scholarly journals Origin of the Photoluminescence of Metal Nanoclusters: From Metal-Centered Emission to Ligand-Centered Emission

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 261 ◽  
Author(s):  
Tai-Qun Yang ◽  
Bo Peng ◽  
Bing-Qian Shan ◽  
Yu-Xin Zong ◽  
Jin-Gang Jiang ◽  
...  
Keyword(s):  
Quantum Confinement ◽  
Stokes Shift ◽  
Pure Metal ◽  
Luminescent Materials ◽  
Metal Nanoclusters ◽  
Practical Application ◽  
New Class ◽  
Good Biocompatibility ◽  
Luminescent Mechanism ◽  
Metal Charge Transfer

Recently, metal nanoclusters (MNCs) emerged as a new class of luminescent materials and have attracted tremendous interest in the area of luminescence-related applications due to their excellent luminous properties (good photostability, large Stokes shift) and inherent good biocompatibility. However, the origin of photoluminescence (PL) of MNCs is still not fully understood, which has limited their practical application. In this mini-review, focusing on the origin of the photoemission emission of MNCs, we simply review the evolution of luminescent mechanism models of MNCs, from the pure metal-centered quantum confinement mechanics to ligand-centered p band intermediate state (PBIS) model via a transitional ligand-to-metal charge transfer (LMCT or LMMCT) mechanism as a compromise model.

A New Strategy to Construct Gold Nanoclusters-Based Optical Probe Using Luminescence Resonance Energy Transfer

2021 ◽  
Author(s):  
Shuyang Zhai ◽  
Wei Hu ◽  
Chen Fan ◽  
Wenqi Feng ◽  
Zhi-hong Liu
Keyword(s):  
Energy Transfer ◽  
Gold Nanoclusters ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Optical Probe ◽  
Luminescent Materials ◽  
Metal Nanoclusters ◽  
New Strategy ◽  
Photoluminescence Efficiency

Monolayer-protected metal nanoclusters (MPCs) are emerging as intriguing luminescent materials, but the construction of MPCs-based optical probe is still scarce because of both the limited photoluminescence efficiency of MPCs and...

scholarly journals Synthesis of Exosome-Based Fluorescent Gold Nanoclusters for Cellular Imaging Applications

2021 ◽  
Vol 22 (9) ◽  
pp. 4433
Author(s):  
Eun Sung Lee ◽  
Byung Seok Cha ◽  
Seokjoon Kim ◽  
Ki Soo Park
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Stokes Shift ◽  
Gold Nanoclusters ◽  
Human Colon ◽  
Cellular Imaging ◽  
Metal Nanoclusters ◽  
Human Colon Cancer ◽  
X Ray ◽  
High Concentrations

In recent years, fluorescent metal nanoclusters have been used to develop bioimaging and sensing technology. Notably, protein-templated fluorescent gold nanoclusters (AuNCs) are attracting interest due to their excellent fluorescence properties and biocompatibility. Herein, we used an exosome template to synthesize AuNCs in an eco-friendly manner that required neither harsh conditions nor toxic chemicals. Specifically, we used a neutral (pH 7) and alkaline (pH 11.5) pH to synthesize two different exosome-based AuNCs (exo-AuNCs) with independent blue and red emission. Using field-emission scanning electron microscopy, energy dispersive X-ray microanalysis, nanoparticle tracking analysis, and X-ray photoelectron spectroscopy, we demonstrated that AuNCs were successfully formed in the exosomes. Red-emitting exo-AuNCs were found to have a larger Stokes shift and a stronger fluorescence intensity than the blue-emitting exo-AuNCs. Both exo-AuNCs were compatible with MCF-7 (human breast cancer), HeLa (human cervical cancer), and HT29 (human colon cancer) cells, although blue-emitting exo-AuNCs were cytotoxic at high concentrations (≥5 mg/mL). Red-emitting exo-AuNCs successfully stained the nucleus and were compatible with membrane-staining dyes. This is the first study to use exosomes to synthesize fluorescent nanomaterials for cellular imaging applications. As exosomes are naturally produced via secretion from almost all types of cell, the proposed method could serve as a strategy for low-cost production of versatile nanomaterials.

scholarly journals An Antimicrobial Peptide-Loaded Chitosan/Polyethylene Oxide Nanofibrous Membrane Fabricated by Electrospinning Technology

2021 ◽  
Vol 8 ◽  
Author(s):  
Ling Yu ◽  
Shubin Dou ◽  
Jinghan Ma ◽  
Qiang Gong ◽  
Mogen Zhang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Polyethylene Oxide ◽  
Total Concentration ◽  
Average Diameter ◽  
Nanofiber Membrane ◽  
New Class ◽  
Intensity Changes ◽  
Good Biocompatibility ◽  
Nanofiber Membranes

Antimicrobial peptides (AMPs) are a new class of promising antibacterial agents. We prepared electrospinning chitosan (CS)-polyethylene oxide (PEO) nanofiber membranes containing different concentrations of an antibacterial peptide NP10. The average diameter of nanofibers increased with the total concentration of NP10. The FTIR shows that all the peaks of CS-PEO nanofiber membranes with different concentrations of NP10 were almost the same as those of pure CS-PEO nanofiber membranes, and only the peak intensity changes. Adding NP10 can improve the thermal stability of CS-PEO nanofiber membranes. In the in vitro release experiment, NP10 was released from the CS-PEO-0.5%NP10 nanofiber membrane in a burst first and then slowly and continuously. Simultaneously, the CS-PEO-NP10 nanofiber membrane had good antibacterial activity against Escherichia coli and Staphylococcus aureus and good biocompatibility. In animal wound healing experiments, CS-PEO-0.5%NP10 nanofiber membrane had advantages over gauze and CS-PEO nanofiber membrane in wound healing. These properties may provide a choice for the clinical application of AMPs and treatment of wound infections.

scholarly journals Synthesis and properties of lysosome-specific photoactivatable probes for live-cell imaging

2015 ◽  
Vol 6 (8) ◽  
pp. 4508-4512 ◽  
Author(s):  
Mai N. Tran ◽  
Robert-André F. Rarig ◽  
David M. Chenoweth
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Stokes Shift ◽  
Live Cell ◽  
Large Stokes Shift ◽  
New Class

We describe the synthesis and application of a new class of large Stokes shift lysosome-specific photoactivatable probes for live-cell imaging.

scholarly journals Excited-state locked amino analogues of the green fluorescent protein chromophore with a giant Stokes shift

RSC Advances ◽  
2019 ◽  
Vol 9 (66) ◽  
pp. 38730-38734 ◽  
Author(s):  
Snizhana O. Zaitseva ◽  
Dilara A. Farkhutdinova ◽  
Nadezhda S. Baleeva ◽  
Alexander Yu. Smirnov ◽  
Marina B. Zagudaylova ◽  
...  
Keyword(s):  
Excited State ◽  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Stokes Shift ◽  
Large Stokes Shift ◽  
New Class ◽  
Green Fluorescent

We design a new class of excited-state locked GFP chromophores which intrinsically exhibit a very large Stokes shift.

Fabrication and Characterization Studies of Semiconductor-Impregnated Porous Vycor Glass

1989 ◽  
Vol 164 ◽  
Author(s):  
C. A. Huber ◽  
T. E. Huber ◽  
A. P. Salzberg ◽  
J. A. Perez
Keyword(s):  
Electrical Transport ◽  
Quantum Confinement ◽  
Characteristic Size ◽  
Vycor Glass ◽  
New Class ◽  
Transport Studies ◽  
Porous Vycor Glass ◽  
Characterization Studies ◽  
Fabrication And Characterization ◽  
Interconnected Pores

AbstractPorous Vycor glass has been impregnated with semiconductors by pressure forcing the nonwetting semiconductor melt into the interconnected pores. Dense semiconductor mesh-like microstructures with a characteristic size of 50 Å can be fabricated by this technique. Measurements are reported which show the composites are suitable for both optical and transport studies, particularly those addressing quantum confinement of carriers and unusual electrical transport phenomena in this new class of materials.

scholarly journals Synthesis and Photoluminescence Study of Bi3+and Pb2+Activated Ca3(BO3)2

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
A. B. Gawande ◽  
R. P. Sonekar ◽  
S. K. Omanwar
Keyword(s):  
Stokes Shift ◽  
Solution Combustion Synthesis ◽  
Optimum Concentration ◽  
Prepared Phosphor ◽  
Luminescent Materials ◽  
Photoluminescence Properties ◽  
Solution Combustion ◽  
Sem Images ◽  
Synthesized Materials ◽  
Combustion Synthesis Technique

The photoluminescence properties of Pb2+and Bi3+doped Ca3(BO3)2prepared by solution combustion synthesis technique are discussed. The structure of the prepared phosphor is characterized and conformed by XRD and FTIR. SEM images of the prepared materials show irregular grains with agglomerate phenomena. Prepared phosphors achieved the band emissions, respectively, at 365 nm and 335 nm corresponding to the transitionP1→S013. Optimum concentration, critical transfer distance, and Stokes shift of the synthesized materials were measured. These phosphors may provide an efficient kind of luminescent materials for various applications in medical and industry.

ZnS nanocrystals co-activated by transition metals and rare-earth metals—a new class of luminescent materials

2001 ◽  
Vol 93 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Ping Yang ◽  
Mengkai Lü ◽  
Dong Xü ◽  
Duolong Yuan ◽  
Guangjun Zhou
Keyword(s):  
Rare Earth ◽  
Transition Metals ◽  
Rare Earth Metals ◽  
Luminescent Materials ◽  
New Class ◽  
Zns Nanocrystals

Thallium-Free Thermoelectric Materials with Extremely Low Thermal Conductivity

2007 ◽  
Vol 1044 ◽  
Author(s):  
Shinsuke Yamanaka ◽  
Ken Kurosaki ◽  
Anek Charoenphakdee ◽  
Hideaki Mastumoto ◽  
Hiroaki Muta
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
High Performance ◽  
Next Generation ◽  
Practical Application ◽  
Low Thermal Conductivity ◽  
New Class ◽  
Thallium Compounds ◽  
Thallium Tellurides

AbstractWith the goal of developing high-performance bulk thermoelectric materials, we have characterized ternary silver thallium tellurides. The ternary silver thallium tellurides exhibit extremely low thermal conductivity (<0.5 Wm−1K−1) and consequently their thermoelectric performance is excellent. Although the extremely low thermal conductivity materials, as typified by the ternary silver thallium tellurides, would be a new class of next-generation thermoelectric materials, thallium compounds are unsuitable for practical application because of their toxicity. Against such a background, we are currently exploring thallium-free thermoelectric materials with extremely low thermal conductivity. In this paper, we will briefly summarize the thermoelectric properties of ternary thallium tellurides obtained in our group. Further experiments aimed at improving the ZT of these materials will be presented. Finally, we will propose two candidates: Ag8GeTe6 and Ga2Te3 as thallium-free low thermal conductivity materials.

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