title: Tetrakis(4-sulfonatophenyl)porphyrin-directed assembly of gold nanocrystals: tailoring the plasmon coupling through controllable gap distances.
abstract: It is known that universality and controllability over nanocrystal orientation must be accomplished to facilitate the potential applications of metal nanocrystals in the areas of photonics, electronics, and optics. The facile fabrication of linear chains of Au nanorods and bifurcated junctions of nanorods/nanospheres is achieved via the crosslinking of H-type tetrakis(4-sulfonatophenyl)porphyrin aggregates in solution. The tuning of the plasmon coupling between the Au nanocrystals is demonstrated by varying the porphyrin concentration and thus the interparticle gap distances. Finite-difference time-domain calculations show that the red shift of the plasmon band exhibits a nearly exponential decay with increasing interparticle gap distances, thus giving rise to a "plasmon ruler equation." The gap distances determined according to this equation agree well with the experimental observations and further confirm the porphyrin-directed assembly process. The interaction mechanism between the Au nanorods and porphyrins is further investigated by a biological procedure using the dark-field light scattering technique.
authors: College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors: Li
authors: L
authors: Zhang
authors: Huanjun
authors: H
authors: Chen
authors: Jianfang
authors: J
authors: Wang
authors: Yuan Fang
authors: YF
authors: Li
authors: Jian
authors: J
authors: Wang
authors: You
authors: Y
authors: Sang
authors: Sai Jin
authors: SJ
authors: Xiao
authors: Lei
authors: L
authors: Zhan
authors: Cheng Zhi
authors: CZ
authors: Huang
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D008958:Models, Molecular; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D020349:Surface Plasmon Resonance / Q000379:methods; D013499:Surface Properties
chemical_list: D011108:Polymers; D011166:Porphyrins; C016136:tetraphenylporphine sulfonate; D006046:Gold