Cui Jiabin, Koley Somnath, Panfil Yossef E, Levi Adar, Waiskopf Nir, Remennik Sergei, Oded Meirav, Banin Uri
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
Angew Chem Int Ed Engl. 2021 Jun 21;60(26):14467-14472. doi: 10.1002/anie.202101155. Epub 2021 May 19.
Top-down fabricated nanoantenna architectures of both metallic and dielectric materials show powerful functionalities for Raman and fluorescence enhancement with relevance to single molecule sensing while inducing directionality of chromophore emission with implications for single photon sources. We synthesize the smallest bow-tie nanoantenna by selective tip-to-tip fusion of two tetrahedral colloidal quantum dots (CQDs) forming a dimer. While the tetrahedral monomers emit non-polarized light, the bow-tie architecture manifests nanoantenna functionality of enhanced emission polarization along the bow-tie axis, as predicted theoretically and revealed by single-particle spectroscopy. Theory also predicts the formation of an electric-field hotspot at the bow-tie epicenter. This is utilized for selective light-induced photocatalytic metal growth at that location, unlike growth on the free tips in dark conditions, thus demonstrating bow-tie dimer functionality as a photochemical reaction center.
由金属和介电材料通过自上而下制造的纳米天线结构，在与单分子传感相关的拉曼和荧光增强方面显示出强大的功能，同时诱导发色团发射的方向性，这对单光子源具有重要意义。我们通过将两个四面体胶体量子点（CQD）进行选择性的尖端对尖端融合形成二聚体，合成了最小的蝴蝶结形纳米天线。虽然四面体单体发射非偏振光，但正如理论预测并通过单粒子光谱揭示的那样，蝴蝶结形结构表现出沿蝴蝶结轴增强发射偏振的纳米天线功能。理论还预测在蝴蝶结形中心会形成一个电场热点。与在黑暗条件下在自由尖端上的生长不同，这被用于在该位置进行选择性光诱导的光催化金属生长，从而证明蝴蝶结形二聚体作为光化学反应中心的功能。
