A quantum chemical approach to the design of chiral negative index materials

Baev, Alexander; Samoć, Marek; Prasad, Paras N.; Krykunov, Mykhaylo; Autschbach, Jochen

doi:10.1364/oe.15.005730

Cited by 51 publications

(52 citation statements)

References 26 publications

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“…Our observation is also unrelated to the previously reported phenomenon of CD spectra from a biomacromolecule being enhanced in the presence of a plasmonic particle 22,23 . This resonant enhancement arises because an electronic transition of the molecular system overlaps with the plasmonic resonance of the particle.…”

supporting

confidence: 55%

Ultrasensitive detection and characterization of biomolecules using superchiral fields

et al. 2010

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The spectroscopic analysis of large biomolecules is important in applications such as biomedical diagnostics and pathogen detection 1,2 , and spectroscopic techniques can detect such molecules at the nanogram level or lower. However, spectroscopic techniques have not been able to probe the structure of large biomolecules with similar levels of sensitivity. Here we show that superchiral electromagnetic fields 3 , generated by the optical excitation of plasmonic planar chiral metamaterials 4,5 , are highly sensitive probes of chiral supramolecular structure. The differences in the effective refractive indices of chiral samples exposed to left-and right-handed superchiral fields are found to be up to 10 6 times greater than that those observed in optical polarimetry measurements, thus allowing picogram quantities of adsorbed molecules to be characterised. The largest differences are observed for biomolecules that possess chiral planar 2 sheets, such as proteins with high β-sheet content, which suggest that this approach could form the basis for assaying technologies capable of detecting amyloid diseases and certain types of viruses.Since the building blocks of life are chiral molecular units such as amino acids and sugars, biomacromolecules formed from these units also exhibit chirality on molecular and supramolecular scales. Chirally sensitive (chiroptical) spectroscopic techniques, such as circular dichroism (CD), optical rotatory dispersion (ORD) and Raman optical activity (ROA), are therefore especially incisive probes of the threedimensional aspects of biomacromolecular structure and are widely used in biomolecular science 1,2 . Chiroptical methods typically measure small differences, or dissymmetries, in the interaction of left-and right-circularly polarised light, the chiral probe, with a chiral material 2 . However, the inherent weakness of these existing chiroptical phenomena usually restricts their application to samples of microgram level. Recently, Tang and Cohen 3 postulated that under certain circumstances superchiral electromagnetic fields could be produced that display greater chiral asymmetry than circularly polarised plane light waves. We have realised such superchiral electromagnetic fields are generated in the near fields of PCMs, and can greatly enhanced the sensitivity of a chiroptical measurement, enabling us to detect and characterise just a few picograms of a chiral material.PCMs were first fabricated, and shown to display large chiroptical effects such as optical rotation, by Schwanecke and co-workers 4 and Gonokami and co-workers 5 .The PCMs used in this study, Fig. 1 (a), are composed of left or right handed (LH / RH) Au gammadions, of length 400 nm and thickness 100 nm (plus a 5 nm Cr adhesion layer) deposited on a glass substrate and arranged in a square lattice with a periodicity of 800 nm. As a control we repeated all experiments using a metamaterial composed of achiral crosses with the same thickness and periodicity as the gammadions: these structures showed no dissymmetry in excita...

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confidence: 55%

Ultrasensitive detection and characterization of biomolecules using superchiral fields

et al. 2010

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“…The majority of work performed in this area is devoted to the conformational analysis of epimers, as well as computational modeling and materials design based on molecular chirality. [44][45][46][47] QC calculations in this work were performed using GAUSSIAN-09 Revision C.1. 48 The most popular DFT method (B3LYP 49,50 ) with the basis set 6-31G(d) 51 was used for potential energy surface (PES) scanning and was followed by geometry optimization of the stable conformers found during PES scanning.…”

Section: Theoretical Dft Conformational Analysis Of (Rs)-and (Ss)-dmentioning

confidence: 99%

Impact of chirality on the photoinduced charge transfer in linked systems containing naproxen enantiomers

Khramtsova

Sosnovsky

Ageeva

et al. 2016

Phys. Chem. Chem. Phys.

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The model reaction of photoinduced donor-acceptor interaction in linked systems (dyads) has been used to study the comparative reactivity of a well-known antiinflammatory drug, (S)-naproxen (NPX) and its (R)-isomer. (R)-or (S)-NPX in these dyads is linked to (S)-N-methylpyrrolidine (Pyr) using a linear or cyclic amino acid bridge (AA or CyAA), to give (R)-/(S)-NPX-AA-(S)-Pyr flexible and (R)-/(S)-NPX-CyAA-(S)-Pyr rigid dyads. The donor-acceptor interaction is reminiscent of the binding (partial charge transfer, CT) and electron transfer (ET) processes involved in the extensively studied inhibition of the cyclooxygenase enzymes (COXs) by the NPX enantiomers. Besides that, both optical isomers undergo oxidative metabolism by enzymes from the P450 family, which also includes ET. The scheme proposed for the excitation quenching of the (R)-and (S)-NPX excited state in these dyads is based on the joint analysis of the chemically induced dynamic nuclear polarization (CIDNP) and fluorescence data. The 1 H CIDNP effects in this system appear in the back electron transfer in the biradical-zwitterion (BZ), which is formed via dyad photoirradiation. The rate constants of individual steps in the proposed scheme and the fluorescence quantum yields of the local excited (LE) states and exciplexes show stereoselectivity. It depends on the bridge's length, structure and solvent polarity. The CIDNP effects (experimental and calculated) also demonstrate stereodifferentiation. The exciplex quantum yields and the rates of formation are larger for the dyads containing (R)-NPX, which let us suggest a higher contribution from the CT processes with the (R)-optical isomer.

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“…A quantum chemical approach to the design of chiral negativeindex materials has shown that this can be achieved by introducing sharp plasmonic resonances with metal NPs. [117] …”

Section: Opticsmentioning

confidence: 99%

Chiral Gold Nanoparticles

2009

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Monolayer-protected gold nanoparticles have many appealing physical and chemical properties such as quantum size effects, surface plasmon resonance, and catalytic activity. These hybrid organic-inorganic nanomaterials have promising potential applications as building blocks for nanotechnology, as catalysts, and as sensors. Recently, the chirality of these materials has attracted attention, and application to chiral technologies is an interesting perspective. This minireview deals with the preparation of chiral gold nanoparticles and their chiroptical properties. On the basis of the latter, together with predictions from quantum chemical calculations, we discuss different models that were put forward in the past to rationalize the observed optical activity in metal-based electronic transitions. We furthermore critically discuss these models in view of recent results on the structure determination of some gold clusters as well as ligand-exchange experiments examined by circular dichroism spectroscopy. It is also demonstrated that vibrational circular dichroism can be used to determine the structure of a chiral adsorbate and the way it interacts with the metal. Finally, possible applications of these new chiral materials are discussed.

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A quantum chemical approach to the design of chiral negative index materials

Cited by 51 publications

References 26 publications

Ultrasensitive detection and characterization of biomolecules using superchiral fields

Ultrasensitive detection and characterization of biomolecules using superchiral fields

Impact of chirality on the photoinduced charge transfer in linked systems containing naproxen enantiomers

Chiral Gold Nanoparticles

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