Amperometric response of the HRP-AuNCs/SWCNTs/CFUME (a), HRP/SWCNTs/CFUME (b), SWCNTs/CFUME (c), HRP-AuNCs/CFUME (d), HRP/CFUME (e) and CFUME (f) in 0.01 M PBS buffer solution containing 10 μM H2O2.

The amperometric responses of HRP-AuNCs/MWCNTs/CFUME (a), HRP/MWCNTs/CFUME (b)、MWCNTs/CFUME (c)、HRP-AuNCs/CFUME (d)、HRP/CFUME (e) and CFUME (f) to the addition of H₂O₂ were compared in 0.01 M PBS. The applied potential was chosen on -0.1 V (vs. Ag/AgCl sat. KCl), which can effectively reduce possible interferences and results in high selectivity to H₂O₂. In F. S3, MWCNTs/CFUME (c), HRP-AuNCs/CFUME (d), HRP/CFUME (e) and CFUME (f) gave no response to 10 μM H₂O₂. The response of HRP-AuNCs/MWCNTs/CFUME (a) is obvious and more than 30 times of that from the HRP/MWCNTs/CFUME. The electrodes without HRP or MWCNTs have no response. This result suggests that HRP-AuNCs/MWCNTs/CFUME is overwhelming in amperometric measurement.