▎ 摘　　要

Recently, great efforts have been made to use biosensors for the early diagnosis of cancer. Specifically, using a biomarker to detect H2O2 in physiological conditions is of great significance for understanding the signal transduction pathways and achieving early cancer diagnosis. In this work, we report an innovative H2O2 sensor that was fabricated by trimetallic AuPtPd nanocomposites platform on reduced graphene oxide (rGO) nanosheets with the modification of the rGO and trimetallic AuPtPd nanoparticles on a glassy carbon electrode (GCE) by physical adsorption. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were utilized to characterize and identify these unique nanocomposites. In addition, the electrochemical properties of the proposed sensor were evaluated by cyclic voltammetry and chronoamperometry. Electrochemical research has demonstrated that the AuPtPd/rGO-modified GCE showed excellent electrocatalytic activity towards the reduction of H2O2, including a wider linear range from 0.005 mu M to 6.5 mM, a low detection limit of 2 nM, good selectivity and acceptable repeatability. Moreover, the sensor can monitor the release of H2O2 release from living cancer cells. Therefore, this study not only improves simplicity, sensitivity and quantitatively for detection H2O2 in cells at nM level but also provides a foundation for the biological and biomedical applications such as the early diagnosis of cancer.