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Chiral Sensor

Huan Zhang, Hui He, Xuemei Jiang, Zhining Xia, Weili Wei
Two dimensional (2D) transition metal dichalcogenides (TMDs) had attracted enormous interests owing to their extraordinary optical, physical and chemical properties. Herein, we prepared for the first time a series of chiral TMD QDs from MoS2 and WS2 bulk crystals by covalent modification with chiral ligands cysteine and penicillamine. The chiral TMD QDs were carefully investigated by spectroscopic and microscopic techniques. Their chiral optical activity was confirmed by distinct circular dichroism signals different to those of the chiral ligands...
August 16, 2018: ACS Applied Materials & Interfaces
Shi-Fan Xue, Xin-Yue Han, Zi-Han Chen, Qing Yan, Zi-Yang Lin, Min Zhang, Guoyue Shi
Screening functional DNA that can fruitfully interact with metal ions is one of long-standing hot topics in the fields biotechnology, medicine, and DNA-based sensors. In this contribution, we herein focus on the chemistry of europium (III) (Eu) coupled with single-stranded DNA (ssDNA), and innovatively unveil that cytosine and thymine-rich ssDNA oligomers (e.g. C16 and T16) can be effective antenna ligands to sensitize the luminescence of Eu. Luminescence lifetime spectroscopy, circular dichroism (CD) spectroscopy, and isothermal titration calorimetry (ITC) have been used to systematically characterize the interaction involved in Eu and ssDNA...
August 13, 2018: Analytical Chemistry
Yongping Liao, Hua Jiang, Nan Wei, Patrik Laiho, Qiang Zhang, Sabbir A Khan, Esko I Kauppinen
In floating catalyst chemical vapor deposition (FC-CVD), tuning chirality distribution and obtaining narrow chirality distribution of single-walled carbon nanotubes (SWCNTs) is challenging. Herein, by introducing various amount of CO2 in FC-CVD using CO as a carbon source, we have succeeded in directly synthesizing SWCNT films with tunable chirality distribution as well as tunable colors. In particular, with 0.25 and 0.37 volume percent of CO2 , the SWCNT films display green and brown colors, respectively. We ascribed various colors to suitable diameter and narrow chirality distribution of SWCNTs...
August 8, 2018: Journal of the American Chemical Society
Zeus A De Los Santos, Leo A Joyce, Edward C Sherer, Christopher J Welch, Christian Wolf
The determination of the enantiopurity and the concentration of chiral compounds by chiroptical sensing with molecular probes is increasingly attractive for high-throughput screening applications including streamlined asymmetric reaction development. In this study, we use stereodynamic aluminum biphenolate complexes for quantitative ee and concentration analysis of amino alcohols and α-hydroxy acids. An important feature of the tropos biphenolate ligand used is the presence of a phenylacetylene antenna for optimal chirality recognition and CD/UV responses at high wavelengths...
July 27, 2018: Journal of Organic Chemistry
Zilong Wu, Yaoran Liu, Eric H Hill, Yuebing Zheng
Chiral metamaterials have attracted strong interest due to their versatile capabilities in spin-dependent light manipulation. Benefiting from advancements in nanofabrication and mechanistic understanding of chiroptical effects, chiral metamaterials have shown potential in a variety of applications including circular polarizers, chiral sensors, and chiroptical detectors. Recently, chiral metamaterials made by moiré stacking, superimposing two or more periodic patterns with different lattice constants or relative spatial displacement, have shown promise for chiroptical applications...
July 13, 2018: Nanoscale
Jiapei Yang, Yin Yu, Datong Wu, Yongxin Tao, Linhong Deng, Yong Kong
Polypyrrole (PPy) was synthesized by a galvanostatic method using (1 S)-(+)-10-camphorsulfonic acid ((+)-CSA) as the dopant, and the produced PPy was further overoxidized in a solution of (+)-CSA. A chiral microenvironment was successfully formed in the overoxidized PPy (OPPy) as a result of the synergistic effects of overoxidation and (+)-CSA, resulting in a twisted helical architecture of the OPPy chains. The formation of optically active OPPy was confirmed from aspects of its morphology (SEM and AFM) and circular-dichroism (CD) spectra...
July 24, 2018: Analytical Chemistry
Yuxia Tang, Yingzhou Huang, Linhong Qv, Yurui Fang
Metal nanoparticle-film system has been proved that it has the ability of focusing light in the gap between particle and film, which is useful for surface-enhanced Raman scattering and plasmon catalysis. The rapid developed plasmonic chirality can also be realized in such system. Here, we investigated an electromagnetic energy focusing effect and chiral near-field enhancement in a coupled chiral particle chain on gold film. It shows large electric field enhancement in the gap between particle and film, as well as chiral near field...
July 5, 2018: Nanoscale Research Letters
Dan Liu, Yanyan Zhou, Yuan Zhang, Hongfeng Li, Peng Chen, Wenbin Sun, Ting Gao, Pengfei Yan
Chiral lanthanide helical architectures have received intense attentions in recent years because of their potential applications as chiral probes and sensors and as circularly polarized luminescence (CPL) materials. However, stereoselectivity control in the self-assembly of lanthanide helicate is challenging due to the poor stereochemical preference and variable coordination numbers of Ln(III) ions. Herein, we reported the employing chiral ancillary ligand R/S-BINAPO to induce achiral tripodal ligand to form a pair of homochiral lanthanide triple-helical podates [Eu(TTEA)((R/S)-BINAPO); R/S-1] {(R/S)-BINAPO = ( R/ S)-2,2'-bis(diphenylphosphoryl)-1,1'-binaphthyl; TTEA = tris[(4-(4,4,4-trifluoro-1,3-dioxobutyl)-benzamido)ethyl]amine}...
July 16, 2018: Inorganic Chemistry
Yuwei Sun, Yong Wang, Yifan Wu, Xuepeng Wang, Xianggao Li, Shirong Wang, Yin Xiao
This work reported the construction of a chiral sensor based on an organic field-effect transistor  to probe the subtle change of weak interactions in the chiral discrimination process, with the ability to achieve fast, sensitive, and quantitative real-time chiral analysis for various racemic pairs, where a β-cyclodextrin (β-CD) sensitized copper hexadecafluorophthalocyanine (F16 CuPc) semiconductive layer was employed as the sensing unit. Physical adsorptive assembly of β-CD on the semiconductive layer guarantees the impressive field-effect-amplified chiral sensitivity...
July 10, 2018: Analytical Chemistry
Datong Wu, Yin Yu, Jie Zhang, Lili Guo, Yong Kong
Here, a novel fluorescent chiral poly(ionic liquid) ( S)-PCIL-4 with nonconjugated backbone is designed and synthesized in the control of micelle through free-radical polymerization, whose fluorescence emission maximum is at λem,max = 430 nm. It is observed that polymers with spatially proximate units (phenyl group and pyridinium cation) have photoluminescence through spatial π-π and ion-π interaction. Then, ( S)-PCIL-4 can be served as a fluorescent turn off/on sensor for chiral recognition of phenylalaninol and tryptophan in the presence of Cu(II)...
July 11, 2018: ACS Applied Materials & Interfaces
Chiara Zanchi, Andrea Lucotti, Damiano Cancogni, Francesca Fontana, Sebastiano Trusso, Paolo M Ossi, Matteo Tommasini
Nanostructured gold thin films can be fabricated by controlled pulsed laser deposition to get efficient sensors, with uniform morphology and optimized plasmon resonance, to be employed as plasmonic substrates in surface enhanced Raman scattering spectroscopy. By attaching 5-aza[5]helicen-6-yl-6-hexanethiol to such gold nanostructures, used in a previous work for label-free drug sensing with biomedical purposes, we successfully prepared functionalized substrates with remarkable surface enhanced Raman scattering activity...
July 2018: Chirality
Anvar S Baimuratov, Tatiana P Pereziabova, Mikhail Yu Leonov, Weiren Zhu, Alexander V Baranov, Anatoly V Fedorov, Yurii K Gun'ko, Ivan D Rukhlenko
The search for the optimal geometry of optically active semiconductor nanostructures is making steady progress and has far-reaching benefits. Yet the helical springlike shape, which is very likely to provide a highly dissymmetric optical response, remains somewhat understudied theoretically. Here we comprehensively analyze the optical activity of semiconductor nanosprings using a fully quantum-mechanical model of their electronic subsystem and taking into account the anisotropy of their interaction with light...
June 4, 2018: ACS Nano
Zheng Cui, Lei Zhou, Bowen Qin, Baolei Zhou, Xiaoying Zhang, Wenliang Li, Jingping Zhang
The chiral Zn(ii) metal-organic framework [(CH3)2NH2]5[Zn1.5(Zn3O)(TATAT)2]·9DMF·17H2O (1) has been prepared from achiral precursors Zn(NO3)2·6H2O and 5,5',5''-(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)triisophthalate (H6TATAT) in a solvent mixture of DMF/MeOH/H2O/HCOOH without any chiral sources. In particular, the non-random handedness excess (1P ≫ 1M) was generated and was verified by single-crystal X-ray diffraction and solid-state circular dichroism spectroscopy. Furthermore, complex 1 displays high selectivity and sensitivity for detecting Fe3+ and is found to be an excellent chemical sensor for detecting nitro explosives especially 3-nitrophenol...
June 19, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Yu-Ting Tseng, Hsiang-Yu Chang, Scott G Harroun, Chien-Wei Wu, Shih-Chun Wei, Zhiqin Yuan, Hung-Lung Chou, Ching-Hsiang Chen, Chih-Ching Huang, Huan-Tsung Chang
Stereospecific recognition of chiral molecules is ubiquitous in chemical and biological systems, thus leading to strong demand for the development of enantiomeric drugs, enantioselective sensors, and asymmetric catalysts. In this study, we demonstrate the ratio of d-Cys and l-Cys playing an important role in determining the optical properties and the structures of self-assembled Cys-Au(I) supramolecules prepared through a simple reaction of tetrachloroaurate(III) with chiral cysteine (Cys). The irregularly shaped -[d-Cys-Au(I)] n - or - [l-Cys-Au(I)] n - supramolecules with a size larger than 500 nm possessing strong absorption in the near-UV region and chiroptical characteristics were only obtained from the reaction of Au(III) with d-Cys or l-Cys...
June 19, 2018: Analytical Chemistry
Yuki Imai, Yuka Nakano, Tsuyoshi Kawai, Junpei Yuasa
The potential use of circularly polarized luminescence for object identification in a sensor application is demonstrated. New luminescence probes using pyrene derivatives as sensor luminophores were developed. (R,R)-Im2 Py and (S,S)-Im2 Py contain two chiral imidazole moieties at 1,6-positions through ethynyl spacers (angle between spacers ca. 180°). The probe molecules spontaneously self-assemble into chiral stacks (P or M helicity) upon coordination to metal ions with tetrahedral coordination (Zn2+ ). The chiral probes display neither circular dichroism (CD) nor circularly polarized luminescence (CPL) without metal ions...
July 16, 2018: Angewandte Chemie
Pan Wang, Intak Jeon, Zhou Lin, Martin D Peeks, Suchol Savagatrup, Steven E Kooi, Troy Van Voorhis, Timothy M Swager
Materials with magneto-optic (MO) properties have enabled critical fiber-optic applications and highly sensitive magnetic field sensors. While traditional MO materials are inorganic in nature, new generations of MO materials based on organic semiconducting polymers could allow increased versatility for device architectures, manufacturing options, and flexible mechanics. However, the origin of MO activity in semiconducting polymers is far from understood. In this paper, we report high MO activity observed in a chiral helical poly-3-(alkylsulfone)thiophene (P3AST), which confirms a new design for the creation of a giant Faraday effect with Verdet constants up to (7...
May 23, 2018: Journal of the American Chemical Society
Haiyan Yuan, Yunmei Huang, Jidong Yang, Yuan Guo, Xiaoqing Zeng, Shang Zhou, Jiawei Cheng, Yuhui Zhang
In this study, a novel aptamer - based fluorescence bio-sensor (aptamer-AuNps) was developed for chiral recognition of arginine (Arg) enantiomers based on aptamer and gold nanoparticles (AuNps). Carboxyfluorescein (FAM) labeled aptamers (Apt) were absorbed on AuNps and their fluorescence intensity could be significantly quenched by AuNps based on fluorescence resonance energy transfer (FRET). Once d-Arg or l-Arg were added into the above solution, the aptamer specifically bind to Arg enantiomers and released from AuNps, so the fluorescence intensity of d-Arg system and l-Arg system were all enhanced...
July 5, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Zilong Wu, Xiaodong Chen, Mingsong Wang, Jianwen Dong, Yuebing Zheng
Ultrathin active chiral metamaterials with dynamically tunable and responsive optical chirality enable new optical sensors, modulators, and switches. Herein, we develop ultrathin active chiral metamaterials of highly tunable chiroptical responses by inducing tunable near-field coupling in the metamaterials and exploit the metamaterials as ultrasensitive sensors to detect trace amounts of solvent impurities. To demonstrate the active chiral metamaterials mediated by tunable near-field coupling, we design moiré chiral metamaterials (MCMs) as model metamaterials, which consist of two layers of identical Au nanohole arrays stacked upon one another in moiré patterns with a dielectric spacer layer between the Au layers...
May 22, 2018: ACS Nano
Erhan Zor
Paper-based sensors open new avenue to produce simple, rapid, inexpensive and single-use analytical devices for a wide application fields involving medical diagnosis, food analysis and environmental monitoring. In this study, a new optical sensing platform for enantioselective recognition of chiral analytes was introduced by using in-situ synthesized silver nanoparticles-embedded transparent nanopaper. To this aim, nanopaper was obtained by environment-friendly approach using bacterial cellulose made of nanofibers and silver nanoparticles were embedded within nanopaper by an in-situ generation method...
July 1, 2018: Talanta
Kai Miao, Yi Hu, Li Xu, Meiqiu Dong, Juntian Wu, Xinrui Miao, Wenli Deng
Owing to a wide range of applications within the areas such as chiral sensors, enantiomeric resolution, and asymmetric catalysis, understanding chiral adsorption phenomena at the interface is thereby of great importance. In particular, the role of multiple hydrogen bonds in inducing chiral diversiform morphologies has never been systematically investigated. Herein, by delicate control of the volume ratio of 1-octanoic acid and 1-octanol as the mixed solvent, a series of self-assembled nanostructures of 2-hydroxyl-7-pentadecyloxy-fluorenone (HPF) were sequentially fabricated, including the achiral densely-packed pattern, the chiral "6-2" pattern, the chiral alternate pattern, and the chiral double-rosette pattern...
April 25, 2018: Physical Chemistry Chemical Physics: PCCP
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