scholarly journals Tuning the Optical Properties of Au Nanoclusters by Designed Proteins

2021 ◽  
pp. 2101332
Author(s):  
Elena Lopez‐Martinez ◽  
Diego Gianolio ◽  
Saül Garcia‐Orrit ◽  
Victor Vega‐Mayoral ◽  
Juan Cabanillas‐Gonzalez ◽  
...  
2011 ◽  
Vol 115 (49) ◽  
pp. 24085-24091 ◽  
Author(s):  
Giovanni Barcaro ◽  
Michel Broyer ◽  
Nicola Durante ◽  
Alessandro Fortunelli ◽  
Mauro Stener

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 110 ◽  
Author(s):  
Antonio Aires ◽  
Elena Lopez-Martinez ◽  
Aitziber Cortajarena

Among all new nanomaterials, metal nanoclusters (NCs) have attracted special attention due to their interesting optical properties, among others. Metal NCs have been recently studied and used as sensors for different analytes. However, there is a need to explore the potential of these new sensors in a systematic manner and to develop new systems to broaden the possibilities that sensing offers to the industry. In this work, we show the potential use of repeat protein scaffolds as versatile templates for the synthesis and stabilization of various metal NCs, specifically Au, Ag, and CuNCs. The resulting protein-metal NCs hybrids are evaluated as sensors for different stimuli such as temperature, ions, or reactive oxygen species (ROS). Among the three protein-metal NCs, all performed nicely as temperature sensors, AuNCs responded to metal ions, and AgNCs were able to detect ROS.


2016 ◽  
Vol 56 (1) ◽  
Author(s):  
Vilius Poderys ◽  
Marija Matulionytė-Safinė ◽  
Dainius Rupšys ◽  
Ričardas Rotomskis

Bovine serum albumin stabilized gold nanoclusters (BSA-Au nanoclusters) have been widely studied due to their possible applications in biomedicine as sensors, fluorescent or multi-modality markers, and therapeutic agents. Synthesis and optical properties of these nanoclusters have been extensively investigated; however, there is still very little data on photostability of BSA-Au nanoclusters. Photostability of BSA-Au nanoclusters is of major importance for a variety of applications, such as material sensing and fluorescence imaging. Herein we demonstrate that after synthesis the BSA-Au solution has two photoluminescence (PL) bands peaking at 468 and 660 nm. Nevertheless, a different behaviour of the PL bands at 468 and 660 nm upon irradiation indicates that only band at 660 nm is related to PL of Au nanoclusters. BSA-Au nanoclusters exhibit great colloidal stability and do not undergo irreversible changes when heated up to 65 °C. However, irradiation of BSA-Au nanoclusters causes a wavelength dependent decrease of intensity and a hypsochromic shift of the PL band at 660 nm which is proportional to the delivered dose. The shift of the PL band at 660 nm could occur due to loss of several gold atoms in Au nanoclusters and/or due to deterioration of a nanoparticle coating layer. We have also demonstrated that the photostability of BSA-Au nanoclusters increases in the cell growth medium.


2008 ◽  
Vol 205 (11) ◽  
pp. 2635-2638 ◽  
Author(s):  
K. Iliopoulos ◽  
D. Athanasiou ◽  
A. Meristoudi ◽  
N. Vainos ◽  
S. Pispas ◽  
...  

2016 ◽  
Vol 52 (30) ◽  
pp. 5234-5237 ◽  
Author(s):  
Xun Yuan ◽  
Nirmal Goswami ◽  
Weiliang Chen ◽  
Qiaofeng Yao ◽  
Jianping Xie

Ligand shell engineering of Au nanoclusters could induce their structural distortions for generating interesting optical properties.


2011 ◽  
Vol 115 (14) ◽  
pp. 6277-6282 ◽  
Author(s):  
Nicola Durante ◽  
Alessandro Fortunelli ◽  
Michel Broyer ◽  
Mauro Stener

Author(s):  
K. Tsuno ◽  
T. Honda ◽  
Y. Harada ◽  
M. Naruse

Developement of computer technology provides much improvements on electron microscopy, such as simulation of images, reconstruction of images and automatic controll of microscopes (auto-focussing and auto-correction of astigmatism) and design of electron microscope lenses by using a finite element method (FEM). In this investigation, procedures for simulating the optical properties of objective lenses of HREM and the characteristics of the new lens for HREM at 200 kV are described.The process for designing the objective lens is divided into three stages. Stage 1 is the process for estimating the optical properties of the lens. Firstly, calculation by FEM is made for simulating the axial magnetic field distributions Bzc of the lens. Secondly, electron ray trajectory is numerically calculated by using Bzc. And lastly, using Bzc and ray trajectory, spherical and chromatic aberration coefficients Cs and Cc are numerically calculated. Above calculations are repeated by changing the shape of lens until! to find an optimum aberration coefficients.


Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).


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