Peptide-Guided\nAssembly of Silver Nanoparticles for\nthe Diagnosis of HER2-Positive Breast Cancer

Peptide-engineered nanoparticles have great potential\nfor biomedical\nresearch and application. In this work, we have designed and fabricated\nan electrochemical biosensor based on peptide-guided assembly of silver\nnanoparticles (AgNPs), in which a peptide is endowed with dual functions\nto recognize target and guide assembly of AgNPs. As a proof of concept,\nthe performance of this biosensor is validated by quantifying human\nepidermal growth factor receptor 2 (HER2) protein. In detail, the\nend of the HER2-specific binding peptide is grafted with a positively\ncharged peptide, which can guide the orderly assembly of AgNPs, while\nelectrochemical signals can be obtained through phosphine-silver coordination.\nUsing this electrochemical biosensor, HER2 protein can be quantified\nwith high sensitivity and specificity, and the limit of detection\ncan be as low as 0.05 pg/mL. Moreover, the antifouling electrode surface\nprepared by the modification of a layer of antifouling zwitterionic\npeptide allows this biosensor to be used for the detection of serum\nHER2 protein from breast cancer patients, which provides the clear\nevidence for the distinction of HER2+ breast cancer patients and HER2-\nbreast cancer patients.