Size-Dependent Photoluminescence from Thiolate-Protected Water-Soluble Cobalt Nanoclusters

2020 ◽  
Vol 5 (7) ◽  
pp. 2263-2270
Author(s):  
Murugan Ramadurai ◽  
Packirisamy Vinitha ◽  
Pandurangan Prabhu ◽  
---Shanmugam Komathi ◽  
Rajendran Suresh Babu
Nanomaterials ◽  
2012 ◽  
Vol 2 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Ying Xu ◽  
Najeh Al-Salim ◽  
Richard D. Tilley
Keyword(s):  

2009 ◽  
Vol 9 (14) ◽  
pp. 4841-4854 ◽  
Author(s):  
T. Anttila ◽  
P. Vaattovaara ◽  
M. Komppula ◽  
A.-P. Hyvärinen ◽  
H. Lihavainen ◽  
...  

Abstract. In situ measurements of aerosol water uptake and activation of aerosols into cloud droplets provide information on how aerosols influence the microphysical properties of clouds. Here we present a computational scheme that can be used in connection with such measurements to assess the influence of the particle hygroscopicity and mixing state (in terms of the water uptake) on the cloud nucleating ability of particles. Additionally, it provides an estimate for the peak supersaturation of water vapour reached during the formation of the observed cloud(s). The method was applied in interpreting results of a measurement campaign that focused on aerosol-cloud interactions taking place at a subarctic background site located in Northern Finland (second Pallas Cloud Experiment, 2nd PaCE). A set of case studies was conducted, and the observed activation behavior could be successfully explained by a maximum supersaturation that varied between 0.18 and 0.26% depending on the case. In these cases, the diameter corresponding to the activated fraction of 50% was in the range of 110–140 nm, and the particles were only moderately water soluble with hygroscopic growth factors varying between 1.1 and 1.4. The conducted analysis showed that the activated fractions and the total number of particles acting as CCN are expected to be highly sensitive to the particle hygroscopic growth properties. For example, the latter quantity varied over a factor between 1.8 and 3.1, depending on the case, when the mean hygroscopic growth factors were varied by 10%. Another important conclusion is that size-dependent activation profiles carries information on the mixing state of particles.


2016 ◽  
Vol 8 (5) ◽  
pp. 1060-1068 ◽  
Author(s):  
Aakriti Tyagi ◽  
Kamla Rawat ◽  
Anita K. Verma ◽  
H. B. Bohidar

Water soluble size variable (2.43–5.09 nm) CdSe quantum dots.


2007 ◽  
Vol 1007 ◽  
Author(s):  
Chang Zhong ◽  
Yuping Bao ◽  
Dung M. Vu ◽  
R. Brian Dyer ◽  
Jennifer S. Martinez

ABSTRACTFluorescent metal nanoclusters, which consist of collections of small numbers of noble metal atoms, are of great interest in photochemistry and photophysics due to their strong size-dependent emission. Historically their generation was confined to gaseous and solid phases; however, recently a unique organic/inorganic hybrid materials approach was developed that utilizes dendrimers as templates to protect nanoclusters from solution based fluorescence quenching. These hybrid dendrimer/gold nanoclusters are water-soluble and highly fluorescent. Yet there are several intrinsic deficiencies in their synthetic method: first, NaBH4, a toxic chemical, was used as reducing agent in the reaction; and second, the reaction yield was low due to the concurrent formation of large, non-emissive, gold particles. Here we report a particle-free method to produce dendrimer-encapsulated gold nanoclusters in high-yield. Proof of concept is demonstrated using OH-terminated poly(amidoamine) dendrimer and Au(PX3)3Cl (X = Ph, Me), but the approach can also be extended to the combination of other dendrimers and organic noble metal salts. Our approach yields fluorescent clusters with homogeneous size distribution. These clusters can be transferred to aqueous solution and used directly for biological applications.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Byambajav Lkhagvadulam ◽  
Jung Hwa Kim ◽  
Il Yoon ◽  
Young Key Shim

Gold nanoparticles (GNPs) conjugates of water soluble ionic photosensitizer (PS), purpurin-18-N-methyl-D-glucamine (Pu-18-NMGA), were synthesized using various molar ratios between HAuCl4and Pu-18-NMGA without adding any particular reducing agents and surfactants. The PS-GNPs conjugates showed long wavelength absorption of range 702–762 nm, and their different shapes and diameters depend on the molar ratios used in the synthesis.In vitroanticancer efficacy of the PS-GNPs conjugates was investigated by MTT assay against A549 cells, resulting in higher photodynamic activity than that of the free Pu-18-NMGA. Among the PS-GNPs conjugates, the GNPs conjugate from the molar ratio of 1 : 2 (Au(III): Pu-18-NMGA) exhibits the highest photodynamic activity corresponding to bigger size (~60 nm) of the GNPs conjugate which could efficiently transport the PS into the cells than that of smaller size of the GNPs conjugate.


2019 ◽  
Vol 20 ◽  
pp. 100393 ◽  
Author(s):  
Tanmoy Dutta ◽  
Narendra Nath Ghosh ◽  
Asoke P. Chattopadhyay ◽  
Mahuya Das

2018 ◽  
Vol 20 (6) ◽  
pp. 4563-4570 ◽  
Author(s):  
Michael J. Hartmann ◽  
Jill E. Millstone ◽  
Hannu Häkkinen

Density functional theory calculations show that the collection and distribution of local coordination environments, from both Co–Co and Co–L interactions, in CoNLM nanoclusters determine size dependent magnetic trends.


2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Jeehye Byun ◽  
Hasmukh A. Patel ◽  
Damien Thirion ◽  
Cafer T. Yavuz

Nanoscale ◽  
2014 ◽  
Vol 6 (2) ◽  
pp. 683-687 ◽  
Author(s):  
Nuwan Kothalawala ◽  
James Lee West IV ◽  
Amala Dass
Keyword(s):  

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