Calix[8]arene functionalized single-walled carbon nanohorns for dual-signalling electrochemical sensing of aconitine based on competitive host-guest recognition

• A dual-signalling competitive electrochemical approach towards aconitine was developed.
• SCX8–SWCNHs nanohybrid was prepared by a green and clean approach.
• SCX8–SWCNHs exhibited excellent supermolecular recognition capability.
• This method showed high sensitivity and selectivity beyond competitive binding analytes.
• The mechanism of the competitive host–guest interaction was clarified.

A dual-signalling electrochemical approach has been developed towards aconitine based on competitive host–guest interaction by selecting methylene blue (MB) and p-sulfonated calix[8]arene functionalized single-walled carbon nanohorns (SCX8–SWCNHs) as the “reporter pair”. Upon the presence of aconitine to the performed SCX8–SWCNHs·MB complex, the MB molecules are displaced by aconitine. This results in a decreased oxidation peak current of MB and the appearance of an oxidation peak of aconitine, and the changes of these signals correlate linearly with the concentration of aconitine. A linear response range of 1.00–10.00 μM for aconitine with a low detection limit of 0.18 μM (S/N=3) was obtained by using the proposed method. This method could be successfully utilized to detect aconitine in serum samples. This dual-signalling sensor can provide more sensitive target recognition and will have important applications in the sensitive and selective electrochemical detection of aconitine.