Fig. 3

Selection of M13 phage clones with Cu (II)-binding peptides. a Identification of M13 phages selective to Cu (II) ions in ELISA assay. Functionalyzied and modified with Cu (II) ions microtiter plate were incubated with 100 µL of 10⁹ PFU selected clones per well. Nonbounded phages were discarded and plate was washed 10 times. For phage elution 100 µL of 0.2 M Glycine–HCl (pH 2.2) was used. Eluted phages were titered according to the method described in The Ph.D.™-7 Phage Display Peptide Library Kit manual. Binding specificity is presented as the phage titer eluted from wells coated with Cu metal ions. Three independent experiments were conducted and the mean is presented. PFU plaque-forming unit. b Representation of peptides sequences with the highest affinity to copper ions