报 告 人：1.Prof.Jeremy Baumburg & 2.Pro. ren Scherman，University of Cambridge

题     目：1.Watching and controlling single molecules in nm-scale plasmonic cavities 

                  2.Functional materials: Exploiting dynamic self-assembly at interfaces

时     间：2016年04月05日（星期二） 

地     点：国家纳米科学中心

邀 请 人：魏志祥 研究员

报告内容：

1.Watching and controlling single molecules in nm-scale plasmonic cavities

Coupling between plasmonic nano-components generates strongly red-shifted resonances combined with intense local field amplification on the nanoscale. This allows directly seeing molecules as well as excitations in semiconductors. We have recently explored plasmonic coupling which can be tuned dynamically, through reliable bottom-up self-assembly. The crucial aspect of these systems is the extreme sensitivity to separation, and how quantum tunneling starts to be directly seen at room temperature in ambient conditions. We recently demonstrated how quantum plasmonics controls the very smallest space that light can be squeezed into.

We also demonstrate the possibility to track few molecules using the extreme enhancements. We show how the new generation of 2D semiconductors can couple to such nano-scale gaps utilizes our nanoparticle on mirror geometry. We find that changing just a single atom on each molecule of a self-assembled monolayer can shift the plasmon by over 50nm, and produce surprising vibrational signatures. These have encouraging prospective applications in (bio)molecular sensing as well as fundamental science. We also now demonstrate strong coupling with single molecules in appropriately designed optical and molecular nano-structures. The ability to track and watch molecules interact and react opens up the ability to study chemistry molecule-by-molecule and potentially to control single reaction pathways.

2.Functional materials: Exploiting dynamic self-assembly at interfaces

We are interested in the development of controlled polymer architectures, hybrid nanoparticle-soft matter assemblies and the integration of dynamic supramolecular systems at interfaces. Current research projects in the group include the application of macrocyclic host-guest chemistry using cucurbit[n]urils in the development of novel microcapsules, supramolecular hydrogels, drug-delivery systems based on dynamic hydrogels, adhesion between a variety of surfaces, the conservation and restoration of important historical artefacts1a through the exploitation of supramolecular polymer chemistry and sensing and catalysis using self-assembled nanophotonic systems.

 Modification of solution viscosity using multivalent polymers has been accomplished through dynamic cross-linking in water using CB[8]. These hydrogels, with extremely high water content (up to 99.75% water by weight), have also been prepared by utilising renewable cellulose derivatives. Their rapid formation1b and shear-induced flow properties make these materials perfectly suited for use as injectable hydrogels for delivery of therapeutics.

 Polymer-inorganic composite materials can be readily prepared based on the CB[8] coupling of multivalent gold nanoparticles (AuNPs) to functional copolymers. When these systems are attached onto gold surfaces intricate control is achieved over the site-selective immobilisation of colloids and peptides. This has great scope for the development of optical materials, chemical sensors2 and biological separations. Additionally, we have developed an innovative new technique for manufacturing 'smart' microcapsules in large quantities using continuous flow in a single step from tiny droplets of water.3a The major advantage of this manufacturing platform over current methods is that a variety of cargos can be efficiently loaded during the microcapsule formation at room temperature, and the dynamic supramolecular interactions provide control over the porosity of the capsules and the timed release of their contents using stimuli.3b Our CB[n] based host-guest systems exhibit dynamic self assembly and are capable of responding to stimuli (photochemical, chemical, and thermal) allowing for external control and function to be built into the materials.

欢迎感兴趣的老师、同学参加！