Functionalisation of gold surfaces via topological templates

Abstract

Regioselectively addressable functionalised templates (RAFT) represent topological cyclic peptides containing orthogonally protected attachment sites pointing to opposite faces of the template backbone. Functionalisation of the template with coordinating groups and alkane chains result in metal-binding and self-association properties in solution without major disruption of the preferred template conformation as inferred by NMR, CD and surface plasmon resonance (SPR) spectroscopy studies. This suggested that the template disposes the appended groups in spatial orientations suitable for their designed functions. Accordingly, a RAFT molecule exhibiting metal-binding sites and thioalkane chains has been incorporated into self-assembled monolayers on gold surfaces and is used to detect external ligand-binding on the surface by SPR spectroscopy. The results demonstrate that RAFT molecules are versatile molecular devices for functionalizing gold surfaces opening a wide range of applications in biosensor technology.