scholarly journals Hg2+ Detection with Rational Design of DNA-Templated Fluorescent Silver Nanoclusters

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1699
Author(s):  
Liam Yourston ◽  
Polikron Dhoqina ◽  
Nolan Marshall ◽  
Rujani Mahmud ◽  
Ethen Kuether ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rational Design ◽  
Visible Spectral Range ◽  
Silver Nanoclusters ◽  
Hairpin Loop ◽  
Fluorescent Properties ◽  
Dna Oligonucleotides ◽  
Loop Sequence ◽  
Detectable Range ◽  
Additional Stability

Atomically precise silver nanoclusters (AgNCs) are small nanostructures consisting of only a few atoms of silver. The combination of AgNCs with cytosine-rich single-stranded oligonucleotides results in DNA-templated silver nanoclusters (DNA-AgNCs). DNA-AgNCs are highly luminescent and can be engineered with reproducible and unique fluorescent properties. Furthermore, using nucleic acids as templates for the synthesis of AgNCs provides additional practical benefits by expanding optical activity beyond the visible spectral range and creating the possibility for color tunability. In this study, we explore DNA oligonucleotides designed to fold into hairpin-loop (HL) structures which modulate optical properties of AgNCs based on the size of the loop containing different number of cytosines (HL-CN). Depending on the size of the loop, AgNCs can be manufactured to have either single or multiple emissive states. Such hairpin-loop structures provide an additional stability for AgNCs and further control over the base composition of the loop, allowing for the rational design of AgNCs’ optical properties. We demonstrate the potential of AgNCs in detecting Hg2+ by utilizing the HL-C13 design and its variants HL-T2C11, HL-T4C9, and HL-T6C7. The replacement of cytosines with thymines in the loop was intended to serve as an additional sink for mercury ions extending the detectable range of Hg2+. While AgNC@HL-T0C13 exhibits an interpretable quenching curve, AgNC@HL-T6C7 provides the largest detectable range of Hg2+. The results presented herein suggest that it is possible to use a rational design of DNA-AgNCs based on the composition of loop sequence in HL structures for creating biosensors to detect heavy metals, particularly Hg2+.

scholarly journals DNA-Templated Fluorescent Silver Nanoclusters Inhibit Bacterial Growth While Being Non-Toxic to Mammalian Cells

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4045
Author(s):  
Lewis Rolband ◽  
Liam Yourston ◽  
Morgan Chandler ◽  
Damian Beasock ◽  
Leyla Danai ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Antibacterial Properties ◽  
Silver Nanoclusters ◽  
Metal Nanoclusters ◽  
Fluorescent Properties ◽  
Dna Oligonucleotides ◽  
Mammalian Cell Lines ◽  
History Of ◽  
The Stability

Silver has a long history of antibacterial effectiveness. The combination of atomically precise metal nanoclusters with the field of nucleic acid nanotechnology has given rise to DNA-templated silver nanoclusters (DNA-AgNCs) which can be engineered with reproducible and unique fluorescent properties and antibacterial activity. Furthermore, cytosine-rich single-stranded DNA oligonucleotides designed to fold into hairpin structures improve the stability of AgNCs and additionally modulate their antibacterial properties and the quality of observed fluorescent signals. In this work, we characterize the sequence-specific fluorescence and composition of four representative DNA-AgNCs, compare their corresponding antibacterial effectiveness at different pH, and assess cytotoxicity to several mammalian cell lines.

Theoretical Framework of 1,3-Thiazolium-5-Thiolates Mesoionic Compounds: Exploring the Nature of Photophysical Properties and Molecular Nonlinearity

2020 ◽  
Author(s):  
Zeyu Liu ◽  
Shugui Hua ◽  
Tian Lu ◽  
Ziqi Tian
Keyword(s):  
Optical Properties ◽  
Rational Design ◽  
Rayleigh Scattering ◽  
Function Analysis ◽  
Theoretical Calculations ◽  
Photophysical Properties ◽  
Optical Nonlinearity ◽  
Nonlinear Properties ◽  
Photoelectric Performance ◽  
Wave Function Analysis

Inspired by a previous experimental study on the first-order hyperpolarizabilities of 1,3-thiazolium-5-thiolates mesoionic compounds using Hyper-Rayleigh scattering technique, we theoretically investigated the UV-Vis absorption spectra and every order polarizabilities of these mesoionic molecules. Based on the fact that the photophysical and nonlinear properties observed in the experiment can be perfectly replicated, our theoretical calculations explored the essential characteristics of the optical properties of the mesoionic compounds with different electron-donating groups at the level of electronic structures through various wave function analysis methods. The influence of the electron-donating ability of the donor on the optical properties of the molecules and the contribution of the mesoionic ring moiety to their optical nonlinearity are clarified, which have not been reported by any research so far. This work will help people understand the nature of optical properties of mesoionic-based molecules and provide guidance for the rational design of molecules with excellent photoelectric performance in the future.

Rational design of HA-AuNPs@AIEDs nanoassembly for activatable fluorescence detection of HAase and imaging in tumor cells.

2021 ◽  
Author(s):  
Shenglan Wang ◽  
Chong-Hua Zhang ◽  
Peisheng Zhang ◽  
Shu Chen ◽  
Zhi-ling Song ◽  
...  
Keyword(s):  
Optical Properties ◽  
Tumor Cells ◽  
Fluorescence Detection ◽  
Rational Design ◽  
High Brightness ◽  
Aggregation Induced Emission ◽  
Fluorescence Bioimaging ◽  
In Virtue Of

Aggregation induced emission (AIE) dots have gained broad attention in fluorescence bioimaging and biosensor in virtue of their distinctive optical properties of splendid biocompatibility, high brightness and good photostability. However,...

scholarly journals Changes in Optical Properties upon Dye–Clay Interaction: Experimental Evaluation and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel
Keyword(s):  
Optical Properties ◽  
Hybrid Materials ◽  
High Performance ◽  
Fluorescent Properties ◽  
Chemical Mechanisms ◽  
Strong Electrostatic Interaction ◽  
Potential Applications ◽  
Photochemical Properties ◽  
Physical And Chemical ◽  
The Relationship

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.

scholarly journals Microfluidic Optical Shutter Flexibly x-y Actuated via Electrowetting-on-Dielectrics with <20 ms Response Time

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Henning Fouckhardt ◽  
Johannes Strassner ◽  
Carina Heisel ◽  
Dominic Palm ◽  
Christoph Doering
Keyword(s):  
Optical Properties ◽  
Response Time ◽  
Visible Spectral Range ◽  
Contact Structures ◽  
Light Path ◽  
Cell Type ◽  
Electrically Conductive ◽  
Droplet Movement ◽  
In Series ◽  
Optical Shutter

Tunable microoptics deals with devices of which the optical properties can be changed during operation without mechanically moving solid parts. Often a droplet is actuated instead, and thus tunable microoptics is closely related to microfluidics. One such device/module/cell type is an optical shutter, which is moved in or out of the path of the light. In our case the transmitting part comprises a moving transparent and electrically conductive water droplet, embedded in a nonconductive blackened oil, that is, an opaque emulsion with attenuation of 30 dB at 570 nm wavelength over the 250 μm long light path inside the fluid (15 dB averaged over the visible spectral range). The insertion loss of the cell is 1.5 dB in the “open shutter” state. The actuation is achieved via electrowetting-on-dielectrics (EWOD) with rectangular AC voltage pulses of 2·90 V peak-to-peak at 1 kHz. To flexibly allow for horizontal, vertical, and diagonal droplet movement in the upright x-y plane, the contact structures are prepared such that four possible stationary droplet positions exist. The cell is configured as two capacitors in series (along the z axis), such that EWOD forces act symmetrically in the front and back of the 60 nl droplet with a response time of <20 ms.

Development of a Novel and Bi-Functional Quantum Dots as FRET Energy Donor

2010 ◽  
Vol 152-153 ◽  
pp. 1418-1421
Author(s):  
Yue Qian Yang ◽  
Shi Chao Xu ◽  
Heng Miao ◽  
Ji Mei Zhang ◽  
Zhao Dai ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Resonance Energy ◽  
Emission Peak ◽  
Layer By Layer ◽  
Peak Width ◽  
Fluorescent Properties ◽  
Energy Donor ◽  
Yellow Solution ◽  
High Fluorescence

A novel CdTe/Ni QDs which combined both magnetism and fluorescence was successfully synthesized and its optical properties were investigated. Ni magnetic nanoparticles (MNPs) were synthesized and used as magnetic core, CdTe quantum dots (QDs) were applied as fluorescent shell material, the qualified magnetic CdTe/Ni quantum dots (mQDs) were achieved via layer-by-layer process using 1,6-hexylenediamime as linker, surface charge types of MNPs and mQDs were confirmed with a delsa nano beckman coulter. Morphology of the prepared Ni MNPs and CdTe/Ni mQDs was characterized by transmission electron microscopy (TEM), and optical properties were investigated with fluorescence spectrum (FS). Qualified CdTe/Ni mQDs with high fluorescence and narrow maximum emission peak width were obtained under the optimum conditions. Surface zeta-potential of CdTe QDs and Ni MNPs were estimated to be -36.2 and 27.97mV, respectively. TEM data indicated that ca 20nm of Ni MNPs and ca 25nm of CdTe/Ni mQDs were prepared, respectively; the size-increasing indicated the formation of CdTe shell on the Ni MNPs core. Narrow half peak width of emission peak was detected and calculated to be about 50nm via FS. High fluorescence intensity of CdTe/Ni mQDs was determined and brilliant yellow solution was observed when excited under UV360nm. The synthesized CdTe/Ni mQDs showed excellent magnetic property, and can be magnetically concentrated with a common magnet. The obtained data indicated that the prepared bi-functional CdTe/Ni mQDs possess excellent magnetic and fluorescent properties, and it can be used as a energy donor in DNA sensing based on fluorescence resonance energy transfer (FRET).

Rational Design of Monocrystalline (InP)yGe5–2y/Ge/Si(100) Semiconductors: Synthesis and Optical Properties

2013 ◽  
Vol 135 (33) ◽  
pp. 12388-12399 ◽  
Author(s):  
Patrick E. Sims ◽  
Andrew V.G. Chizmeshya ◽  
Liying Jiang ◽  
Richard T. Beeler ◽  
Christian D. Poweleit ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rational Design

scholarly journals Effects of External Field Wavelength and Solvation on the Photophysical Property and Optical Nonlinearity of 1,3-Thiazolium-5-Thiolates Mesoionic Compound

2021 ◽  
Author(s):  
Shugui Hua ◽  
Zeyu Liu ◽  
Tian Lu
Keyword(s):  
Optical Properties ◽  
External Field ◽  
Rational Design ◽  
Function Analysis ◽  
Optical Nonlinearity ◽  
Photophysical Property ◽  
Polarizability Tensor ◽  
Mesoionic Compound ◽  
Density Analysis ◽  
Wave Function Analysis

<p>The photophysical property and optical nonlinearity of an electronic push-pull mesoionic compond, 2-(4-trifluoromethophenyl)-3-methyl-4-(4-methoxyphenyl)-1,3-thiazole-5-thiolate were theoretically investigated with a reliable computing strategy. The essence of the optical properties were then explored through a variety of wave function analysis methods, such as the natural transition orbital analysis, hole-electron analysis, (hyper)polarizability density analysis, decomposition of the (hyper)polarizability contribution by numerical integration, and (hyper)polarizability tensor analysis, at the level of electronic structures. The influence of the electric field and solvation on the electron absorption spectra and (hyper)polarizabilities of the molecule are highlighted and clarified. This work will help people to understand the influence of external field wavelength and solvent on the optical properties of mesoionic-based molecules, and provide a theoretical reference for the rational design of chromophores with adjustable properties in the future.<br></p><br>

scholarly journals First Step Towards Larger DNA-Based Assemblies of Fluorescent Silver Nanoclusters: Template Design and Detailed Characterization of Optical Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 613 ◽  
Author(s):  
Liam E. Yourston ◽  
Alexander Y. Lushnikov ◽  
Oleg A. Shevchenko ◽  
Kirill A. Afonin ◽  
Alexey V. Krasnoslobodtsev
Keyword(s):  
Optical Properties ◽  
Dna Sequences ◽  
Silver Nanoclusters ◽  
Conformational Heterogeneity ◽  
Individual Element ◽  
Double Stranded Dna ◽  
Close Proximity ◽  
Template Design ◽  
Fluorescent Nanomaterials

Besides being a passive carrier of genetic information, DNA can also serve as an architecture template for the synthesis of novel fluorescent nanomaterials that are arranged in a highly organized network of functional entities such as fluorescent silver nanoclusters (AgNCs). Only a few atoms in size, the properties of AgNCs can be tuned using a variety of templating DNA sequences, overhangs, and neighboring duplex regions. In this study, we explore the properties of AgNCs manufactured on a short DNA sequence—an individual element designed for a construction of a larger DNA-based functional assembly. The effects of close proximity of the double-stranded DNA, the directionality of templating single-stranded sequence, and conformational heterogeneity of the template are presented. We observe differences between designs containing the same AgNC templating sequence—twelve consecutive cytosines, (dC)12. AgNCs synthesized on a single “basic” templating element, (dC)12, emit in “red”. The addition of double-stranded DNA core, required for the larger assemblies, changes optical properties of the silver nanoclusters by adding a new population of clusters emitting in “green”. A new population of “blue” emitting clusters forms only when ssDNA templating sequence is placed on the 5′ end of the double-stranded core. We also compare properties of silver nanoclusters, which were incorporated into a dimeric structure—a first step towards a larger assembly.

Agar phantoms of biological tissue for fluorescence monitoring of photodynamic therapy

2022 ◽  
Vol 52 (1) ◽  
pp. 63-68
Author(s):  
A V Khilov ◽  
V A Shishkova ◽  
E A Sergeeva ◽  
D A Kurakina ◽  
M Yu Kirillin
Keyword(s):  
Optical Properties ◽  
Photodynamic Therapy ◽  
Intravenous Injection ◽  
Biological Tissue ◽  
Biological Tissues ◽  
Fluorescent Properties ◽  
Fluorescent Marker ◽  
Scattering Coefficients ◽  
Scattering Spectra ◽  
Good Agreement

Abstract An approach to fabricating agar phantoms mimicking spectral optical properties of biological tissues with fluorescent inclusions is proposed, which allows one to imitate the problem of optical visualisation of superficial biological tissues after the administration of a chlorin-based photosensitiser. The different arrangement of a fluorescent layer within a phantom makes it possible to simulate biological tissue in the cases of both topical application and intravenous injection of a photosensitiser. It is shown that absorption and scattering spectra of phantoms are in good agreement with the spectra of real biological tissues in the wavelength range of 500-800 nm. Changes in spectra of absorption and scattering coefficients of phantoms, as well as in their fluorescent properties induced by the addition of a fluorescent marker (chlorinbased photosensitiser) are demonstrated.

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