南洋理工大学Ling Xing Yi教授学术报告

报告题目: Plasmonic Nanoparticle Colloidosomes for SERS-based Stand-off Airborne Molecule Detection

报告人：Ling Xing Yi, Professor of School of Physical and Mathematical Sciences, Nanyang Technological University

报告时间：2019年6月20日 上午10:00

地点：大学城校区理六-220

邀请人：姜小芳

报告摘要：

In this talk, I will discuss our group’s development using highly flexible plasmonic colloidosomes as pico-liter analytical sensors. By using the ultrasensitive surface-enhanced Raman scattering (SERS) capability imparted by the plasmonic shell of the Ag nanoparticles of the colloidosomes, the colloidosomes are capable of quantitative examination of multiple analyte(s), even at trace level. Simultaneous two-phase analyte detection at the interfacial of aqueous and organic solvents can also be achieved using our marble. We extend the usage of our flexible colloidosomes as picoreactor, which is also capable of providing in-situ identification of reaction dynamics in their native reaction environment and at molecular level.

Recently, we aerosolize our plasmonic colloidosomes as “airborne plasmonic hotspots” for direct in‐air SERS measurements. The aerosolized plasmonic colloidosomes function as a macroscale 3D and omnidirectional plasmonic cloud that receives laser irradiation and emits signals in all directions. Importantly, it brings about an effective plasmonic hotspot in a length scale of approximately 2.3 cm, which affords 100‐fold higher tolerance to laser misalignment along the z‐axis compared with 2D SERS substrates. APCs exhibit an extraordinary omnidirectional property and demonstrate consistent SERS performance that is independent of the laser and analyte introductory pathway. Furthermore, the first in‐air SERS detection is demonstrated in stand‐off conditions at a distance of 200 cm, highlighting the applicability of 3D omnidirectional plasmonic clouds for remote airborne sensing in threatening or inaccessible areas.

南洋理工大学Lee Yih Hong博士学术报告

报告题目: Controlling the Self-assembly of Plasmonic Metacrystals for SERS Applications

报告人：Lee Yih Hong, Senior Research Fellow of School of Physical and Mathematical Sciences, Nanyang Technological University,

报告时间：2019年6月20日 上午10:50

地点：大学城校区理六-220

邀请人：姜小芳

报告摘要：

In this talk, I will share our research on the concept of ‘one nanoparticle, multiple plasmonic metacrystals’ using a family of Ag polyhedra. Even though it is well-known that shape-controlled nanoparticles can be assembled into structurally diverse superlattices, it remains challenging to control the organization of one nanoparticle morphology into multiple superlattices over large areas. To achieve our concept, we tailor the nanoscale surface wettability of the Ag octahedra [1] and nanocubes [2,3] using a family of thiol-terminated molecules. Subsequent assembly of these nanoparticles at the oil/water interface gives rise to multiple plasmonic metacrystals. Increasing the surface hydrophobicity of the nanoparticle surfaces leads to increasingly open metacrystals with packing densities as low as 24 %. At this packing density, the nanoparticles are standing on their vertices in their respective plasmonic metacrystals. Notably, we can achieve large areas of these plasmonic metacrystals despite their structural instability. A structure-to-function characterization for these metacrystals shows that the lowest packing density metacrystals generates the highest surface-enhanced Raman scattering (SERS) enhancement factors for both the metacrystals of nanocubes and octahedra. Numerical simulations indicate that this strong enhancement arises from the large-area field delocalization within the metacrystals. Our findings here indicate the importance of crystal design in creating efficient SERS substrates. Furthermore, our findings imply that packing the highest number of nanoparticles within a given area will not always generate the strongest SERS enhancement.

新加坡科学研究院Phang In Yee博士学术报告

报告题目: Shape-shifting responsive materials using two photon lithography

报告人：Phang In Yee , Associate researcher of Institute of Materials Research and Engineering, Agency for Science, Technology and Research

报告时间：2019年6月20日 上午11:30

地点：大学城校区理六-220

邀请人：姜小芳

报告摘要：

In this seminar, we present the fabrication of shape-changing 3D protein hydrogel microstructures are fabricated with dynamic, quantitative, directional, and angle-resolved bending via two-photon photolithography[1-2]. We will present a new form of geometrical shape-shifting protein hydrogel microstructures to achieve circle-to-polygon and polygon-to-circle geometrical transformations.