Figure 1.

Scheme of DARPin-BSA-GNR synthesis. 1: Coating of a GNR (light brown) with BSA (grey) molecules. 2: Modification of primary amino groups of BSA molecules in the coating layer by Traut’s reagent. This reaction introduces SH groups (shown in yellow) into proteins. 3: Attachment of sulfo-EMCS to one of the primary amino groups of the DARPin (shown in aqua). 4: Covalent attachment of the sulpho-EMCS-modified DARPin molecules to SH groups of the Traut-reagent-treated BSA-coated GNR.