Hierarchical assembly of gold nanorods stripe patterns for sensing and cells alignment.

Abstract

Hierarchical assemblies of nano-material superstructure with controlled orientation affords a multitude of novel properties of plasmonics and broadly applications. Yet constructing multi-functional superstructures with positioning nanoparticles in desired locations remain challenges. Herein, gold nanorods (GNRs) assembled in stripe patterns with controlled orientation and structures in millimetre scale for versatile application are achieved. Applications of patterned GNRs in sensing enhancement and engineering mammalian cells alignment are investigated experimentally. The performance of patterned GNRs in surface enhanced Raman scattering (SERS) and electrical sensing are found in orientational dependence. The SERS signals of vertically arranged GNRs arrays exhibit double folder intensity than horizontally arranged. In contrast, the horizontally arranged GNRs exhibit twice high electrical conductivity. The system is further explored to pattern mammalian cells, for the first time, we reveal nanostructured topography of GNRs confine cells to specific region, direct the adhesion and extension of living cells, which open up a broad application in tissue engineering and biosensing.