Phage display – a new tool for the recovery of critical elements from primary and secondary sources

The development of effective and ecofriendly processes for the recovery of critical elements poses a challenge for scientists all over the world. Beside the relevance for the environment new products and techniques have to be highly specific for target materials and be economically applicable. Critical elements such as rare earth elements are part of a multitude of modern electronic devices. However, their recycling rate is low partly due to the similar chemical and physical properties of the elements making their separation difficult.
To generate highly specific peptides that bind specifically to individual elements of interest, the phage surface display (PSD) technology was used. PSD technology was originally developed to identify peptides with high binding specificity for biological molecules such as viruses, antibodies or fusion proteins. Later the technology was successfully applied for inorganic targets as well.
In the current project four different fluorescent phosphor components were used to identify a small number of specific binding peptides via PSD. The newly identified peptides differ strongly in their amino acid composition and binding behavior. Binding properties can be improved by substitution of individual amino acids by more effective amino acids. The application of peptides in bioflotation processes is now being tested as an efficient separation process for rare earth minerals.
In summary, phage surface display is a promising tool for the development of highly specific binding peptides. The development of ecofriendly material specific collectors in bioflotation and separation processes has the potential to revolutionize traditional recycling techniques.