▎ 摘　　要

In this paper, we use a simple and cheap approach for the synthesis of herceptin-conjugated graphene biosensor to detect the HER2-positive breast cancer cells. The bifunctional graphene-herceptin nanosheets are prepared from graphite by a simple ultrasonic-mediated technique. The prepared protein-mediated graphene is fully characterized. The results show the exfoliation of graphene layers in herceptin solution. Moreover, herceptin is effectively conjugated into the surface of graphene nanosheets. The synthesized herceptin-conjugated graphene is applied for breast cancer detection. The linear range of this biosensor is 1-80 cells, which is significant. The biosensor shows an excellent selectivity performance for detection of HER2-positive cancer cells. Likewise, the stability and functionality of the biosensor is about 40 days. Based on the results, this device is a promising candidate for rapid and selective detection of cancer cells.