MoS2 nanosheets grown on bowl-shaped hollow carbon spheres as an efficient electrochemical sensor for ultrasensitive determination of nephrotoxic aristolochic acids in Chinese traditional herbs

Abstract

Aristolochic acid, a substance in herbs, is highly nephrotoxic, so it is crucial to develop an assay that can rapidly and accurately analyze its content. In this study, bowl-shaped hollow carbon spheres (BHCs) were synthesized using a complex template method, and a MoS₂ layer was grown in situ on their surface using a hydrothermal method. The synthesized MoS₂–BHCs were used to fabricate an electrochemical sensor for the ultrasensitive and highly selective detection of aristolochic acids (AAs). The optimal conditions for AA detection were determined by tailoring the amount of MoS₂ used to modify the BHCs and the pH of the electrolyte. Under optimal conditions, the MoS₂–BHC-based sensor presented excellent AA detection performance. The linear concentration ranges of the MoS₂–BHC-based sensor for the detection of AA were 0.05–10 μmol L⁻¹ and 10–80 μmol L⁻¹, and the limit of detection of the sensor was 14.3 nmol L⁻¹. Moreover, the MoS₂–BHC-based sensor detected AA in Aristolochia and Asarum sieboldii samples. The results were consistent with high-performance liquid chromatography data, demonstrating the satisfactory recovery and accuracy of the sensor. Therefore, we believe that MoS₂–BHC-based sensors can be used as effective platforms for detecting AA in traditional Chinese herbs.