An Ultra-Selective and Sensitive Fluorescent Chemosensor based on Phage Display Derived Peptide with N-Terminal Cu(II)-Binding Motif

Copper, along with gold, was among the first metals that humans employed. Thus, copper pol-lution of the world's water resources is escalating, posing a significant threat to human health and aquatic ecosystems. It is crucial to develop a detection technology that is both low-cost and fea-sible, as well as ultra-selective and sensitive. This study explores the use of the NH2-Xxx-His motif-derived peptide from phage display technology for ultra-selective Cu2+ detection. Various Cu-binding M13 phage clones were isolated, and their affinity and cross-reactivity for different metal ions were determined. A detailed analysis of the amino acid sequence of the unique Cu-binding peptides was employed. For the development of an optical chemosensor, a peptide with an NH2-Xxx-His motif was selected. The dansyl group was incorporated during solid phase peptide synthesis, and fluorescence detection assays were employed. The efficacy of the Cu2+-binding peptide was verified through spectroscopic measurements. In summary, we de-veloped a highly selective and sensitive fluorescent chemosensor for Cu2+ detection based on a peptide sequence from phage display library that carries the N-terminal Xxx-His motif.