scholarly journals Hotspot generation for unique identification with nanomaterials

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nema M. Abdelazim ◽  
Matthew J. Fong ◽  
Thomas McGrath ◽  
Christopher S. Woodhead ◽  
Furat Al-Saymari ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Gold Nanoparticles ◽  
Optical Measurement ◽  
Far Field ◽  
Au Nps ◽  
Coated Substrate ◽  
Local Arrangement ◽  
Practical Challenge ◽  
Dependent Interaction ◽  
Physical Complexity

AbstractNanoscale variations in the structure and composition of an object are an enticing basis for verifying its identity, due to the physical complexity of attempting to reproduce such a system. The biggest practical challenge for nanoscale authentication lies in producing a system that can be assessed with a facile measurement. Here, a system is presented in which InP/ZnS quantum dots (QDs) are randomly distributed on a surface of an aluminium-coated substrate with gold nanoparticles (Au NPs). Variations in the local arrangement of the QDs and NPs is shown to lead to interactions between them, which can suppress or enhance fluorescence from the QDs. This position-dependent interaction can be mapped, allowing intensity, emission dynamics, and/or wavelength variations to be used to uniquely identify a specific sample at the nanoscale with a far-field optical measurement. This demonstration could pave the way to producing robust anti-counterfeiting devices.

scholarly journals The Physical Properties and Applications of Gold Nanoparticles (Au NPs): Review

2021 ◽  
Vol 3 (1) ◽  
pp. 74-86
Author(s):  
Rusul Adnan Al-wardy . ◽  
Saad Khalid Rahi .
Keyword(s):  
Drug Delivery ◽  
Quantum Dots ◽  
Gold Nanoparticles ◽  
Physical Properties ◽  
Current Work ◽  
Spherical Nanoparticles ◽  
Au Nps ◽  
3 Dimensional ◽  
Nano Rods ◽  
Catalytic Applications

Nanoparticles of gold that for years have been recognized are the concept of an increasingly rising reports number and of promising for electronic, optical, magnetic, biomedical and catalytic applications in century of 21st. Because of Nanoparticles of gold stability, an interest in such research is a reason for performing the current work. There are various types of AuNPs: Zero-dimensional AuNps: quantum dots, spherical nanoparticles. AuNPs as 1-dimensional: nanowires, nano-rods, nano-belts, nanotubes. AuNPs as 2-dimensional: nano-plates of gold, nano-shell and, AuNPs as 3 dimensional: nano tadpoles of gold, nano- dumbbells of gold (AuNDs), AuNPs being spread, for example, nano-dendrites of gold, nano-pods, and nano-stars. Au NPs, in the field of medicine are investigated for several applications include vectors of drug delivery, agents of contrast, and therapy of localized heat, biomarkers of ultra-sensitive and more. AuNPs are very attractive material for biosensor, chemosensory, genosensor and immunosensor production

Multifunctional far-field luminescence nanoscope for studying single molecules and quantum dots

2018 ◽  
Vol 189 (03) ◽  
pp. 312-322 ◽  
Author(s):  
Ivan Yu. Eremchev ◽  
M.Yu. Eremchev ◽  
Andrei V. Naumov
Keyword(s):  
Quantum Dots ◽  
Single Molecules ◽  
Far Field

scholarly journals Easy and fast in-situ functionalization of exfoliated 2D black phosphorus with gold nanoparticles

2021 ◽  
Author(s):  
Salvatore Moschetto ◽  
Andrea Ienco ◽  
Gabriele Manca ◽  
Manuel Serrano-Ruiz ◽  
Maurizio Peruzzini ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Black Phosphorus ◽  
Au Nps ◽  
In Situ Functionalization

Heterostructures of single- and few-layer black phosphorus (2D bP) functionalized with gold nanoparticles (Au NPs) have been recently reported in the literature, exploiting their intriguing properties and biocompatibility for catalytic,...

scholarly journals Continuous citrate‐capped gold nanoparticle synthesis in a two‐phase flow reactor

2021 ◽  
Author(s):  
Spyridon Damilos ◽  
Ioannis Alissandratos ◽  
Luca Panariello ◽  
Anand N. P. Radhakrishnan ◽  
Enhong Cao ◽  
...  
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Residence Time ◽  
Flow Reactor ◽  
Phase Flow ◽  
Continuous Manufacturing ◽  
Two Phase ◽  
Process Yield ◽  
Au Nps ◽  
Manufacturing Platform

AbstractA continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10–20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 oC and 2.3 bar(a) pressure. The use of a two-phase flow system – using heptane as the continuous phase – prevented fouling on the reactor walls, while improving the residence time distribution. Continuous syntheses for up to 2 h demonstrated its potential application for continuous manufacturing, while live quality control was established using online UV-Vis photospectrometry that monitored the particle size and process yield. The synthesis was stable and reproducible over time for gold precursor concentration above 0.23 mM (after mixing), resulting in average particle size between 12 and 15 nm. A hydrophobic membrane separator provided successful separation of the aqueous and organic phases and collection of colloidal Au NPs in flow. Process yield increased at higher inlet flow rates (from 70 % to almost 100 %), due to lower residence time of the colloidal solution in the separator resulting in less fouling in the PTFE membrane. This study addresses the challenges for the translation of the synthesis from batch to flow and provides tools for the development of a continuous manufacturing platform for gold nanoparticles.Graphical abstract

Macroscopical monolayer films of ordered arrays of gold nanoparticles as SERS substrates for in-situ quantitative detection in aqueous solutions

Nanoscale ◽  
2021 ◽  
Author(s):  
Lixiang Xing ◽  
Cui Wang ◽  
Yi Cao ◽  
Jihui Zhang ◽  
Haibing Xia
Keyword(s):  
Gold Nanoparticles ◽  
Volume Fraction ◽  
Water Volume ◽  
Quantitative Detection ◽  
Monolayer Films ◽  
Au Nps ◽  
Sers Substrates ◽  
Ordered Arrays ◽  
Water Volume Fraction

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of...

scholarly journals Effects of Different Surfactant Charges on the Formation of Gold Nanoparticles by the LASiS Method

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2937
Author(s):  
Muhammad Zulfajri ◽  
Wei-Jie Huang ◽  
Genin-Gary Huang ◽  
Hui-Fen Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Laser System ◽  
Synthesis Process ◽  
Au Nps ◽  
Laser Fluences ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
532 Nm

The laser ablation synthesis in solution (LASiS) method has been widely utilized due to its significant prospects in laser microprocessing of nanomaterials. In this study, the LASiS method with the addition of different surfactant charges (cationic CTAB, nonionic TX-100, and anionic SDS) was used to produce Au NPs. An Nd:YAG laser system at 532 nm excitation with some synthetic parameters, including different laser fluences, ablation times, and surfactant concentrations was performed. The obtained Au NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, and zeta potential analyzer. The Au NPs exhibited the maximum absorption peak at around 520 nm for all samples. The color of Au NPs was changed from red to reddish by increasing the laser fluence. The surfactant charges also played different roles in the Au NPs’ growth during the synthesis process. The average sizes of Au NPs were found to be 8.5 nm, 5.5 nm, and 15.5 nm with the medium containing CTAB, TX-100, and SDS, respectively. Besides, the different surfactant charges induced different performances to protect Au NPs from agglomeration. Overall, the SDS and CTAB surfactants exhibited higher stability of the Au NPs compared to the Au NPs with TX-100 surfactant.

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