricated composite films (N-MWCNTs/AuNPs) towards dopamine oxidation was studied in real pig serum, demonstrating slightly enhanced sensitivity compared to unmodified N-MWCNTs. The findings suggest that AuNPs significantly improve the electrochemical response and detection ability of N-MWCNTs, making them a powerful analytical sensor for dopamine analysis in real serum samples.