Eu-doped chitosan carbon dot/dendritic silver nanostructure-based biosensor for BRAF detection in thyroid cancer exosome

In this work, a novel electrochemiluminescence (ECL) biosensor has been constructed with Eu-doped chitosan carbon dot (Eu: Cs dot) and dendritic silver nanostructure. Firstly, Eu: Cs dots were synthesized as ECL tags, which not only possessed exceptional electrochemical characters and intense luminescence, but also can reacted with H 2 O 2 as co-reactant to generate ECL signal. Furthermore, dendritic silver nanostructure with conductive gel was successfully prepared as sensing interface. The dendritic silver nanostructure with conductive gel displayed the ideal conductivity, good electrochemical stability, which can enhance the ECL intensity of Eu: CS dots. Finally, BRAF V600E from thyroid cancer exosome in the clinic eluate can be captured and detected. The results indicated the relative association between BRAF V600E mutation and lymphatic metastasis, which can be used in assessing thyroid cancer progression for advancing clinical diagnosis applications.