Biotin-functional oligo(p-phenylene vinylene)s synthesized using click chemistry

Using Cu(1)-catalyzed [3+2] Huisgen 'click' cycloaddition, a rigid rod - like oligo(p-phenylene vinylene) (OPV) was functionalized at both ends with biotin ligands, combining the valuable electro-optical properties of conjugated organic molecules with the biological recognition capability of biotin. Biotin can be placed at variable distances from the oligomer via appropriate length of a hydrophilic spacer, which also serves to regulate the binding capabilities of the two terminal biotin units. To demonstrate this binding potential, networks were formed with streptavidin-coated quantum dots. The synthetic conditions are presented, together with representative optimizations of the key reactions. The organic compounds were analyzed by means of ATR/FTIR, 1H NMR (200 or 600 MHz), 13C NMR, 2D NMR (HMBC, HMQC experiments), MS (ESI or MALDI-TOF), and optical spectroscopy. Networks were imaged with TEM.