Plasmonic metal nanoparticles have unique optical properties, such as localized surface plasmon resonance resulting from the oscillation of free electrons. Integrating discrete plasmonic nanoparticle into assembled nanostructures enables interparticle plasmon coupling and collective properties that are often absent in their discrete counterparts. Synthetic polymers as surface ligands on plasmonic nanoparticles can stabilize the nanoparticles, define the surface properties, control the interparticle interactions and therefore direct the nanoparticle self-assembly. Given the length scale of polymers comparable to the size of plasmonic nanoparticles of interest, polymer ligands are promising for precisely controlling the interparticle interaction. Engineering polymer ligands in the terms of their chemical composition, grafting density, anchoring groups and chain lengths is critical to control the assembly nanostructures and plasmon coupling of adjacent nanoparticles. The focus of this perspective is to identify and address the unmet challenges in the field of polymer-grafted plasmonic nanoparticles (PGNPs). Key unresolved issues broadly covered from the design of PGNP building blocks to their self-assembly are illustrated by highlighting a few examples. In views of more robust building blocks, the choice of inexpensive metals, the new anchoring groups and precision control of polymer ligands are discussed. We further consider the challenges in breaking the surface symmetry of plasmonic nanoparticles and designing synthetic polymers to achieve reversibility and directionality in the self-assembly of PGNPs.

等离子体金属纳米粒子具有独特的光学特性，例如由于自由电子的振荡而导致的局部表面等离子体共振。将离散的等离激元纳米粒子整合到组装的纳米结构中，可以实现粒子间的等离激元耦合和集体特性，而这些特性通常在它们的离散对应物中不存在。等离子体聚合物纳米粒子上作为表面配体的合成聚合物可以稳定纳米粒子，定义表面特性，控制粒子间的相互作用并因此指导纳米粒子的自组装。给定与感兴趣的等离激元纳米粒子的大小相当的聚合物的长度尺度，聚合物配体有望用于精确控制粒子间的相互作用。在化学组成，接枝密度，锚定基团和链长对于控制组装纳米结构和相邻纳米粒子的等离激元耦合至关重要。该观点的重点是确定并解决聚合物接枝等离子体纳米颗粒（PGNP）领域中尚未解决的挑战。通过突出几个示例，说明了从PGNP构建块的设计到其自组装广泛涵盖的关键未解决问题。考虑到更坚固的构件，讨论了廉价金属的选择，新的锚定基团和聚合物配体的精确控制。我们进一步考虑了打破等离激元纳米粒子的表面对称性和设计合成聚合物以实现PGNPs自组装的可逆性和方向性的挑战。