College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Small. 2010 Sep 20;6(18):2001-9. doi: 10.1002/smll.201000354.
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.
众所周知，为了促进金属纳米晶体在光子学、电子学和光学领域的潜在应用，必须实现对纳米晶体取向的普遍性和可控性。通过在溶液中交联 H 型四(4-磺酸钠苯基)卟啉聚集体，实现了 Au 纳米棒的线性链和纳米棒/纳米球分叉结的简便制造。通过改变卟啉浓度从而改变粒子间的间隙距离，演示了 Au 纳米晶体之间的等离子体耦合的调谐。有限差分时域计算表明，等离子体带的红移随粒子间间隙距离的增加呈近指数衰减，从而产生“等离子体标尺方程”。根据该方程确定的间隙距离与实验观察结果吻合良好，进一步证实了卟啉导向组装过程。通过使用暗场光散射技术的生物程序进一步研究了 Au 纳米棒和卟啉之间的相互作用机制。
