A novel mesoporous nanosheet networked hybrid comprising Co3O4 and Co3(PO4)2 is successfully synthesized using a facile and scalable method through calcinating the carbon, cobalt hydroxy carbonate, ...and cobalt phosphate composite precursor. Electron transfer from Co3O4 to Co3(PO4)2, together with the special networked structure and the porous nature of the nanosheets enable the Co3(PO4)2‐Co3O4 hybrid to have a high oxygen evolution reaction (OER) activity and outstanding stability in alkaline electrolyte, e.g., an overpotential of 270 mV at current density of 10 mA cm−2, and a Tafel slope of 39 mV dec−1, which are superior to most non‐noble metal‐based OER electrocatalysts reported thus far and as well the commercial RuO2 electrocatalyst. Furthermore, Co3(PO4)2‐Co3O4 hybrid is demonstrated to be used as an efficient cocatalyst to enhance the photoelectrochemical OER performance of BiVO4 photoanode. A significantly increased photocurrent density of 3.0 mA cm−2 at 1.23 V (vs reversible hydrogen electrode, RHE), and a potential reduction of 530 mV with respect to that of bare BiVO4 at the photocurrent density of 0.5 mA cm−2 are achieved. The electron transfer‐induced enhancement of OER by a hybrid structure may pave the new routes for the design and synthesis of low‐cost catalysts for electrochemical and photoelectrochemical oxygen evolution.
A novel networked mesoporous nanosheet hybrid composed of Co3O4 and Co3(PO4)2 is synthesized through calcinating the carbon, cobalt hydroxy carbonate, and cobalt phosphate composite precursor. Beneficial from the collective effects of special morphological design and the synergistic enhancement effect between ingredients, the Co3(PO4)2‐Co3O4 nanocomposite exhibits very high activities and excellent stabilities for the electrochemical and photoelectrochemical oxygen evolution reaction.
A facile approach for the preparation of supramolecular polymer‐based fluorescent nanoparticles (FNPs) is reported. FNPs with homogeneous shape and size distribution are fabricated from ...low‐molecular‐weight molecules, and thus, different compositional constituents can be efficiently incorporated via copolymerization. The emission color of the FNPs covers a wide region from blue to near infrared and can be easily tuned using efficient excitation energy transfer. The photoswitchable fluorescent nanoparticles with high on–off fluorescence contrast are also simply prepared by copolymerization of monomers containing a fluorophore and a photochromic unit. Our FNPs are successfully applied in living cell imaging and as fluorescent inks.
A new set of fluorescent nanoparticles (FNPs) are fabricated from hydrogen‐bonded supramolecular polymers. Their preparation is straightforward, and nanoparticles with homogeneous shape and size are obtained. The emission color of the FNPs covers a wide region from blue to near infrared and is easily tunable by excitation energy transfer. These FNPs are successfully used in bioimaging and as fluorescent inks.
Type‐I photosensitizers (PSs) can generate free radical anions with a broad diffusion range and powerful damage effect, rendering them highly desirable in various areas. However, it still remains a ...recognized challenge to develop pure Type‐I PSs due to the inefficiency in producing oxygen radical anions through the collision of PSs with nearby substrates. In addition, regulating the generation of oxygen radical anions is also of great importance toward the control of photosensitizer (PS) activities on demand. Herein, a piperazine‐based cationic Type‐I PS (PPE‐DPI) that exhibits efficient intersystem crossing and subsequently captures oxygen molecules through binding O2 to the lone pair of nitrogen in piperazine is reported. The close spatial vicinity between O2 and PPE‐DPI strongly promotes the electron transfer reaction, ensuring the exclusive superoxide radical (O2•−) generation via Type‐I process. Particularly, PPE‐DPI with cationic pyridine groups is able to associate with cucurbit7uril (CB7) through host‐guest interactions. Thus, supramolecular assembly and disassembly are easily utilized to realize switchable O2•− generation. This switchable Type‐I PS is successfully employed in photodynamic antibacterial control.
Switchable Type‐I photosensitizer generated superoxide radical exclusively is constructed based on O2‐capture‐based electron transfer and supramolecular assembly for photodynamic antibacterial control.
The first example of a ratiometric optical oxygen nanoprobe based on a hydrogen‐bonded supramolecular polymer has been reported. The supramolecular polymer based nanoprobe (SPNP) is prepared from the ...co‐assembly of a bis‐ureidopyrimidinone (bis‐UPy)‐containing phosphorescent indicator (Por(Pd)‐bisUPy), fluorescent reference dye (BF2‐bisUPy), and skeleton unit (DPA‐bisUPy) through quadruple hydrogen bonds by a mini‐emulsion method. The water‐dispersible SPNP is highly sensitive to oxygen (Q = 95%), with full reversibility, excellent storage stability and photostability, and good cell‐penetrating ability, and exhibits low cytotoxicity toward living cells. The preparation of the SPNP is straightforward and its function is easily tuned by changing the monomeric structure. This work is expected to lead to the design of other SPNPs for other important analytes in biological systems.
The first water‐dispersible supramolecular‐polymer‐based ratiometric oxygen nanoprobe (SPNP) is reported. The preparation of the SPNP is straightforward and its function is easily tuned by changing the monomeric structures. The SPNP is highly sensitive to oxygen, with full reversibility, excellent storage stability and photostability, and good cell‐penetrating ability, and exhibit low cytotoxicity toward living cells.
Fungal infection poses and increased risk to human health. Photodynamic therapy (PDT) as an alternative antifungal approach garners much interest due to its minimal side effects and negligible ...antifungal drug resistance. Herein, we develop stereoisomeric photosensitizers ((Z)- and (E)-TPE-EPy) by harnessing different spatial configurations of one molecule. They possess aggregation-induced emission characteristics and ROS, viz.
O
and O
generation capabilities that enable image-guided PDT. Also, the cationization of the photosensitizers realizes the targeting of fungal mitochondria for antifungal PDT killing. Particularly, stereoisomeric engineering assisted by supramolecular assembly leads to enhanced fluorescence intensity and ROS generation efficiency of the stereoisomers due to the excited state energy flow from nonradiative decay to the fluorescence pathway and intersystem (ISC) process. As a result, the supramolecular assemblies based on (Z)- and (E)-TPE-EPy show dramatically lowered dark toxicity without sacrificing their significant phototoxicity in the photodynamic antifungal experiments. This study is a demonstration of stereoisomeric engineering of aggregation-induced emission photosensitizers based on (Z)- and (E)-configurations.
Organic near-infrared (NIR) emitters hold great promise for biomedical applications. Yet, most organic NIR fluorophores face the limitations of short emission wavelengths, low brightness, ...unsatisfactory processability, and the aggregation-caused quenching effect. Therefore, development of effective molecular design strategies to improve these important properties at the same time is a highly pursued topic, but very challenging. Herein, aggregation-induced emission luminogens (AIEgens) are employed as substituents to simultaneously extend the conjugation length, boost the fluorescence quantum yield, and increase the solubility of organic NIR fluorophores, being favourable for biological applications. A series of donor-acceptor type compounds with different substituent groups (
i.e.
, hydrogen, phenyl, and tetraphenylethene (TPE)) are synthesized and investigated. Compared to the other two analogs,
MTPE-TP3
with TPE substituents exhibits the reddest fluorescence, highest brightness, and best solubility. Both the conjugated structure and twisted conformation of TPE groups endow the resulting compounds with improved fluorescence properties and processability for biomedical applications. The
in vitro
and
in vivo
applications reveal that the NIR nanoparticles function as a potent probe for tumour imaging. This study would provide new insights into the development of efficient building blocks for improving the performance of organic NIR emitters.
AIEgens are exploited to simultaneously extend the conjugation, boost the brightness, and increase the solubility of organic near-infrared fluorophores, representing a new strategy for developing high-performance emitters for biomedical imaging.
Supramolecular architectures are constructed by the self‐assembly of small building blocks via the use of metal‐ligand coordination, π–π stacking interactions, hydrogen bonding, host‐guest ...interactions, and other noncovalent driving forces, which confer unique dynamic reversibility and stimulus responsiveness to the supramolecular materials and also lead to the demand of expensive and complex equipment for the characterization of supramolecular assembly processes. Fortunately, the self‐assembly processes bring the monomeric chromophores together, offering possibilities to establish ties between the supramolecular assembly and aggregation‐induced emission (AIE) techniques. Compared to conventional luminescent molecules, AIE luminogens (AIEgens) exhibit significant fluorescence enhancement upon the restriction of molecular motions, thus displaying the advantages of signal amplification and low background noises. Given the above, the real‐time, sensitive, and in situ visualization of the formation of self‐assemblies and their stimuli responsiveness based on AIE becomes accessible. Here, we review recent works that encompass the visualization of supramolecular assembly‐related behaviors by means of AIE characteristics of chromophores. The organization of this review will be by different types of supramolecular architectures, including metallacycles/cages, micelles/vesicles, supramolecular polymers, and supramolecular gels. An overview of future opportunities and challenges for the real‐time monitoring of supramolecular assembly by AIE is also provided.
Given the advantages of aggregation‐induced emission (AIE), the real‐time, sensitive, and in situ visualization of the formation of self‐assemblies and their stimuli responsiveness is accessible. Here, we review recent advances in the visualization of supramolecular assembly processes and their further dynamic behaviors by AIE techniques. The types of supramolecular structures in this review include metallacycles/cages, micelles/vesicles, supramolecular polymers, and supramolecular gels.
A good harvest: Two self‐assembling strategies (micellization and electrostatic attraction) and covalent capture were employed to construct a robust, inexpensive, efficient artificial ...light‐harvesting system (see picture). The synthesis was achieved by a one‐pot reaction. A high density of the antenna chromophores was achieved without self‐quenching and excimer formation, thus affording extremely efficient energy transfer.
The advance of the synthesis of ammonia through nitrogen electroreduction under ambient conditions is seriously impeded by the lack of an efficient electrocatalyst that can facilitate multiple ...proton-coupled electron-transfer processes and suppress the competitive hydrogen evolution reaction required for a high nitrogen reduction reaction (NRR) selectivity. Herein, we demonstrate for the first time that boron-doped and nanostructured diamond can be used as an electrocatalyst for NRR, which affords a high NH3 yield rate of 19.1 μg h–1 cm–2, a Faradaic efficiency as high as 21.2%, and a stable operation of at least 8 days under ambient conditions. Substitutional boron atoms are illustrated to be capable of initiating the NRR active centers, and charge accumulation on the nanostructured diamond surface enables further enhancement of catalytic activity through reducing the reaction free energy for the rate-determining step of the NRR on certain surfaces.
The incidence and mortality rates of skin melanoma have been increasing annually. Photodynamic therapy (PDT) enables effective destruction of tumor cells while minimizing harm to normal cells. ...However, traditional photosensitizers (PSs) suffer from photobleaching, photodegradation and the aggregation-caused quenching (ACQ) effect, and it is challenging for light to reach the deep layers of the skin to maximize the efficacy of PSs. Herein, we developed dissolving microneedles (MNs) loaded with PSs of TPE-EPy@CB7 through supramolecular assembly. The PSs effectively enhanced the type-I reactive oxygen species (ROS) generation capacity, with a concentration of 2 μM possessing nearly half of the tumor cell-killing ability under 10 min white light irradiation. The MNs were successfully pierced into the targeted site for precise drug delivery. Additionally, the conical structure of the MNs, as well as the lens-like structure after dissolution, facilitated the transmission of light in the subcutaneous tissue, achieving significant inhibition of tumor growth with a tumor suppression rate of 97.8% and no systemic toxicity or side effects in melanoma mice. The results demonstrated the potent melanoma inhibition and biosafety of this treatment approach, exhibiting a new and promising strategy to conquer malignant melanoma.
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