Highly sensitive detection of salvianic acid a drug by a novel electrochemical sensor based on HKUST-1 loaded on three-dimensional graphene-MWCNT composite.

HKUST-1, a kind of metal-organic framework (MOF) composed by Cu2+ and trimesic acid, loaded on reduced graphene oxide and multi-walled carbon nanotubes nanocomposite [HKUST-1 @ (RGO-MWCNT)] was successfully synthesized by a facile and simple route. Then, a highly sensitive non-enzymatic salvianic acid A (SAA) electrochemical sensor was fabricated by modifying HKUST-1 @ (RGO-MWCNT) on a glassy carbon electrode, taking full advantage of the synergistic effect between the redox catalytic capacity of Cu2+ and the electrical conductivity of carbon materials. The sensor showed a low limit of detection of 0.081 μM, limit of quantitation of 0.27 μM, high sensitivity of 509.6 μA/mM and a good relationship between reduction peak current and concentration of SAA from 2 to 4600 μM. Meanwhile, the sensor had the advantages of repeatability and stability. Finally, it was used to detect SAA in real samples with noteworthy electroanalytical performance. In short, the sensor has considerable potential for the electroanalysis of SAA. Moreover, the study provides a promising composite of MOF and carbon materials with potential application in the analysis of effective components of herbaceous medicinal plants.