Fabrication Of Metallic Micro-/Nano-Structures And Exploitation Of Plasmonic Optical Activity For Chiroptical Sensing

Chirality exists in a variety of living and non-living systems. Unlike the chiral organicmolecules, optical activity of metal nanoparticles can be covered from near UV electronictransition frequency of small size clusters to visible/near-infrared region of the surfaceplasmon frequency of larger size particles. To describe the chiral optical phenomenon ofnano metal materials, two physical models have been developed: collective chiral opticalactivity and individual chiral optical activity. Compared to the chiral phenomenon of singlenano particle which induced by chiral molecular environment, the chiral arrangementnanoparticles of different spatial position or orientation with collective surface plasmonicoptical activity based on molecular self-assembly method, should be novel biosensors withimportant applications.This work is divided into the following two aspects. Firstly, take phospholipid film astemplate, a chiral hybrid superstructure has been achieved from preformed metalnanoparticles. Based on the research of the collective plasmonic chiral optical activity, wedemonstrated that the fabricating chiral superstructures with optical activity responses had avariety of bioscience and biomedicine applications. Take cysteine molecule as an example,different enantiomeric forms can be detected. Secondly, we obtained strongly coupledplasmonic linear structure of gold nanoparticles with enormous feld enhancement, wich isso-called hotspot effect. We achieved high sensitivity detection and quantitative analysis ofsmall chiral molecules based on the chiral optical transfer and amplification effect.This work will provide great potential applications for the artificial nano/micro structurein fields of materials, life, information, etc.