Hierarchical Au-Pt Nanostructured Film-Enabled Electrochemical Sensor for Highly-Sensitive Determination of Salvianolic Acid B.

Salvianolic acid B is an important bioactive biomarker in traditional Chinese medicines (TCMs). Current methods for its quantitation are time- and cost-consuming; a rapid and reliable method is urgently needed. In this work, we have developed a simple and sensitive electrochemical (EC) sensor on screen-printed carbon electrode (SPCE) that was modified with three-dimensional hierarchical Au-Pt nanostructured film. This highly conductive structure facilitates direct electron transfer when the sample solution containing salvianolic acid B is dropped, thereby amplifying its generated current response. Under optimized conditions, the fabricated label-free EC sensor exhibited a wide linear range (4-500 μg/mL) with excellent conductivity and a detection limit as low as 3.76 μg/mL for salvianolic acid B, as well as high reproducibility and outstanding stability. Furthermore, the practical applicability was validated by satisfactory spiked recovery rates (97.5-101.4%) in complex Salvia miltiorrhiza matrices. These findings indicated that the Au-Pt nanostructure-modified SPCE could achieve reliable and stable quantitation of salvianolic acid B. The developed EC sensor provided an economical, efficient, user-friendly, and reliable on-site strategy for accurate determination of salvianolic acid B and other components in more TCMs.