Label-Free Amperometric Immunosensor Based on Au@Pt DNPs/MoSe2@MoS2 with Multiple Signal Amplification Capabilities for Squamous Cell Carcinoma Antigen Detection

Herein, urchin-like gold@platinum dendritic nanoparticles supported on molybdenum selenide@molybdenum disulfide (Au@Pt DNPs/MoSe2@MoS2) nanocomposite with multiple signal amplification capabilities was successfully synthesized as the matrix platform of label-free amperometric immunosensor for the quantitative detection of squamous cell carcinoma antigen (SCCA). Au@Pt DNPs/MoSe2@MoS2 consists of Au@Pt DNPs with splendid biocompatibility as well as catalysis and MoSe2@MoS2 with reformative peroxidase activity, which owned enhanced electrocatalysis toward hydrogen peroxide reduction and steady bioconjugation for bioprotein immobilization. Additionally, Au@Pt DNPs/MoSe2@MoS2 possessed satisfactory conductivity to accelerate electron transfer at the electrode interface. With the help of Au@Pt DNPs/MoSe2@MoS2, the immunosensor procured a good linear extent of SCCA detection between 100 fg ml−1 and 100 ng ml−1, reached a lower detection limit than previous reports. Moreover, the immunosensor with good stability and reproducibility achieved the specific detection of SCCA in the mixture containing interferents as well as in the real human serum sample, which testified to the proposed amperometric immunosensor was reliable in clinical detection of tumor biomarkers.