Article
Biotechnology & Applied Microbiology
Kasumi Nakagawa, Michiki Takeuchi, Mayu Kikuchi, Manami Tada, Takaiku Sakamoto, Kenji Kano, Jun Ogawa, Eiji Sakuradani
Summary: This study successfully applied cyclic voltammetry to in-vivo monitoring of leuco-indigo in indigo-fermenting suspensions, revealing no need for deoxygenation under quiescent conditions. The anodic peak current was used as a measure of leuco-indigo concentration. The method, which does not require electrode surface pretreatment, can reflect the dyeing activity of suspensions and clarify aspects such as the number of days required for dye fermentation and the importance of specific nutrient additions.
JOURNAL OF BIOSCIENCE AND BIOENGINEERING
(2021)
Article
Biotechnology & Applied Microbiology
Mayu Kikuchi, Keisei Sowa, Michiki Takeuchi, Kasumi Nakagawa, Momoka Matsunaga, Akinori Ando, Kenji Kano, Jun Ogawa, Eiji Sakuradani
Summary: This study demonstrated the use of normal pulse voltammetry for the detection and quantification of leuco-indigo in Aizome. The steady-state concentrations of leuco-indigo showed sigmoidal profiles in the depth direction, influenced by competitive reactions of microbial reduction and autoxidation. Understanding these factors is crucial for the proper management of indigo-dye-fermenting suspensions.
JOURNAL OF BIOSCIENCE AND BIOENGINEERING
(2022)
Article
Chemistry, Physical
Yu Kihara, Shuntaro Tani, Yamato Higashi, Takahiro Teramoto, Yutaka Nagasawa
Summary: Femtosecond time-resolved transient absorption spectroscopy was used to investigate the excited state dynamics of red-light-absorbing indigo derivatives. The study found that both trans -> cis and trans <- cis photoisomerization have short excited state lifetimes, and are influenced by intramolecular charge transfer.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Materials Science, Textiles
Hong Dinh Duong, Jong Il Rhee
Summary: In this study, the use of enzymes, such as glucose oxidase (GOD) and laccase (LAC), improved the reduction of indigo to leuco-indigo by glucose. These enzymes acted as electron carriers from reduced glucose or directly transferred electrons to indigo molecules, increasing the turnover rate of electron flow between glucose and indigo. As a result, leuco-indigo production was improved by 2-5 times compared to the rate without enzymes. Enzymatically reduced indigo was then used for dyeing ramie fabric.
FIBERS AND POLYMERS
(2023)
Article
Chemistry, Physical
Milena Mlakic, Leo Mandic, Nikola Basaric, Branka Mihaljevic, Fabijan Pavosevic, Irena Skoric
Summary: The study investigated the photochemical reactivity in Z-E isomerization for two heterostilbene derivatives containing 1,2,3-triazole unit. Different quantum yields and reaction mechanisms were found for cis- and trans-isomers, providing insights into the fundamental Z-E isomerization.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Chung-Yang (Dennis) Huang, Stefan Hecht
Summary: This review explores the significance of indigo as a historical dye and its recent potential as a functional motif due to its intriguing photochemical properties. The synthesis of indigo core and available methods for derivatizing indigo are described, serving as synthetic strategies for building desired molecular structures. The photochemical behavior of indigos, particularly E-Z photoisomerization and photoinduced electron transfer, is discussed, emphasizing the connections between molecular structures and photochemical properties as guiding principles for designing indigos as photoresponsive tools.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Wiebke Alex, Patrick Lorenz, Christian Henkel, Timothy Clark, Andreas Hirsch, Dirk M. Guldi
Summary: This study provides a detailed understanding of the full reaction coordinate of NBDs to QCs and reveals that the photoreversibility of NBDs is influenced by the charge-transfer character.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Multidisciplinary
Vaidhyanathan Ramamurthy
Summary: Controlling excited state processes is a long-standing goal in photochemistry. This article summarizes the studies in the author's laboratory using a synthetic reaction container called octa acid, which restricts the dynamics of molecules on an excited state surface.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Arui Huang, Jie Hu, Mengmeng Han, Kangwei Wang, Jian Long Xia, Jiajia Song, Xuelian Fu, Kai Chang, Xiaocong Deng, Siwei Liu, Qianqian Li, Zhen Li
Summary: This study demonstrated multiple photodeformable processes in anil-poly(ethylene terephthalate) systems utilizing excited-state intramolecular proton transfer and trans-cis isomerization as microscopic molecular motions under light stimulus. The doping films were able to achieve light-driven contraction and bending angle during a simple stretching process. The internal mechanism and relationship between molecular structure and photocontrolled motion were investigated through transient absorption spectra, theoretical calculations, and crystal analysis.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Nathalie Zink-Lorre, Sairaman Seetharaman, David Gutierrez-Moreno, Fernando Fernandez-Lazaro, Paul A. Karr, Francis D'Souza
Summary: The study demonstrates photoinduced charge transfer and separation events in a newly synthesized azobenzene-bridged perylenediimide-dimer (PDI-dimer). The fluorescence quenching in the PDI-dimer, especially for the cis isomer, was found to increase with increasing solvent polarity. DFT calculations helped visualize the charge transfer in the PDI-dimer and revealed the involvement of the azobenzene entity in the charge transfer events.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Philipp Pracht, Christoph Bannwarth
Summary: A simplified method based on the non-self-consistent extended tight-binding method GFN0-xTB is presented for describing crossing points between almost arbitrary diabatic states. The method involves only a single diagonalization of the Hamiltonian and can provide energies and gradients for multiple electronic states, which can be used to calculate minimum energy crossing points. The identified geometries are shown to be good starting points for further optimization of minimum energy conical intersections with ab initio methods, based on comparison with high-lying MECIs of benchmark systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Jing Sun, Oriol Vendrell
Summary: The modification of thermal chemical rates in Fabry-Perot cavities presents challenges in theoretical understanding. This study investigates the effect of activated and nonactivated molecules on the reaction rates of gas-phase HONO molecules. It is found that nonactivated molecules enhance energy dissipation, while activated molecules couple with the resonances created by nonactivated molecules and the cavity, resulting in accelerated rates.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Dariusz M. Niedzwiedzki
Summary: Application of femtosecond time-resolved transient absorption spectroscopy revealed new spectroscopic features for the cis isomers of lutein and spirilloxanthin. A distinctive transient absorption band was observed for the central-cis spirilloxanthin, absent in the all-trans isomers. This band could be attributed to a transient cis-peak and could be useful for studying the dynamics of carotenoid isomers.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Dariusz M. Niedzwiedzki
Summary: The application of femtosecond time-resolved transient absorption spectroscopy on two carotenoids, lutein and spirilloxanthin, revealed new spectroscopic features for the cis isomers. A distinct additional transient absorption band was observed in the central-cis spirilloxanthin, absent in the all trans isomers, suggesting it could be assigned to transient cis-peak. This new spectral band could be useful for studying carotenoid isomers and their distorted forms.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Pavel A. Kusochek, Andrei Scherbinin, Anastasia Bochenkova
Summary: Research on the light-driven sodium-pump rhodopsin KR2 revealed the presence of reactive and nonreactive states, exploring the mechanisms through molecular dynamics simulations and large-scale QM/MM modeling. By calculating vibronic band shapes, insights into the early-time excited-state dynamics of PSBR were gained, highlighting the role of the protein environment in facilitating photoisomerization. The study also emphasized the importance of a strong hydrogen bond between the retinal Schiff base and its counterion for ultrafast reaction dynamics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Applied
Maria Joao Melo, Paula Nabais, Marcia Vieira, Rita Araujo, Vanessa Otero, Joao Lopes, Lourdes Martin
Summary: This paper describes an interdisciplinary approach to study heritage materials, highlighting its importance in developing new treatments and innovative strategies for the identification of historical colors in artworks. The authors illustrate their methodology through the study of medieval Islamic manuscripts, showcasing the remarkable properties of ancient dyes and advocating for the sharing of this lost knowledge to empower the community in creating sustainable applications.
Article
Engineering, Electrical & Electronic
Hajer Saadi, Zohra Benzarti, Pedro Sanguino, Joao Pina, Najmeddine Abdelmoula, Joao Sergio Seixas de Melo
Summary: The undoped and Co-doped ZnO nanopowders were synthesized effectively using the chemical co-precipitation process. Various experimental techniques were used to characterize the crystal structure, morphology, vibrational, optical, and dielectric properties of the prepared samples. The study focused on the impact of cobalt doping on the different characteristics of ZnO nanopowders. The results showed that cobalt doping affected the structural, optical, and morphological properties, as well as the dielectric constant and electrical conductivity of the ZnO nanopowders.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Biochemistry & Molecular Biology
Oscar H. Martinez-Costa, Laura Rodrigues-Miranda, Sofia M. Clemente, Antonio Jorge Parola, Nuno Basilio, Alejandro K. Samhan-Arias
Summary: Cytochrome b(5) reductase (Cb5R) is a flavoprotein that participates in redox reactions and generates superoxide anion. Previous studies have shown that different flavonoids can inhibit Cb5R. This study aims to investigate the molecular mechanism of interaction between flavonoids and Cb5R using flavylium salts as dynamic inhibitors.
Article
Biochemistry & Molecular Biology
Maria J. J. Melo, Ana Freitas, Cristiana Vieira, Marcia Vilarigues, Marcia Vieira, Paula Nabais, Silvia Sequeira, Monica Lourenco, Gabriel Oliveira, Ana Rita Correia
Summary: The Natural History and Science Museum of the University of Porto houses a collection of 45 models of fungi in papier-mache from the 19th-century. A study was conducted to examine the materials and techniques used in the production of a Boletus edulis model. This research provides important knowledge for the conservation of these models.
Article
Energy & Fuels
Daniela Pinheiro, Joana F. M. Sousa, Marta Pineiro, Artur J. M. Valente, J. Sergio Seixas De Melo
Summary: Aqueous organic redox flow batteries (AORFBs) were studied using pre-treated or non-pre-treated sulfonated poly(ether ether ketone), SPEEK, membranes and compared with Nafion (R) 115 membrane. It was found that the cells using the non-pre-treated SPEEK membrane showed higher performance and capacity retention. The study highlights the potential of using inexpensive membranes and low-cost active materials in AORFBs.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Chemistry, Applied
Daniela C. Nobre, Estefania Delgado-Pinar, Carla Cunha, Adelino M. Galvao, J. Sergio Seixas de Melo
Summary: Indirubin (INR), a red structural isomer of indigo, exhibits high stability against light due to efficient dark processes dominating the excited state deactivation. The behavior of INR, along with its derivatives, has been studied comprehensively using various techniques. In addition to excited state proton transfer (ESPT) and rotation between indole-like moieties, a new mechanism involving a longer lifetime in a viscous solvent has been observed. These findings provide insights for studying the protective mechanisms in DNA nucleotides and indigoid dyes.
Article
Chemistry, Multidisciplinary
Telma Costa, Mariana Peixoto, Marta Pineiro, J. Sergio Seixas de Melo
Summary: A morphological analysis of different thin films of H2T(TPA)4P was conducted using FLIM and SEM. The study found intramolecular energy transfer in solution, with quenching efficiencies of 94-97%. The morphology of the thin films was highly dependent on the solvent mixture used.
Article
Humanities, Multidisciplinary
Hermine Grigoryan, Marcia Vieira, Paula Nabais, Rita Araujo, Maria J. Melo, Marta Manso, Maria Adelaide Miranda, Jorge Rodrigues
Summary: The illuminated manuscripts at the Gulbenkian Museum were produced in the 17th century by Armenian diaspora in scriptoria. Scientific analysis using fiber-optics reflectance spectroscopy and Raman spectroscopy revealed the use of a medieval palette based on inorganic pigments, as well as the possible use of carminic acid for reds and pinks. The range of colors in the illuminated manuscripts, including lapis lazuli blue and organic reds and pinks, showcases the desire to create exceptional works.
Article
Chemistry, Multidisciplinary
Massimo Tosolini, Chiara Alberoni, Mani Outis, Antonio Jorge Parola, Barbara Milani, Paolo Tecilla, Joao Avo
Summary: This study reports the synthesis of NIs with phosphine and amine chelating moieties and characterizes their optical properties when complexed with Pd(II) ions. It is found that the introduction of phosphine moieties in the naphthalimide core leads to a decrease in emission efficiency and lifetime of these dyes. Complexation with Pd(II) ions results in an optical behavior similar to unsubstituted naphthalimide. Furthermore, the complexation increases the acidity of chelating secondary amines, leading to the formation of a novel naphthalimide dye with a cyclic phosphorylamide moiety.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Applied
Ana Lucia Pinto, Patricia Maximo, Joao Pina, Giuseppe Calogero, Cesar. A. T. Laia, A. Jorge Parola, J. Carlos Lima
Summary: By introducing diethylamino and rigidified julolidine groups into the benzopyrylium core, flavylium derivatives similar to anthocyanins have been explored in dye-sensitized solar cells (DSSCs) with higher efficiency. However, the incorporation of julolidine groups resulted in a decrease in all DSSC parameters, and the self-aggregation processes of julolidine derivatives did not explain the decrease in efficiency. Bridging the benzopyrylium and phenyl rings demonstrated rigidification of flavylium dyes, leading to increased fluorescence quantum yields and a slight improvement in DSSC efficiency.
Article
Electrochemistry
Elin L. Howard, Cesar A. T. Laia, Carlos Pinheiro, A. Jorge Parola
Summary: Electropolymerization triggered inside a pre-assembled device can result in a visually irreversible color change with high contrast. This type of electrochemical indicator holds potential applications in various commercial sectors such as authenticity labeling, healthcare, food packaging, and logistics. A study on the electrochemical polymerization of 3-4-ethylenedioxythiphene (EDOT) in a UV-curable ethylene oxide-propylene oxide-allyl glycidyl ether (EO-PO-AGE) polymer gel electrolyte reveals that the addition of the gel matrix decreases the overpotential required for film formation and improves coloration efficiency and visual homogeneity.
JOURNAL OF APPLIED ELECTROCHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Estefaniia Delgado-Pinar, Matilde Medeiros, Telma Costa, J. Sergio Seixas de Melo
Summary: Chemical derivatives of PEI with either TPA or Cou can form stable complexes with adenine and guanine nucleotides in water based on noncovalent interactions such as pi-pi stacking and hydrogen bonding. PEI-TPA acts as a chemosensor with recognition based on AIE and pi-pi interaction, while the Cou derivative relies on electrostatic interaction. The study provides valuable insights into designing receptors for selective recognition of nucleotides in water.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Chemistry, Physical
Ana Clara B. Rodrigues, Susana M. M. Lopes, Carla Cunha, Joao Braz, Teresa M. V. D. Pinhi e Melo, J. Sergio Seixas de Melo, Marta Pineiro
Summary: A comprehensive study on the electronic spectral, photophysical and acid-base properties of oxime corrole derivatives and model corrole has been performed, aiming to understand their behavior in different states. Solvents and corrole concentration play a vital role in determining the properties of these compounds. The oxime-corroles exhibit solvent-dependent properties and have the potential to be used in biological systems as probes, sensors, or sensitizers for photodynamic therapy.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Jialei Chen-Wu, Patricia Maximo, Patricia Remon, A. Jorge Parola, Nuno Basilio, Uwe Pischel
Summary: The tailored design of a light-triggered supramolecular cascade allows for the transduction of photons into chemical communication and the release of a neurotransmitter, reminiscent of crucial steps in natural vision process.
CHEMICAL COMMUNICATIONS
(2023)
Article
Humanities, Multidisciplinary
Joana Silva, Antonio Jorge Parola, Maria Conceicao Oliveira, Bertrand Lavedrine, Ana Maria Ramos
Summary: Chromogenic reversal films are susceptible to chemical degradation and have poor long-term stability. There is a lack of knowledge regarding chromogenic materials, specifically the dyes used in chromogenic reversal films. A research study focused on the characterization of chromogenic dyes, using various analytical techniques, showed promising results for understanding these materials.
