Germanium Plasmon Enhanced Resonators for Label-Free Terahertz Protein Sensing

Abstract A Terahertz protein sensing concept based on subwavelength Ge resonators is presented. Ge bowtie resonators, compatible with CMOS fabrication technology, have been designed and characterized with a resonance frequency of 0.5 THz and calculated local intensity enhancement of 10.000. Selective biofunctionalization of Ge resonators on Si wafer was achieved in one step using lipoic acid-HaloTag ligand (LA-HTL) for biofunctionalization and passivation. The results lay the foundation for future investigation of protein tertiary structure and the dynamics of protein hydration shell in response to protein conformation changes.

Download Full-text

Droplet Factories: Synthesis and Assembly of Silver and Palladium Nanoparticles at the Liquid-Liquid Interface

10.26434/chemrxiv.10288556 ◽

2019 ◽

Author(s):

Suchanuch Sachdev ◽

Rhushabh Maugi ◽

Sam Davis ◽

Scott Doak ◽

Zhaoxia Zhou ◽

...

Keyword(s):

Iron Oxide ◽

Reaction Rate ◽

Tertiary Structure ◽

Flow Reactor ◽

Pd Nanoparticles ◽

Subsequent Removal ◽

Immiscible Liquids ◽

Flow Reactors ◽

Droplet Flow ◽

One Step

<div>The interface between two immiscible liquids represent an ideal substrate for the assembly of nanomaterials. The defect free surface provides a reproducible support for creating densely packed ordered materials. Here a droplet flow reactor is presented for the synthesis and/ or assembly of nanomaterials at the interface of the emulsion. Each droplet acts as microreactor for a reaction between decamethylferrocene (DmFc) within the hexane and metal salts (Ag+/ Pd2+) in the aqueous phase. The hypothesis was that a spontaneous, interfacial reaction would lead to the assembly of nanomaterials creating a Pickering emulsion. The subsequent removal of the solvents showed how the Ag nanoparticles were trapped at the interface and retain the shape of the droplet, however the Pd nanoparticles were dispersed with no tertiary structure. To further exploit this, a one-step process where the particles are synthesised and then assembled into core-shell materials was proposed. The same reactions were performed in the presence of oleic acid stabilise Iron oxide nanoparticles dispersed within the hexane. It was shown that by changing the reaction rate and ratio between palladium and iron oxide a continuous coating of palladium onto iron oxide microspheres can be created. The same reaction with silver, was unsuccessful and resulted in the silver particles being shed into solution, or incorporated within the iron oxide micro particle. These insights offer a new method and chemistry within flow reactors for the creation of palladium and silver nanoparticles. We use the technique to create metal coated iron oxide nanomaterials but the methodology could be easily transferred to the assembly of other materials.</div><div><br></div>

Download Full-text

One-step fast and label-free imaging array for multiplexed detection of trace avian influenza viruses

Analytica Chimica Acta ◽

10.1016/j.aca.2021.338645 ◽

2021 ◽

pp. 338645

Author(s):

Dagang Jiang ◽

Yafei Tian ◽

Yujiao Zhang ◽

Xueyun Lu ◽

Dan Xiao ◽

...

Keyword(s):

Avian Influenza ◽

Influenza Viruses ◽

Label Free ◽

Avian Influenza Viruses ◽

Multiplexed Detection ◽

Imaging Array ◽

One Step

Download Full-text

One-step and label-free detection of alpha-fetoprotein based on aggregation of gold nanorods

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2012.04.091 ◽

2012 ◽

Vol 175 ◽

pp. 194-200 ◽

Cited By ~ 20

Author(s):

Xia Xu ◽

Yibin Ying ◽

Yanbin Li

Keyword(s):

Gold Nanorods ◽

Alpha Fetoprotein ◽

Label Free ◽

Label Free Detection ◽

One Step

Download Full-text

One-step hydrothermal synthesis of down/up-conversion luminescence F-doped carbon quantum dots for label-free detection of Fe3+

Microchemical Journal ◽

10.1016/j.microc.2019.104217 ◽

2019 ◽

Vol 151 ◽

pp. 104217 ◽

Cited By ~ 4

Author(s):

Dan Hong ◽

Xiaoyan Deng ◽

Jiaman Liang ◽

Jiayu Li ◽

Yi Tao ◽

...

Keyword(s):

Quantum Dots ◽

Hydrothermal Synthesis ◽

Carbon Quantum Dots ◽

Label Free ◽

Label Free Detection ◽

One Step

Download Full-text

Length-scale dependence of protein hydration-shell density

Physical Chemistry Chemical Physics ◽

10.1039/c9cp06214a ◽

2020 ◽

Vol 22 (14) ◽

pp. 7340-7347

Author(s):

Akash Deep Biswas ◽

Vincenzo Barone ◽

Andrea Amadei ◽

Isabella Daidone

Keyword(s):

Hydration Shell ◽

Scale Dependence ◽

Protein Hydration ◽

Length Scale ◽

Protein Size ◽

Protein Hydration Shell

An increase in protein hydration-shell density relative to that of the bulk is observed (in the range of 4–14%) for all studied proteins and this density-increment, which decreases for decreasing protein size, is caused by the protein size only.

Download Full-text