Article
Chemistry, Multidisciplinary
Pengtao Xu, Jin Suntivich
Summary: In situ stimulated Raman spectroscopy (SRS) is introduced as a method to monitor the evolution of electrochemical reactions with millisecond resolutions and enhanced sensitivity. The SRS methodology can identify generated chemicals during electrochemical reactions and observe the change in their concentration over time.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Physical
Max Lukas, Ellen H. G. Backus, Mischa Bonn, Maksim Grechko
Summary: SFG vibrational spectroscopy is a powerful technique to study interfaces. However, implementing this technique is challenging. In this study, a collinear PR-SFG setup using a displaced Sagnac interferometer is developed, which allows independent control of time delay and intensity and provides long-time phase stabilization for the measured signal.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Wiebke Haselbach, Jeremy M. Kaminski, Laura N. Kloeters, Thomas J. J. Mueller, Oliver Weingart, Christel M. Marian, Peter Gilch, Barbara E. Nogueira de Faria
Summary: The emitters for TADF-based OLEDs need to have small S-1-T-1 energy gaps and fast ISC transitions. Vibronic mixing with higher excited states S-n and T-n can mediate these transitions. By using time-resolved NIR spectroscopy, it is demonstrated that the energetically located higher states can be found in a prototypical TADF emitter consisting of a triarylamine and a dicyanobenzene moiety (TAA-DCN).
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Minhaeng Cho
Summary: Time-resolved IR pump-probe and two-dimensional IR spectroscopy are valuable techniques for studying ultrafast chemical and biological processes in solutions. However, distinguishing signals caused by local heating from genuine nonlinear IR signals poses a challenge in data interpretation.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Ian Gabalski, Felix Allum, Issaka Seidu, Mathew Britton, Gunter Brenner, Hubertus Bromberger, Mark Brouard, Philip H. Bucksbaum, Michael Burt, James P. Cryan, Taran Driver, Nagitha Ekanayake, Benjamin Erk, Diksha Garg, Eva Gougoula, David Heathcote, Paul Hockett, David M. P. Holland, Andrew J. Howard, Sonu Kumar, Jason W. L. Lee, Siqi Li, Joseph McManus, Jochen Mikosch, Dennis Milesevic, Russell S. Minns, Simon Neville, Christina C. Atia-Tul-Noor, Christina Papadopoulou, Christopher O. Passow, Weronika Razmus, Anja Roeder, Arnaud Rouzee, Alcides Simao, James Unwin, Claire Vallance, Tiffany Walmsley, Jun Wang, Daniel Rolles, Albert S. Stolow, Michael Schuurman, Ruaridh Forbes
Summary: Recent developments in X-ray free-electron lasers have enabled a novel site-selective probe of coupled nuclear and electronic dynamics in photoexcited molecules, known as time-resolved X-ray photoelectron spectroscopy (TRXPS). In this study, we investigate the ultraviolet photodissociation of CS2 and demonstrate that the binding energy of sulfur 2p is sensitive to changes in nuclear structure, leading to dissociation into CS and S photoproducts. The main X-ray spectroscopic features are assigned to the CS and S products using ab initio multiple-spawning simulations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Kai C. Gronborg, Sydney M. Giles, Sean Garrett-Roe
Summary: Angular momentum transfer and wavepacket dynamics of CO2(g) were measured on the picosecond time scale using polarization-resolved two-dimensional infrared (2D-IR) spectroscopy. Multiple rotational levels were observed simultaneously at room temperature, and the structure and spectral diffusion of the rotationally resolved 2D-IR spectrum were explained using nonlinear response function theory.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Multidisciplinary
Andres Montoya-Castillo, Michael S. Chen, Sumana L. Raj, Kenneth A. Jung, Kasper S. Kjaer, Tobias Morawietz, Kelly J. Gaffney, Tim B. van Driel, Thomas E. Markland
Summary: Time-resolved scattering experiments can image materials at the molecular scale with femtosecond time resolution. However, there are limitations in disordered media. In this study, a theoretical framework is introduced to predict and interpret experiments combining optically induced anisotropy and time-resolved scattering, and its accuracy is verified through chloroform experiments and simulations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Seongchul Park, Juhyang Shin, Manho Lim
Summary: The photodissociation dynamics of CF2BrCF2I in CCl4 solution at 280 ± 2 K were studied using time-resolved infrared spectroscopy. The dissociation of I or Br atoms occurred within 300 fs after excitation, forming CF2BrCF2 or CF2ICF2 radicals, respectively. CF2ICF2 further dissociated to CF2CF2 with a time constant of 56 ± 5 ns. g-CF2BrCF2 isomerized to a-CF2BrCF2 with a time constant of 47 ± 5 ps. a-CF2BrCF2 underwent bimolecular reactions with itself or Br in CCl4 solution at a diffusion-limited rate. The secondary dissociation of Br from a-CF2BrCF2 was slower than the bimolecular reactions. Approximately half of the excited CF2BrCF2I produced CF2BrCF2Br, while the other half produced CF2CF2. The excess energies in the nascent radicals thermalized faster than the secondary dissociation of I from CF2ICF2 and the observed bimolecular reactions, indicating that the secondary reactions occurred under thermal conditions. This study highlights the application of structure-sensitive time-resolved infrared spectroscopy in studying real-time reaction dynamics in solution.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Optics
Alberto Ghezzi, Armin J. M. Lenz, Fernando Soldevila, Enrique Tajahuerce, Vito Vurro, Andrea Bassi, Gianluca Valentini, Andrea Farina, Cosimo D'Andrea
Summary: In this work, we propose a time-resolved multispectral fluorescence microscopy system based on the Single-Pixel Camera (SPC) scheme, which achieves high resolution and short measurement time using Compressive Sensing (CS) technology. Data Fusion (DF) with a high-resolution camera is used to address the low spatial resolution issue typical of SPC. By integrating hardware and algorithms, this system reduces the number of measurements while preserving the information content, allowing for a zoom feature without moving the optical system. The system is characterized in terms of spatial, spectral, and temporal properties, and is validated on a cellular sample.
Article
Physics, Applied
S. Chaurasia, Ashutosh Mohan, Ajay K. Mishra, C. D. Sijoy, V. Mishra
Summary: This study investigates the molecular-level behavior of nitromethane (NM) under static and dynamic compression and reveals multiple phase transitions and shock velocities at different pressures through experiments and simulations.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Emily M. Warne, Adam D. Smith, Daniel A. Horke, Emma Springate, Alfred J. H. Jones, Cephise Cacho, Richard T. Chapman, Russell S. Minns
Summary: The photoelectron spectroscopy experiment investigates the products formed after the photodissociation of UV-excited CS2 using femtosecond XUV photons. The spectral analysis reveals separate photoelectron bands corresponding to different dissociation channels, with no delay in the appearance of the S(D-1) product. Analysis of the photoelectron yield provides insights into the branching ratio and rate constants associated with dissociation and intersystem crossing.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Lea Ress, Pavel Maly, Jann B. Landgraf, Dominik Lindorfer, Michael Hofer, Joshua Selby, Christoph Lambert, Thomas Renger, Tobias Brixner
Summary: This article presents the experimental and theoretical foundations for femtosecond time-resolved circular dichroism (TRCD) spectroscopy of excitonic systems. A new experimental setup, with a polarization grating as the key element, is introduced to generate circularly polarized pulses for TRCD experiments. By applying a specific chopping scheme, left and right circular polarizations can be switched, and transient absorption (TA) and TRCD spectra can be detected simultaneously. Experiments on a squaraine polymer are performed to investigate excitonic dynamics, and a general theory for TRCD experiments of excitonically coupled systems is developed and applied to describe the experimental data.
Article
Chemistry, Physical
Caleb J. C. Jordan, Jan R. R. Verlet
Summary: The study demonstrates the successful application of optical Kerr gating to overcome fluorescence interference in studying the excited state dynamics of molecules at interfaces using second-order non-linear spectroscopic methods. This new approach has been shown to be effective in discriminating against fluorescence signals in various systems.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
Yuushi Shimoda, Kiyoshi Miyata, Masataka Funaki, Takumi Ehara, Tatsuki Morimoto, Shunsuke Nozawa, Shin-ichi Adachi, Osamu Ishitani, Ken Onda
Summary: Through studying the photophysical properties of rhenium(I) diimine complexes, we found that the number of phenyl groups in the phosphine ligand can significantly affect the structure and fluorescence properties during the photoexcitation process.
INORGANIC CHEMISTRY
(2021)
Article
Biochemical Research Methods
Hanlin Zhu, Chenran Xu, Vladislav V. Yakovlev, Delong Zhang
Summary: Researchers used time-resolved coherent anti-Stokes Raman scattering (T-CARS) spectroscopy to detect adulteration in cooking oil and understand the mechanisms of lipid oxidation. By overcoming the limitations of conventional Raman spectroscopy, they found that intra-molecular interactions in triglycerides significantly influence vibrational dephasing time. They observed that although initial dephasing times varied, they converged to a similar value after heating cycles. Notably, longer vibrational dephasing of the CH2 symmetric stretching mode was found to correlate with a higher lipid oxidation rate.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2023)
Review
Biochemistry & Molecular Biology
Shiqin Miao, Yufeng Liang, Sarah Rundell, Debmalya Bhunia, Shekar Devari, Oliver Munyaradzi, Dennis Bong
Summary: The concept of using synthetic heterocycles in place of natural bases to interact with DNA and RNA has been studied for almost 60 years, with potential to expand genetic code and access new molecular functions. While much research focuses on code expansion, there is also increasing effort in docking synthetic heterocycles to noncoding nucleic acid interfaces to elucidate major nucleic acid processes. Both coding and noncoding interface research share fundamental principles in molecular recognition.
Article
Chemistry, Multidisciplinary
Alisina Bazrafshan, Maria-Eleni Kyriazi, Brandon Alexander Holt, Wenxiao Deng, Selma Piranej, Hanquan Su, Yuesong Hu, Afaf H. El-Sagheer, Tom Brown, Gabriel A. Kwong, Antonios G. Kanaras, Khalid Salaita
Summary: Research has shown that optimizing DNA motor performance can be achieved by adjusting structural parameters and buffer conditions. Increasing DNA leg density can improve speed and processivity, while DNA leg span can increase processivity and directionality. Label-free imaging has also revealed the unique motion patterns of the motors.
Article
Chemistry, Multidisciplinary
Yuesong Hu, Victor Pui-Yan Ma, Rong Ma, Wenchun Chen, Yuxin Duan, Roxanne Glazier, Brian G. Petrich, Renhao Li, Khalid Salaita
Summary: This study developed a DNA-based microparticle tension sensor for investigating mechanotransduction at curved interfaces with high throughput. The method successfully mapped and measured T-cell receptor forces and platelet integrin forces, demonstrating its potential in screening drugs that modulate cellular mechanics.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Virology
Graziely F. Cespedes, Thatyane M. Nobre, Osvaldo N. Oliveira, Dennis Bong, Eduardo M. Cilli
Summary: The study evaluated the impact of surrounding regions of fusion peptide on the interaction with the membrane and fusion activity in Dengue 2 subtype, finding the C-terminal region to be more efficient in promoting fusion and interacting with the membrane. A proposed 2-step mechanism for the interaction of dengue virus fusion peptide with the host membrane highlights the electrostatic docking of the N-terminal sequence and the hydrophobic interaction of the C-terminal region.
Article
Chemistry, Physical
Yuyuan Zhang, Chen He, Kimberly de la Harpe, Peter M. Goodwin, Jeffrey T. Petty, Bern Kohler
Summary: The specific nucleobase subunits within a DNA strand modulate cluster-ligand interactions and brightness, with guanosine and inosine affecting the fluorescence brightness and decay rate differently. Nonradiative decay is 7x higher with guanosine than inosine, indicating a potential correlation between nonradiative decay and selective coordination with specific nucleobase subunits.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Jennifer M. Empey, Christopher Grieco, Natasha W. Pettinger, Bern Kohler
Summary: The study reveals that electrons are injected into trap or defect states with Ce 5d character in CeO2 nanoparticles following photoexcitation of dye molecules. The decay of electrons in the oxidized dye is slightly slower than the mid-IR signals, indicating competition between electron relaxation within CeO2 and back-electron transfer to the dye. These results provide insights into elementary events crucial for understanding photocatalysis with CeO2 nanoparticles.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Biochemistry & Molecular Biology
Sarah Rundell, Oliver Munyaradzi, Dennis Bong
Summary: The study found that tuning the thymine-uracil substitutions and backbone structure can significantly improve the binding ability of bifacial peptide nucleic acids (bPNAs) to DNA and RNA, with a higher selectivity towards DNA. By improving backbone conformation and enhancing base stacking, the targeting ability of bPNAs to DNA and RNA substrates can be enhanced.
Article
Biochemistry & Molecular Biology
Oliver Munyaradzi, Sarah Rundell, Dennis Bong
Summary: This study investigates the impact of amino acid composition and backbone modification on DNA binding of bifacial peptide nucleic acid (bPNA). The results demonstrate the tunability of bPNA-DNA hybrid stability through bPNA backbone structural propensities and amino acid composition.
Article
Chemistry, Multidisciplinary
Yufeng Liang, Shiqin Miao, Jie Mao, Shekaraiah Devari, Maricarmen Gonzalez, Dennis Bong
Summary: The study explores programmable hybridization strategies at the macromolecular level through displaying binders to individual noncanonical nucleic acid motifs. Binding between probes and NCP sites is context-dependent and reflects molecular recognition and stability. More diverse binding profiles were observed in RNA substrates, especially in tandem NCP sites.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Shekaraiah Devari, Debmalya Bhunia, Dennis Bong
Summary: In this study, bifacial peptide nucleic acids (bPNAs) with novel diketopiperazine (DKP) backbones displaying unnatural melamine (M) bases and native bases were synthesized. The structure-function scope of DKP bPNAs was examined, and a set of bPNAs displaying different base-tripling motifs were prepared. Thermal denaturation studies revealed that the optimal side-chain linkage was four carbons, corresponding to the lysine derivative. With these building blocks, DKP bPNAs displaying a combination of native and synthetic bases were prepared. Preliminary melting studies indicate binding signatures of cytidine- and melamine-displaying bPNAs to T-rich DNAs of noncanonical structure. This convenient and potentially scalable method allows for the rapid generation of low molecular weight DNA-binding scaffolds with established cell permeability, enabling further studies on noncanonical nucleic acid hybridization.
Article
Medicine, Research & Experimental
Xijun Piao, Vibha Yadav, Eddie Wang, Wayne Chang, Lanna Tau, Benjamin E. Lindenmuth, Sharon X. Wang
Summary: This study proposes a simple, scalable, and controllable method to reduce the formation of dsRNA byproducts during in vitro transcription. The improved method produces mRNA with significantly less dsRNA, lower immuno-stimulation, and more efficient protein expression, potentially simplifying the mRNA manufacturing process.
MOLECULAR THERAPY-NUCLEIC ACIDS
(2022)
Article
Chemistry, Physical
Alex T. T. Hanes, Christopher Grieco, Remy F. F. Lalisse, Christopher M. M. Hadad, Bern Kohler
Summary: Two-dimensional infrared (2D IR) spectroscopy, infrared pump-infrared probe spectroscopy, and density functional theory calculations were used to investigate vibrational relaxation in methylated xanthine derivatives. The results showed biexponential decay of carbonyl stretch modes and a quantum beat in anisotropy signals. Coherent energy transfer and intramolecular vibrational redistribution were observed. The decay of ring modes was explained by intermolecular energy transfer to solvent modes. The coupling between carbonyl stretching modes and ring modes was found to be weak.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Xueqing Wang, Lilia Kinziabulatova, Marco Bortoli, Anju Manickoth, Marisa A. Barilla, Haiyan Huang, Lluis Blancafort, Bern Kohler, Jean-Philip Lumb
Summary: Melanins are biopolymers produced from phenols and catechols that provide various functions such as photoprotection, pigmentation, and redox activity. The chemical structures of melanins remain unknown, hindering the design of synthetic materials with specific properties. However, the stabilization of indole-5,6-quinone (IQ) derivatives has allowed the exploration of eumelanin's unique electronic and optical properties, which can contribute to the development of melanin-inspired materials.
Article
Multidisciplinary Sciences
Yufeng Liang, Sydney Willey, Yu-Chieh Chung, Yi-Meng Lo, Shiqin Miao, Sarah Rundell, Li-Chun Tu, Dennis Bong
Summary: FLURIL tagging method utilizes fluorogenic bPNA probes to label nucleic acids in fixed and live cells, while maintaining a light molecular footprint and compatibility with existing methods.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Zhiling Zhao, Eunkyoung Kim, Chen-Yu Chen, John R. Rzasa, Qian Zhang, Jinyang Li, Yang Tao, William E. Bentley, Jean-Philip Lumb, Bern Kohler, Gregory F. Payne
Summary: Catechol-based materials in redox-based bioelectronics possess diverse properties and can transduce near infrared (NIR) radiation into heat. The study shows that catechol-chitosan films can reversibly respond to both NIR and redox inputs, suggesting the independent flow of energy through catechol-based materials via redox and electromagnetic modalities. These findings highlight the potential of catecholic materials for bio-device communication, offering both short-range redox communication and long-range electromagnetic communication.
MATERIALS CHEMISTRY FRONTIERS
(2022)
