Highly Sensitive Electrochemical Sensor Based on PEDOT:PSS-β-CD-SWCNT-COOH Modified Glassy Carbon Electrode Enables Trace Analysis Shikonin

An electrochemical sensor based on PEDOT:PSS-β-CD-SWCNT-COOH/GCE for highly sensitive analysis of shikonin (SHI) in PBS buffer solution was reported. PEDOT:PSS-β-CD-SWCNT-COOH composite was obtained by using poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS), β-Cyclodextrin (β-CD) and carboxylated single-walled carbon nanotube (SWCNT-COOH) to modify glassy carbon electrode (GCE) and characterized by scanning electron microscopy and electrochemical impedance spectroscopies. In optimized conditions, PEDOT:PSS-β-CD-SWCNT-COOH had a high sensitivity to SHI and it could detect SHI in linear ranges 6 nM to 30 μM with a low detection limit of 1.8 nM. And a series of experiments showed that the modified electrode exhibited good repeatability, reproducibility, and selectivity to electrochemical determination of SHI.