Hybrid Gold-Nanoparticle-Cored Conjugated Thiophene Dendrimers: Synthesis, Characterization, and Energy-Transfer Studies

• Published in: Chemistry : a European journal 2011-08, Vol.17 (32), p.8929-8940
• Main Authors: Deng, Suxiang, Fulghum, Timothy M., Krueger, Greg, Patton, Derek, Park, Jin-Young, Advincula, Rigoberto C.
• Format: Article
• Language: English
• Subjects: Chemistry; dendrimers; Dendrimers - chemical synthesis; Dendrimers - chemistry; emission; Energy Transfer; Gold - chemistry; hybrids; Ligands; Magnetic Resonance Spectroscopy; Metal Nanoparticles - chemistry; Nanoparticles; Spectrometry, Fluorescence; Thiophenes - chemical synthesis; Thiophenes - chemistry
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201100246

A series of hybrid Au‐nanoparticle‐dendrimer materials: nanoparticle‐cored thiophene dendrimers (NCTDs) were synthesized, characterized, and investigated for their energy‐transfer properties. These hybrid nanoparticles were obtained by the simultaneous and in situ reduction of gold(III) chloride and self‐assembly of the thiol‐containing thiophene dendritic ligands. The dendron ligands were radially attached to the gold nanoparticles and were analyzed by TEM, UV/Vis, 1H NMR, and FTIR spectroscopies. The solution fluorescence of the attached thiophene dendrons are quenched progressively. Both alkyl‐chain length and dendron size have significant influence on the energy‐transfer efficiency, as well as on core sizes and size distribution of the Au nanoparticles. In spite of the phenomenon’s dependence on nanoparticle size, the energy transfer generally follows the 1/d2 distance dependence. Single NCTD nanoparticles were also adsorbed on highly ordered pyrolytic graphite (HOPG) and uniform aggregates were observed on mica flat substrates. A series of nanoparticle‐cored thiophene dendrimers (see picture) were synthesized, characterized, and investigated for their energy‐transfer properties. The solution fluorescence of the attached thiophene dendrons is quenched progressively. Both alkyl‐chain length and dendron size have a significant influence on the energy‐transfer efficiency, as well as on core sizes and size distribution of the Au nanoparticles.