A novel voltammetric sensor based on poly(l-Citrulline)/SWCNTs composite film modified electrode for sensitive determination of picroside II

• This is the first report about the electrochemical properties and electroanalytical method for picroside II.
• The L-Citrulline was used as the modified materials of electrode for the first time.
• The resulting sensor showed a significant voltammetric response to picroside II and used in real sample with satisfactory results.
• This work promoted the potential applications of amino acid materials and SWCNTs in electro-chemical sensors.

A novel voltammetric sensor was constructed by simple dripping single-walled carbon nanotubes (SWCNTs) on to the glass carbon electrode (GCE) firstly and electro-polymerizing l-Citrulline film subsequently. The resulting poly(l-Citrulline)/SWCNTs/GCE showed a significant voltammetric response to picroside II due to the synergistic effect of SWCNTs and poly(l-Citrulline) film. The first electroanalytical method of picroside II was proposed with detection linear range from 8.0×10−8 to 5.0×10−6 mol L−1 and a detection limit of 3×10−8 mol L−1.The high sensitivity, selectivity and long-term stability made the sensor suitable for the determination of picroside II. Moreover, based on the systematically investigation and some kinetics parameters calculated in the experimentation, the reaction mechanism of picroside II at the poly(l-Citrulline)/SWCNTs modified GCE was obtained reliably. Lastly, the proposed sensor was used for the determination of picroside II in real sample with satisfactory results. This work promoted the potential applications of amino acid materials and SWCNTs in electro-chemical sensors.

Graphical AbstractA novel sensor for high-sensitive determination of picroside II was constructed by simple dripping single-walled carbon nanotubes (SWCNTs) onto the glass carbon electrode (GCE) firstly and electro-polymerizing L-Citrulline film subsequently. Compared with bare GCE, SWCNTs/GCE and poly(L-Citrulline)/GCE, there were dramatic increase of the peak currents. Then the electrochemical behavior of picroside II was carefully and systematically investigated and some kinetics parameters were calculated. The reaction mechanism of picroside II at poly(L-Citrulline)/SWCNTs/GCE was also discussed. A simple and high-sensitive electroanalytical method for picroside II was established using LSV and applied in the drug sample analysis.Figure optionsDownload as PowerPoint slide