A sensitive electrochemical sensor for cryptotanshinone based on electrochemical reduced graphene oxide and carbon nanotube composite film modified glassy carbon electrode

The electrodeposition of reduced graphene oxide and carbon nanotube (ErGO/CNTs) composite film modified electrode has been fabricated by electrochemical reduction of graphene oxide (GO) and MWNTs composite film coated on the surface of glassy carbon electrode (GCE). The results show that in 0.2 mol/L NaAc-HAc (pH= 4.5) buffer solution, cryptotanshinone produced a pair of sensitive redox peaks with peak potentials of -0.180 V and -0.207 V (vs SCE). The electrode reaction was two electrons and two protons participate in the completely reversible process of adsorption control. The ErGO/CNTs membrane modified electrode has obvious catalytic and sensitizing effects on the redox of cryptotanshinone. Differential pulse voltammetry (DPV) is used to investigate the relationship between oxidation peak current and cryptotanshinone concentration. It is found that the oxidation current of cryptotanshinone is linear with its concentration in the range of 2.7 × 10-8 ~1.3 × 10-5 mol/L and the determination limit is 1.0 × 10-8 mol/L, which can realize the electrochemical detection of cryptotanshinone in the drug.