Reversible, photoresponsive, dynamic wide-range emission color from polymer-matrixed naphthalene diimide single-luminogen

Abstract Targeting of G-quadruplexes, non-canonical conformations that form in G-rich regions of nucleic acids, has been proposed as a novel therapeutic strategy toward several diseases, including cancer and infections. The unavailability of highly selective molecules targeting a G-quadruplex of choice has hampered relevant applications. Herein, we describe a novel approach, based on naphthalene diimide (NDI)-peptide nucleic acid (PNA) conjugates, taking advantage of the cooperative interaction of the NDI with the G-quadruplex structure and hybridization of the PNA with the flanking region upstream or downstream the targeted G-quadruplex. By biophysical and biomolecular assays, we show that the NDI-PNA conjugates are able to specifically recognize the G-quadruplex of choice within the HIV-1 LTR region, consisting of overlapping and therefore mutually exclusive G-quadruplexes. Additionally, the conjugates can induce and stabilize the least populated G-quadruplex at the expenses of the more stable ones. The general and straightforward design and synthesis, which readily apply to any G4 target of choice, together with both the red-fluorescent emission and the possibility to introduce cellular localization signals, make the novel conjugates available to selectively control G-quadruplex folding over a wide range of applications.

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Facile and rapid synthesis of emission color-tunable molybdenum oxide quantum dots as a versatile probe for fluorescence imaging and environmental monitoring

The Analyst ◽

10.1039/d0an01510e ◽

2020 ◽

Vol 145 (19) ◽

pp. 6270-6276

Author(s):

Haiyan Cao ◽

Mingjie Tang ◽

Xin Wang ◽

Wenbing Shi

Keyword(s):

Quantum Dots ◽

Environmental Monitoring ◽

Fluorescence Imaging ◽

Molybdenum Oxide ◽

Rapid Synthesis ◽

Emission Color ◽

Wide Range ◽

Color Tunable ◽

Signal Output

Colour-tunable N,P-MoOx QDs with dual-signal output have been used for achieving a multifunctional probe for the determination of a wide range of pH changes (2–9) and environmental sensing.

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Emission Color Tuning of Ge Nanoparticles in the Ranging from UV through Visible to near-IR

MRS Proceedings ◽

10.1557/opl.2013.1020 ◽

2013 ◽

Vol 1551 ◽

pp. 53-59 ◽

Cited By ~ 2

Author(s):

Naoto Shirahata

Keyword(s):

Spectral Line ◽

Structural Phase ◽

Spectral Lines ◽

Fine Tuning ◽

Fluorescence Labeling ◽

Quantum Yields ◽

Synthetic Process ◽

Near Ir ◽

Emission Color ◽

Wide Range

ABSTRACTThis paper presents that the fine tuning of efficient fluorescence emission in a very wide range of wavelength from near-UV through visible to near-IR by control over size, structural phase, and surface of germanium nanoparticles (Ge NPs). To achieve this, we prepared two parent samples composed of NPs with different emission photon energies, and separated the NPs by emission color through a combinatorial column techniques. In the NPs obtained by the separation, the spectral line widths of each emission became very narrow. Furthermore, the absolute fluorescence quantum yields for each emission were high enough for the industrial use of fluorescence labeling tags. Another scientific impact is the finding of new family of luminescent Ge, that is, the NPs emitting the lights in the violet and green-gap wavelength regions, respectively. It is commonly believed that a broad spectral line width frequently observed from Ge NP appears due to an indirect bandgap nature inherited even in nanostructures, but the present study provides obvious experimental evidences that a broad luminescence spectrum is expressed as ensemble of different spectral lines, and can be separated into the fractions emitting the lights in each wavelength region by the appropriate post-synthetic process.

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Metal Ions Doping for Boosting Luminescence of Lanthanide-Doped Nanocrystals

Frontiers in Chemistry ◽

10.3389/fchem.2020.610481 ◽

2020 ◽

Vol 8 ◽

Author(s):

Shihao Pei ◽

Xiaoqian Ge ◽

Lining Sun

Keyword(s):

Energy Transfer ◽

Metal Ion ◽

Upconversion Luminescence ◽

Relevant Literature ◽

Electric Dipole Transition ◽

Host Lattice ◽

High Signal ◽

Luminescence Efficiency ◽

Emission Color ◽

Wide Range

With the developing need for luminous materials with better performance, lanthanide-doped nanocrystals have been widely studied for their unique luminescence properties such as their narrow bandwidth emission, excellent chemical stability, and photostability, adjustable emission color, high signal-to-background ratio, deeper tissue penetration with less photo-damage, and low toxicity, etc., which triggered enthusiasm for research on the broad applications of lanthanide-doped nanocrystals in bioimaging, anti-counterfeiting, biosensing, and cancer diagnosis and treatment. Considerable progress has been made in the past few decades, but low upconversion luminescence efficiency has been a hindrance in achieving further progress. It is necessary to summarize the recently relevant literature and find solutions to improve the efficiency. The latest experimental and theoretical studies related to the deliberate design of rare earth luminescent nanocrystals have, however, shown the development of metal ion-doped approaches to enhance the luminescent intensity. Host lattice manipulation can enhance the luminescence through increasing the asymmetry, which improves the probability of electric dipole transition; and the energy transfer modulation offers a reduced cross-relaxation pathway to improve the efficiency of the energy transfer. Based on the mechanisms of host lattice manipulation and energy transfer modulation, a wide range of enhancements at all wavelengths or even within a particular wavelength have been accomplished with an enhancement of up to a hundred times. In this mini review, we present the strategy of metal ion-doped lanthanide nanocrystals to cope with the issue of enhancing luminescence, overview the advantages and tricky challenges in boosting the luminescence, and provide a potential trend of future study in this field.

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Wide range tuning of the size and emission color of CH3NH3PbBr3 quantum dots by surface ligands

AIP Advances ◽

10.1063/1.4994995 ◽

2017 ◽

Vol 7 (8) ◽

pp. 085217 ◽

Cited By ~ 8

Author(s):

Xin Fang ◽

Wenhao Zhai ◽

Kun Zhang ◽

Yilun Wang ◽

Li Yao ◽

...

Keyword(s):

Quantum Dots ◽

Surface Ligands ◽

Emission Color ◽

Wide Range

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Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070199 ◽

1978 ◽

Vol 36 (3) ◽

pp. 470-482 ◽

Cited By ~ 1

Author(s):

R.W. Horne

Keyword(s):

Electron Microscopy ◽

Image Processing ◽

Analytical Techniques ◽

Staining Technique ◽

High Resolution Electron Microscopy ◽

Optical Diffraction ◽

Full Potential ◽

Virus Particles ◽

Resolution Electron ◽

Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

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Microfabrication research at the National Submicron Facility

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074331 ◽

1983 ◽

Vol 41 ◽

pp. 86-89

Author(s):

E.D. Wolf

Keyword(s):

Integrated Circuits ◽

Particle Physics ◽

High Speed ◽

New Technology ◽

High Energy ◽

High Energy Particle ◽

New Science ◽

Wide Range ◽

Intermediate Domain ◽

Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

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Application of TEM to Deformation, Wear, and Fracture of Ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052377 ◽

1974 ◽

Vol 32 ◽

pp. 472-473

Author(s):

B. J. Hockey

Keyword(s):

Wear Resistance ◽

High Temperature ◽

Mechanical Behavior ◽

Brittle Materials ◽

High Temperature Strength ◽

Wide Range ◽

Corrosive Environments ◽

Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

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Observation of Atom Rows in Thorium Pyromellitate Using a Field Emission STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007802x ◽

1977 ◽

Vol 35 ◽

pp. 80-81

Author(s):

H. Todokoro ◽

S. Nomura ◽

T. Komoda

Keyword(s):

Field Emission ◽

Amorphous Carbon ◽

Carbon Film ◽

Dark Field Image ◽

Dark Field ◽

Amorphous Carbon Film ◽

Atomic Size ◽

Wide Range ◽

A Chain

It is interesting to observe polymers at atomic size resolution. Some works have been reported for thorium pyromellitate by using a STEM (1), or a CTEM (2,3). The results showed that this polymer forms a chain in which thorium atoms are arranged. However, the distance between adjacent thorium atoms varies over a wide range (0.4-1.3nm) according to the different authors.The present authors have also observed thorium pyromellitate specimens by means of a field emission STEM, described in reference 4. The specimen was prepared by placing a drop of thorium pyromellitate in 10-3 CH3OH solution onto an amorphous carbon film about 2nm thick. The dark field image is shown in Fig. 1A. Thorium atoms are clearly observed as regular atom rows having a spacing of 0.85nm. This lattice gradually deteriorated by successive observations. The image changed to granular structures, as shown in Fig. 1B, which was taken after four scanning frames.

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