Highly parallel nano-synthesis of cleavable peptide-dye conjugates on cellulose membranes

Treatment of mercapto-functionalized cellulose membranes with preformed Fmoc-amino acid 3-bromopropyl esters yielded membrane-bound amino acids connected via a stable thioether and a cleavable ester bond. This synthesis strategy allows the highly parallel preparation of peptides that can be solubilized from the solid support. We apply this approach to the synthesis of novel peptide–cyanine dye conjugates which are potentially useful as fluorescent contrast agents targeted to tumor-specific receptors.