摘要
In this study, we leveraged the synergistic effect of nitrogen and sulfur co-doped graphene quantum dots (NSGQDs) and three-dimensional gold nanostars (AuNS) in the hybrid material of AuNS@NSGQDs for constructing a label-free electrochemical biosensor. Accordingly, the as-prepared AuNS@NSGQDs nanocomposite was simply drop-casting onto the screen-printed platinum electrode (SE), followed by conjugating with phytohemagglutinin-L (PHAL) to form the SE = AuNS@NSGQDs/PHAL sensor probe. This sensor probe was then employed for the detection of MCF-7 breast cancer cells via electrochemical impedance spectroscopy (EIS) technique, showing a good electrochemical performance in a wide linear range of 10–10 5 cells mL −1 with a low detection limit of 3 cell mL −1 . Intriguingly, the remarkable analytical performance of sensing platform for MCF-7 is primarily attributed to the excellent electrochemical properties of AuNS@NSGQDs, and the support of PHAL serving as an effective anchoring agent for the selectively capturing of MCF-7 breast cancer cells. Furthermore, the selectivity of sensor probe toward MCF-7 is performed over different co-existing cancer cells, highlighting its high specificity that plays a crucial role in clinical applications. The sensor also displays high stability and reproducibility, maintaining performance over a storage period of 100 days while sustaining functionality over 30 consecutive cycles of reuse. Besides, the biocompatibility and low cytotoxicity of AuNS@NSGQDs nanocomposite are observed at high concentrations, indicating a negligible effect on the MCF-7 cell line, underscoring its safety for biosensor applications. This achievement of biosensor using AuNS@NSGQDs electrode provides a robust platform for rapid detection of MCF-7 with high accuracy and specificity, facilitating early diagnosis and therapy of diseases, particularly in the context of breast cancer.