The detection of circulating tumor cells
(CTCs) with a specific antigen expression is necessary in
therapeutic response monitoring and targeted therapy
guidance. The existence of human epidermal growth factor
receptor 2 (HER2) and the concentration of HER2-positive
CTCs are strong indicators for patient diagnosis, prognosis,
and therapeutic monitoring. Herein we report the direct
isolation of HER2-positive CTCs by peptide-functionalized
nanomaterials. We designed and screened out a peptide as an
HER2 antibody alternative demonstrating high HER2 affinity
and selectivity. This HER2 recognition peptide bound
efficiently with HER2 at the ligand-binding domain. Efficient HER2-positive CTC capture and detection were demonstrated
using magnetic nanoparticles functionalized with the HER2 recognition peptide