Article
Chemistry, Inorganic & Nuclear
Guang-Xi Xu, Lawrence Cho-Cheung Lee, Cyrus Wing-Ching Kwok, Peter Kam-Keung Leung, Jing-Hui Zhu, Kenneth Kam-Wing Lo
Summary: A series of rhenium(I) polypyridine complexes with 2,4-dinitrophenylsulfonamide (DNPS) units were synthesized and characterized for their phosphorogenic bioimaging and photocytotoxic properties. The complexes exhibited weak luminescence upon photoexcitation due to photoinduced electron transfer, but showed enhanced emission and potent photocytotoxicity after reaction with glutathione (GSH) in living cells. Additionally, modification with a tosylamide unit enabled the complexes to selectively target the endoplasmic reticulum (ER) for bioimaging and photocytotoxic applications.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Markus Hecht, Frank Wurthner
Summary: The discovery of the self-assembly of cyanine dyes into J-aggregates had a significant impact on dye chemistry, leading to the emergence of new useful properties. Despite a good theoretical understanding of their structure-property relationships, examples of J-aggregates remained scarce due to the lack of supramolecular designs to guide their formation. The use of nature's supramolecular blueprint in the development of J-aggregates of perylene bisimides (PBIs) has shown promise in various applications, such as high-performance color pigments and organic semiconductors.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Review
Chemistry, Multidisciplinary
Xiaotong Shen, Wei Xu, Jin Ouyang, Na Na
Summary: Fluorescence resonance energy transfer (FRET) combined with nanomaterials holds great potential for precise measurements in biological systems.
CHINESE CHEMICAL LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Nataliia Shtemenko, Isabel Pont, Yuliia Husak, Alexander Golichenko, Salvador Blasco, Alexander Shtemenko, Enrique Garcia-Espana
Summary: The synthesis of four dirhenium(III) cis-dicarboxylates with the alpha-amino acids residues Asp (I), Glu (II), Phe (III) and Tyr (IV) was presented. The evaluation of their G-quadruplex stabilization potential by fluorescence resonance energy transfer - melting analysis showed specific binding to c-kit1 quadruplex and strong stabilization activity to HTelo21 quadruplex. These compounds did not show any stabilization activity for ds26 DNA, indicating unique mechanisms of molecular DNA recognition for these complexes.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2021)
Article
Chemistry, Physical
Chris Rehhagen, Shahnawaz Rafiq, Kyra N. Schwarz, Gregory D. Scholes, Stefan Lochbrunner
Summary: Exciton migration is a crucial process for light harvesting in organic systems, but it is often hindered by the formation of trap states. In this study, the mobility of singlet and excimer excitons in nanoparticles made of perylene bisimide molecules was compared. The results showed that the mobility of excimer excitons can be higher than that of singlet excitons, and it is influenced by the intermolecular electronic coupling.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Amr Ghazy, Jonas Ylonen, Nagarajan Subramaniyam, Maarit Karppinen
Summary: We have developed a novel atomic/molecular layer deposition (ALD/MLD) process for europium-organic thin films using Eu(thd)3 and 2-hydroxyquinoline-4-carboxylic acid (HQA) precursors. The resulting Eu-HQA thin films demonstrate high growth rate and exhibit red Eu3+ luminescence with extended excitation wavelength range up to about 400 nm, attributed to the sensitizer role of organic HQA. These films are further deposited on nanoplasmonic structures to achieve twentyfold enhanced emission intensity. Moreover, we demonstrate the potential of Eu-HQA coated nanoplasmonic structures in novel bioimaging applications through FRET-type energy transfer process with commercial Alexa647 fluorophor.
Article
Chemistry, Applied
Ashton N. Bartley, Sadie F. Depeter, Ronald K. Castellano
Summary: This article reports the preparation and photophysical investigation of the first molecular multi-FRET system from the benzotrifuranone (BTF) scaffold. The target molecule was synthesized using a step-conservative approach, incorporating three optically complementary chromophores. The study demonstrates high energy transfer efficiency and significant pseudo-Stokes shift in the fluorescence emission of the target. The design has potential applications in material science and life sciences.
Article
Chemistry, Physical
Trevor A. Smith, Rohan J. Hudson, Anjay Manian, Christopher R. Hall, Timothy W. Schmidt, Salvy P. Russo, Kenneth P. Ghiggino
Summary: Gating logical operations through high-lying excited states of perylene has potential for the development of ultrafast, subnanometer computational devices. This study uses femtosecond spectroscopy and quantum chemical calculations to investigate the relaxation dynamics of monomeric perylene's higher electronic excited states. The obtained lifetimes of the 2(1)Ag and 2(1)B(2u) states suggest that these states could be useful for logical operations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Biochemistry & Molecular Biology
Shruti Vig, Brandon Gaitan, Lucas Frankle, Yu Chen, Rosalie Elespuru, T. Joshua Pfefer, Huang-Chiao Huang
Summary: Currently, various fluorescence imaging agents are being studied in clinical trials. However, phototoxicity poses a challenge to the clinical application of fluorophores. Existing guidelines on medication-based phototoxicity mainly focus on the skin effects during sun exposure, but the use of fluorophores in intraoperative imaging procedures may lead to photochemical damage to deeper tissues. Therefore, it is necessary to have independent knowledge on phototoxicity to facilitate the development of fluorescence imaging products.
PHOTOCHEMISTRY AND PHOTOBIOLOGY
(2023)
Article
Multidisciplinary Sciences
Ningning Tang, Jiadong Zhou, Liangxuan Wang, Matthias Stolte, Guojing Xie, Xinbo Wen, Linlin Liu, Frank Wuethner, Johannes Gierschner, Zengqi Xie
Summary: Nano-sized PBI dyes achieve deep-red emission and avoid common quenching pathways by tuning the dihedral angle between the aromatic and alkoxy groups.
NATURE COMMUNICATIONS
(2023)
Review
Chemistry, Analytical
Yuexin Wu, Tianyu Jiang
Summary: This article provides an overview of recent progress in FRET- and BRET-based biosensors and their roles in biomedicine, environmental applications, and synthetic biology. It highlights the importance of FRET and BRET-based biosensors, and provides examples of their design strategies and applications. The limitations of their applications and future directions of development are also discussed.
Article
Chemistry, Applied
Jifu Sun, Mingmei Shu, Ningyuan Wang, Qun Wang, Huaiman Cao, Xue Zhang, Bo Wang, Jianzhang Zhao
Summary: The intensity of host-guest interactions plays a crucial role in FRET/TTET processes based on fluorophore-functionalized pillararenes. Changing the polarity and size of solvents affects the strength of the interactions, leading to variations in the efficiency of FRET/TTET.
Article
Chemistry, Multidisciplinary
Yongseok Hong, Felix Schlosser, Woojae Kim, Frank Wurthner, Dongho Kim
Summary: This study presents the mechanism of ultrafast photoinduced symmetry-breaking charge separation (SB-CS) in a 1,7-bis(N-pyrrolidinyl) PBI dimer within a cyclophane. The authors demonstrate that ultrafast SB-CS in the dimer is enabled by the combination of vibrationally coherent charge-transfer resonance-enhanced excimer formation and breakdown of adiabaticity in the excimer state via structural and solvent fluctuation. Quantum chemical calculations support the crucial role of strong electron donating substituents in triggering the ultrafast SB-CS.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Chaochao Qin, Zheng Zhang, Qiaoling Xu, Jian Song, Zhaoyong Jiao, Shuhong Ma, Ruiping Qin, Yuhai Jiang
Summary: A J-type dimer PMI-2 was studied to investigate its excited-state dynamics. The results showed that a symmetry-breaking charge separation process in PMI-2 is mediated by a mixed excimer, which is a combination of localized Frenkel excitation and interunit charge transfer states. The transformation from a mixed state to the charge transfer state was found to be accelerated with increasing solvent polarity, accompanied by a significant reduction in the recombination time. Theoretical calculations revealed that these changes were attributed to the more negative free energy and lower energy levels of the charge transfer state in highly polar solvents. Our findings highlight the solvent-dependent charge separation process in J-type dimers.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Applied
Xin Zhang, Beibei Wang, Zhiyu Zheng, Guiqiang Yang, Chao Zhang, Liqiong Liao
Summary: This study developed a durable poly(vinyl alcohol) hydrogel with photo-switchable fluorescence properties by incorporating dual-color fluorescent nanoparticles. The hydrogel exhibited different fluorescence emission peaks under UV and visible light, and demonstrated pH responsive fluorescence behavior. It could be used as dual-color building blocks to construct various structures.
Article
Chemistry, Inorganic & Nuclear
Jing-Hui Zhu, Shek-Man Yiu, Ben Zhong Tang, Kenneth Kam-Wing Lo
Summary: Novel neutral iridium(III) complexes with cubic polyhedral oligomeric silsesquioxane (POSS) units were designed, providing promising luminescent probes for lipid droplets through structural modification.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Alex Man-Hei Yip, Calvin Kin-Ho Lai, Ken Shek-Man Yiu, Kenneth Kam-Wing Lo
Summary: 1,2,4,5-tetrazine functions as both a bioorthogonal reactive unit and a luminescence quencher, making it a desirable candidate for luminogenic labeling in living systems. This study synthesized and characterized three cyclometalated iridium(III) complexes with two tetrazine units, which exhibited high reaction kinetics towards specific substrates, allowing effective peptide labeling. These complexes were also applied for live cell bioimaging and photocytotoxicity, and one of them was used to prepare luminescent nanosized hydrogels with interesting cargo delivery properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Lawrence Cho-Cheung Lee, Kenneth Kam-Wing Lo
Summary: There has been a growing interest in utilizing the photophysical and photochemical properties of transition metal complexes for diagnostic and therapeutic applications. This Perspective highlights the recent advances in developing luminescent and photofunctional transition metal complexes, particularly those of rhenium(I), ruthenium(II), osmium(II), iridium(III), and platinum(II) as bioimaging reagents and phototherapeutic agents. The focus is on molecular design strategies that harness and modulate the interesting photophysical and photochemical behavior of these complexes. The current challenges and future outlook of transition metal complexes for both fundamental research and clinical applications are also discussed.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Multidisciplinary
Lawrence Cho-Cheung Lee, Kenneth Kam-Wing Lo
Summary: The rapid development of responsive fluorescent probes has advanced optical imaging for biological research and biomedical applications. Activity-based sensing is a promising strategy for the development of responsive probes for selective molecular imaging. Luminescent transition metal complexes have remarkable photophysical behavior and have been widely used for bioimaging and biosensing applications, especially as activity-based probes for detecting chemical species and bioactive molecules.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Review
Chemistry, Inorganic & Nuclear
Lawrence Cho-Cheung Lee, Lili Huang, Peter Kam-Keung Leung, Kenneth Kam-Wing Lo
Summary: Peptides are ideal for diagnostic and therapeutic applications due to their small size, ease of synthesis, high affinity, and low immunogenicity. Photofunctional transition metal complexes have gained significant interest as cellular probes, bioimaging reagents, and therapeutic agents, owing to their unique photophysical and photochemical properties. This review summarizes recent advances in the development of photofunctional transition metal-peptide conjugates for bioimaging and therapeutic applications, with a focus on their cellular uptake, intracellular localization, and cytotoxic activity. The challenges and future prospects of these conjugates as diagnostic and therapeutic tools are also discussed.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Editorial Material
Chemistry, Inorganic & Nuclear
Kenneth Kam-Wing Lo
Summary: Inorganic chemistry research in Hong Kong has made impressive progress and gained worldwide recognition. This Guest Editorial introduces the research conducted in seven universities: City University of Hong Kong (CityU), The Chinese University of Hong Kong (CUHK), The Education University of Hong Kong (EdUHK), Hong Kong Baptist University (HKBU), The University of Hong Kong (HKU), The Hong Kong University of Science and Technology (HKUST), and The Hong Kong Polytechnic University (PolyU).
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Justin Shum, Lawrence Cho-Cheung Lee, Michael Wai-Lun Chiang, Yun-Wah Lam, Kenneth Kam-Wing Lo
Summary: This article reports a novel targeting strategy that combines an enzyme-instructed self-assembly (EISA) moiety and a strained cycloalkyne to create bioorthogonal sites in cancer cells. These sites can serve as triggers for activation of transition metal-based probes, specifically new ruthenium(II) complexes with a tetrazine unit, enabling controllable phosphorescence and singlet oxygen generation. The study also demonstrates that the hydrophobic regions provided by the large supramolecular assemblies further enhance the environment-sensitive emission of the complexes, making them highly advantageous for biological imaging. Additionally, the (photo)cytotoxicity of the large supramolecular assemblies containing the complexes was investigated, with results showing that cellular localization (extracellular and intracellular) significantly impacts the efficiency of the photosensitizers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Editorial Material
Chemistry, Multidisciplinary
Stefanie Dehnen, Jonathan W. Steed, Kenneth Lo, Katja Heinze, Oliver S. Wenger, Shalini Singh, Hai-Bo Yang, Shuang-Quan Zang
CRYSTAL GROWTH & DESIGN
(2023)
Editorial Material
Chemistry, Inorganic & Nuclear
Stefanie Dehnen, Jonathan W. Steed, Kenneth Lo, Katja Heinze, Oliver S. Wenger, Shalini Singh, Hai-Bo Yang, Shuang-Quan Zang
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Lijuan Hua, Kenneth Yin Zhang, Hua-Wei Liu, Kin-Shing Chan, Kenneth Kam-Wing Lo
Summary: We report the design, synthesis, and characterisation of a series of luminescent iridium(iii) porphyrin complexes. The complexes exhibited long-lived near-infrared (NIR) emission and showed cytotoxic activity towards HeLa cells. Cellular uptake studies indicated that the cationic complexes had higher uptake efficiency. Additionally, a carboxyl complex was used to label a model protein and showed similar photophysical properties and intracellular localization behavior.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Guang-Xi Xu, Lawrence Cho-Cheung Lee, Peter Kam-Keung Leung, Eunice Chiu-Lam Mak, Justin Shum, Kenneth Yin Zhang, Qiang Zhao, Kenneth Kam-Wing Lo
Summary: In this study, a bioorthogonal dissociative photosensitizer based on rhenium(i) polypyridine complexes was designed for the controlled induction of immunogenic cell death. The photosensitizer exhibited increased emission intensities and singlet oxygen generation efficiencies upon reaction with trans-cyclooct-4-enol, leading to enhanced cytotoxic activity towards tumor cells and the induction of a cascade of biological effects including lysosomal dysfunction, autophagy suppression, and immunogenic cell death.
Article
Chemistry, Multidisciplinary
Lili Huang, Peter Kam-Keung Leung, Lawrence Cho-Cheung Lee, Guang-Xi Xu, Yun-Wah Lam, Kenneth Kam-Wing Lo
Summary: We report the development of near-infrared (NIR)-emitting cyclometallated iridium(iii) complexes containing a heteroaromatic methylsulfone moiety as sulfhydryl-specific reagents. One of the complexes was conjugated to cysteine and cysteine-containing peptides and proteins for bioimaging and photocytotoxic applications.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Peter Kam-Keung Leung, Lawrence Cho-Cheung Lee, Herman Ho-Yin Yeung, Kai-Wa Io, Kenneth Kam-Wing Lo
Summary: In this study, bioorthogonal control of the phosphorescence and singlet oxygen photosensitisation properties of new iridium(iii) tetrazine complexes was demonstrated using different reaction partners. This system was utilized for organelle-specific staining and modulated photocytotoxic activity applications.
CHEMICAL COMMUNICATIONS
(2021)
