Recently it was shown that single-walled carbon nanotubes(SWCNTs) is a suitable support for non-mediated bioelectrocatalytic dioxygen reduction using the enzyme laccase. Further, it was revealed that the use of SWCNTs non-covalently functionalised with pyrene sulfonic acid through π-electron stacking significantly enhances the catalytic activity of the electrode. [1] However, the mechanism behind this enhancement is still not elusidated. Since similarly high catalytic currents were measured using electrodes modified with sulfonated carbon nanoparticles [2], as well as with nafion on multi-walled carbon nanotubes [3] it is suspected that the sulphor groups might be significant for the process.

In this communication we have investigated the electrocatalytic effect of SWCNT-supported laccase, where the SWCNTs have been functionalised with different pyrene compounds. The results are discussed in the light of trying to reveal important parameters for the direct electron transfer.

This research was partially supported by the European Union within the European Regional Development Fund, through Grant Innovative Economy (POIG.01.01.02-00-008/08).

[1]    M. Jönsson-Niedziolka et al., Electrochem. Commun. 11, 1042 (2009).
[2]    K. Szot et al., Electrochim. Acta 54, 4620 (2009).
[3]    K. Stolarczyk et al., Electrochim. Acta 53, 3983 (2008).