ORCID Profile
0000-0001-5754-1703
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Publisher: Springer Science and Business Media LLC
Date: 30-05-2023
DOI: 10.1038/S41467-023-38769-Y
Abstract: Exploring approaches to utilize abundant water to synthesize functional molecules and polymers with efficient clusteroluminescence properties is highly significant but has yet to be reported. Herein, a chemistry of water and alkyne is developed. The synthesized products are proven as nonaromatic clusteroluminogens that could emit visible light. Their emission colors and luminescent efficiency could be adjusted by manipulating through-space interaction using different starting materials. Besides, the free-standing polymeric films with much high photoluminescence quantum yields (up to 45.7%) are in situ generated via a water-involved interfacial polymerization. The interfacial polymerization-enhanced emission of the polymeric films is observed, where the emission red-shifts and efficiency increases when the polymerization time is prolonged. The synthesized polymeric film is also verified as a Janus film. It exhibits a vapor-triggered reversible mechanical response which could be applied as a smart actuator. Thus, this work develops a method to synthesize clusteroluminogens using water, builds a clear structure-property relationship of clusteroluminogens, and provides a strategy to in situ construct functional water-based polymeric films.
Publisher: Springer Science and Business Media LLC
Date: 09-03-2020
DOI: 10.1038/S41467-020-15095-1
Abstract: Fluorescence imaging in near-infrared IIb (NIR-IIb, 1500–1700 nm) spectrum holds a great promise for tissue imaging. While few inorganic NIR-IIb fluorescent probes have been reported, their organic counterparts are still rarely developed, possibly due to the shortage of efficient materials with long emission wavelength. Herein, we propose a molecular design philosophy to explore pure organic NIR-IIb fluorophores by manipulation of the effects of twisted intramolecular charge transfer and aggregation-induced emission at the molecular and morphological levels. An organic fluorescent dye emitting up to 1600 nm with a quantum yield of 11.5% in the NIR-II region is developed. NIR-IIb fluorescence imaging of blood vessels and deeply-located intestinal tract of live mice based on organic dyes is achieved with high clarity and enhanced signal-to-background ratio. We hope this study will inspire further development on the evolution of pure organic NIR-IIb dyes for bio-imaging.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8TC02504E
Abstract: A pair of chiral R / S -TPE-BINOL derivatives with dark resonance energy transfer was synthesized using a tetraphenylethylene derivative as a dark energy donor which also endows the target molecules with aggregation-induced emission characteristics, BODIPY as an energy acceptor and BINOL as a chiral source.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2020
DOI: 10.1038/S41467-020-16412-4
Abstract: Organic emitters with persistent phosphorescence have shown potential application in optoelectronic devices. However, rational design and phosphorescence tuning are still challenging. Here, a series of metal-free luminophores without heavy atoms and carbonyl groups from commercial/lab-synthesized carbazole and benzene were synthesized to realize tunable molecular emission from fluorescence to phosphorescence by simply substituent variation. All the molecules emit blue fluorescence in both solution and solid state. Upon removal of excitation source, the fluorinated luminophores show obvious phosphorescence. The lab-synthesized carbazole based molecules exhibit a huge lifetime difference to the commercially purchased ones due to the existence of isomer in the latter s les. The small energy gap between singlet and triplet state and low reorganization energy help enhance intersystem crossing to contribute to a more competitive radiative process from triplet to ground state. Blue and white organic light-emitting devices are fabricated by using fluorinated luminophore as emitting layer.
Publisher: Springer Science and Business Media LLC
Date: 24-06-2023
DOI: 10.1038/S41467-023-39479-1
Abstract: Proximity effect, which refers to the low-lying ( n ,π*) and (π,π*) states with close energy levels, usually plays a negative role in the luminescent behaviors of heterocyclic luminogens. However, no systematic study attempts to reveal and manipulate proximity effect on luminescent properties. Here, we report a series of methylquinoxaline derivatives with different electron-donating groups, which show different photophysical properties and aggregation-induced emission behaviors. Experimental results and theoretical calculation reveal the gradually changed energy levels and different coupling effects of the closely related ( n ,π*) and (π,π*) states, which intrinsically regulate proximity effect and aggregation-induced emission behaviors of these luminogens. With the intrinsic nature of heterocycle-containing compounds, they are utilized for sensors and information encryption with dynamic responses to acid/base stimuli. This work reveals both positive and negative impacts of proximity effect in heterocyclic aggregation-induced emission systems and provides a perspective to develop functional and responsive luminogens with aggregation-induced emission properties.
Publisher: Research Square Platform LLC
Date: 17-01-2023
DOI: 10.21203/RS.3.RS-2465343/V1
Abstract: Water is always used by nature to construct complex species. Learning from nature, the exploration of artificial approaches to utilize abundant water to synthesize functional molecules and polymers with efficient clusteroluminescence properties (CLgens) is highly significant but has yet to be reported. Herein, a new chemistry of water and alkyne was developed. The synthesized products were proved as nonaromatic CLgens that could emit visible light. Their emission colors and luminescent efficiency could be adjusted by manipulating through-space interaction via using different water and alkyne. Besides, the free-standing polymeric films with much high photoluminescence quantum yields (up to 45.7%) were in situ generated via a new H 2 O-involved interfacial polymerization. The interfacial polymerization-induced emission of the polymeric films was observed, where the emission red-shifted and efficiency increased when the polymerization time was prolonged. The synthesized polymeric film was also verified as a "Janus film". It exhibits a vapor-triggered reversible mechanical response which could be applied as a smart actuator. Thus, this work develops a new method to synthesize CLgens using water, builds a clear structure-property relationship of CLgens, and provides a novel strategy to in situ construct functional H 2 O-based polymeric films.
Publisher: AIP Publishing
Date: 08-2019
DOI: 10.1063/1.5110688
Abstract: Interfaces exist in almost all objects and processes. Investigation on the interface not only is fundamentally important but also has great application prospects. Traditionally, the interface structure is studied by electron microscopy, which cannot reflect its real structure considering the pretreated process before measurement. Monitoring the interface evolution process by these regular methods is time-consuming and unfeasible in many cases. In this perspective article, we discuss how to realize the visualizing and monitoring interface structures and dynamics by aggregation-induced emission technique, which is applicable to almost all kinds of interfaces, including gas-solid, liquid-solid, solid-solid, gas-liquid-solid, and liquid-liquid-solid. Meanwhile, it is anticipated that the circularly polarized luminescence property in prochiral aggregation-induced emission luminogens can make a great difference in this area.
Publisher: Wiley
Date: 03-08-2022
Abstract: Dynamic patterns based on luminescent materials play an essential role in the digital age. However, it is still challenging to develop highly emissive photofluorochromic materials with dynamic behaviors to store information with multiple characteristics. Here, we report a series of dihydroazulene‐based compounds which show typical aggregation‐induced emission (AIE) effect. Moreover, the photo‐switching ability of the dihydroazulene units, undergoing light‐induced ring‐opening, enables photofluorochromic properties. The photofluorochromism also shows quantitively described responses to time and temperature via a reverse ring‐closing process. Ultimately, a rewritable 4D information system, embedded with a quick response code, dot matrix with microstructures, color matrix of fluorescence, and time/temperature‐dependent intensity change, is established with dynamic patterns. This work not only develops a dynamic AIE skeleton with photofluorochromic properties but also provides a new strategy for information encryption and cybernetics.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7SC01054K
Abstract: For the first time, an AIEgen-conjugated monoclonal antibody is designed for “turn-on” and “wash-free” imaging of EGFR-overexpressed cancer cells.
Publisher: Wiley
Date: 03-08-2022
Abstract: Dynamic patterns based on luminescent materials play an essential role in the digital age. However, it is still challenging to develop highly emissive photofluorochromic materials with dynamic behaviors to store information with multiple characteristics. Here, we report a series of dihydroazulene‐based compounds which show typical aggregation‐induced emission (AIE) effect. Moreover, the photo‐switching ability of the dihydroazulene units, undergoing light‐induced ring‐opening, enables photofluorochromic properties. The photofluorochromism also shows quantitively described responses to time and temperature via a reverse ring‐closing process. Ultimately, a rewritable 4D information system, embedded with a quick response code, dot matrix with microstructures, color matrix of fluorescence, and time/temperature‐dependent intensity change, is established with dynamic patterns. This work not only develops a dynamic AIE skeleton with photofluorochromic properties but also provides a new strategy for information encryption and cybernetics.
Publisher: Springer Science and Business Media LLC
Date: 02-09-2023
Publisher: Wiley
Date: 13-01-2023
Abstract: Photoswitches with multiple fluorescence states known as photofluorochromism upon photo‐induced isomerization show practical applications in information storage, anticounterfeiting, and sensors. However, it is still challenging to realize rapid isomerization, efficient fluorescence, and gradient signal output simultaneously. Herein, by incorporating luminogenic units with aggregation‐induced emission (AIE) features into photo‐responsive hydrazone, a series of novel photofluorochromic AIE compounds are developed. These newly designed compounds exhibit quantum yields of up to 38.4% and could undergo reversible and swift photo‐isomerization upon 450/365 nm irradiation. Accordingly, the fabricated photopatterns based on them are utilized as quantitatively described images for information storage, which show excellent rewritability and intensity‐variable fluorescence with a high resolution of 10 µm. This work provides a new strategy to develop intelligent photopattern systems with continuous gradient fluorescence for information storage and cybernetics.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9QM00242A
Abstract: Berberine chloride, an AIE-active natural product, can be utilized as a highly efficient theranostic agent for cancer and bacteria.
Publisher: Wiley
Date: 21-05-2022
Abstract: Liquid‐liquid phase separation (LLPS) drives membraneless organelles (MLOs) formation for organizing biomolecules. Artificial MLOs (AMLOs) have been constructed mostly via the LLPS of engineered proteins capable of regulating limited types of biomolecules. Here, leveraging a minimalist AMLO, driven by LLPS of polymer‐oligopeptide hybrids, enrichment, recruitment, and release of multifaceted cargoes are quantitatively shown, including small fluorescent molecules, fluorophore‐containing macromolecules, proteins, DNAs, and RNAs. Cargoes show up to 10 5 ‐fold enrichment, whilst recruitment and release are triggered by variations of temperature, pH, and/or ionic strength. Also, the first efficacious, rapid, and reversible control of aggregation‐induced emission with over 30 folds of modulation of overall fluorescence intensity is achieved, by intensifying the aggregation of luminogens in AMLO. The AMLO is a simple yet versatile platform for potential drug delivery and biosensor applications.
Publisher: Springer Science and Business Media LLC
Date: 02-12-2022
DOI: 10.1038/S41467-022-35155-Y
Abstract: Developing dynamic organic ultralong room-temperature phosphorescent (URTP) materials is of practical importance in various applications but remains a challenge due to the difficulty in manipulating aggregate structures. Herein, we report a dish-like molecular architecture via a bottom-up way, featuring guest-responsive dynamic URTP. Through controlling local fragment motions in the molecular architecture, fascinating dynamic URTP performances can be achieved in response to reversible accommodation of various guests, including solvents, alkyl bromides and even carbon dioxide. Large-scale regulations of phosphorescence lifetime (100-fold) and intensity (10-fold) can be realized, presenting a maximum phosphorescence efficiency and lifetime of 78.8% and 483.1 ms, respectively. Moreover, such a dish-like molecular architecture is employed for temperature-dependent multiple information encryption and visual identification of linear alkyl bromides. This work can not only deepen our understanding to construct multifunctional organic aggregates, but also facilitate the design of high-performance dynamic URTP materials and enrich their practical applications.
Publisher: Wiley
Date: 20-03-2019
Abstract: The efficient utilization of energy dissipating from non-radiative excited-state decay of fluorophores was only rarely reported. Herein, we demonstrate how to boost the energy generation of non-radiative decay and use it for cancer theranostics. A novel compound (TFM) was synthesized which possesses a rotor-like twisted structure, strong absorption in the far red/near-infrared region, and it shows aggregation-induced emission (AIE). Molecular dynamics simulations reveal that the TFM aggregate is in an amorphous form consisting of disordered molecules in a loose packing state, which allows efficient intramolecular motions, and consequently elevates energy dissipation from the pathway of thermal deactivation. These intrinsic features enable TFM nanoparticles (NPs) to display a high photothermal conversion efficiency (51.2 %), an excellent photoacoustic (PA) effect, and effective reactive oxygen species (ROS) generation. In vivo evaluation shows that the TFM NPs are excellent candidates for PA imaging-guided phototherapy.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7SC04963C
Abstract: The first water-soluble NIR AIEgen was synthesized and used for ultrafast wash-free cellular imaging and photodynamic cancer cell ablation.
Publisher: Research Square Platform LLC
Date: 31-03-2023
DOI: 10.21203/RS.3.RS-2690391/V1
Abstract: We report the construction of covalent organic framework (COF-919) from planar and twisted AIEgens-based motifs as a pyroptosis and ferroptosis dual-inducer that can elicit strong inflammatory response for efficient antitumor immunity. Mechanistic studies revealed that, in contrast to traditional COFs constructed with solely planar or twisted motifs, COF-919 displays stronger near-infrared light absorption, lower band energy and longer lifetime to favor the reactive oxygen species (ROS) generation and photothermal conversion for trigger pyroptosis. Because of its outstanding ROS production capability, intracellular lipid peroxidation was also upregulated to lead to glutathione depletion, glutathione peroxidase 4 low expression, and the induction of ferroptosis. Moreover, COF-919 induced pyroptosis and ferroptosis can effectively reshape the tumor immune microenvironment (TME) via promote T cells infiltration and relieve immunosuppressed TME to boost a T-cell-mediated immune response, which is favorable for inhibiting tumor metastasis and recurrence, with 99% tumor growth inhibition and 80% cure rates.
Publisher: Wiley
Date: 20-03-2019
Publisher: Springer Science and Business Media LLC
Date: 11-02-2021
DOI: 10.1038/S41467-021-21208-1
Abstract: Nitric oxide (NO) is an important signaling molecule overexpressed in many diseases, thus the development of NO-activatable probes is of vital significance for monitoring related diseases. However, sensitive photoacoustic (PA) probes for detecting NO-associated complicated diseases (e.g., encephalitis), have yet to be developed. Herein, we report a NO-activated PA probe for in vivo detection of encephalitis by tuning the molecular geometry and energy transformation processes. A strong donor-acceptor structure with increased conjugation can be obtained after NO treatment, along with the active intramolecular motion, significantly boosting “turn-on” near-infrared PA property. The molecular probe exhibits high specificity and sensitivity towards NO over interfering reactive species. The probe is capable of detecting and differentiating encephalitis in different severities with high spatiotemporal resolution. This work will inspire more insights into the development of high-performing activatable PA probes for advanced diagnosis by making full use of intramolecular motion and energy transformation processes.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8SC01709C
Abstract: This article presents a new strategy to achieve white-light emission from single tetraphenylethylene-substituted pyrenes (TPE-Pys) with aggregation-induced emission (AIE) characteristics.
Publisher: Wiley
Date: 05-05-2023
Abstract: Recent advancements in aggregation‐induced emission (AIE) macromolecular materials have brought their attention as potential antibacterial solutions, these materials offer new approaches to cure multidrug‐resistant infections and biofilms in bacterial infections as well as real‐time monitoring and specific targeting of bacteria. This review provides an overview of the three main categories of AIE macromolecular materials with antibacterial properties namely AIE‐active polymers, AIEgen@polymer complexes, and clusterization‐triggered emission (CTE) based polymers. The mechanisms and applications of these materials in antibacterial treatment, wound care, and protective equipment are also discussed. The potential for future developments and application directions of AIE‐based antimicrobial materials are finally highlighted.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8SC05805A
Abstract: Facile synthesis and bio-applications of a series of AIEgens with widely tunable emissions ranging from violet to near-infrared are reported.
No related grants have been discovered for Wing Yip Lam.