New agents with particular specificity toward targeted bacteria and superefficacy in antibacterial activity are urgently needed in facing the crisis of worldwide antibiotic resistance. Herein, a ...novel strategy by equipping bacteriophage (PAP) with photodynamic inactivation (PDI)-active AIEgens (luminogens with aggregation-induced emission property) was presented to generate a type of AIE–PAP bioconjugate with superior capability for both targeted imaging and synergistic killing of certain species of bacteria. The targeting ability inherited from the bacteriophage enabled the bioconjugates to specifically recognize the host bacteria with preserved infection activity of phage itself. Meanwhile, the AIE characteristic empowered them a monitoring functionality, and the real-time tracking of their interactions with targets was therefore realized via convenient fluorescence imaging. More importantly, the PDI-active AIEgens could serve as powerful in situ photosensitizers producing high-efficiency reactive oxygen species (ROS) under white light irradiation. As a result, selective targeting and synergistic killing of both antibiotic-sensitive and multi-drug-resistant (MDR) bacteria were successfully achieved in in vitro and in vivo antibacterial tests with excellent biocompatibility. This novel AIE–phage integrated strategy would diversify the existing pool of antibacterial agents and inspire the development of promising drug candidates in the future.
In this work, we demonstrate a 3-dimensional graphene oxide (3D GO) stalk that operates near the capillary wicking limit to achieve an evaporation flux of 34.7 kg m–2 h–1 under 1 sun conditions (1 ...kW/m2). This flux represents nearly a 100 times enhancement over a conventional solar evaporation pond. Interfacial solar evaporation traditionally uses 2D evaporators to vaporize water using sunlight, but their low evaporative water flux limits their practical applicability for desalination. Some recent studies using 3D evaporators demonstrate potential for more efficient water transfer, but the flux improvement has been marginal because of a low evaporation area index (EAI), which is defined as the ratio of the total evaporative surface area to the projected ground area. By using a 3D GO stalk with an ultrahigh EAI of 70, we achieved nearly a 20-fold enhancement over a 2D GO evaporator. The 3D GO stalk also exhibited additional advantages including omnidirectional sunlight utilization, a high evaporation flux under dark conditions from more efficient utilization of ambient heating, a dramatic increase of the evaporation rate by introducing wind, and scaling resistance in evaporating brines with a salt content of up to 17.5 wt %. This performance makes the 3D GO stalk well suited for the development of a low-cost, reduced footprint technology for zero liquid discharge in brine management applications.
Because of their innate ability to store and then release energy, long‐persistent luminescence (LPL) materials have garnered strong research interest in a wide range of multidisciplinary fields, such ...as biomedical sciences, theranostics, and photonic devices. Although many inorganic LPL systems with afterglow durations of up to hours and days have been reported, organic systems have had difficulties reaching similar timescales. In this work, a design principle based on the successes of inorganic systems to produce an organic LPL (OLPL) system through the use of a strong organic electron trap is proposed. The resulting system generates detectable afterglow for up to 7 h, significantly longer than any other reported OLPL system. The design strategy demonstrates an easy methodology to develop organic long‐persistent phosphors, opening the door to new OLPL materials.
A novel approach to achieve a pure organic long‐persistent luminescent material using a phosphonium salt doped with dimethylaniline is reported. The doped crystals can exhibit a green afterglow emission lasting up to 7 h after the cessation of UV excitation. The positive phosphonium salt holds and protects the separated charge to produce unprecedented afterglow duration.
π-Bonds connected with aromatic rings were generally believed as the standard structures for constructing highly efficient fluorophores. Materials without these typical structures, however, exhibited ...only low fluorescence quantum yields and emitted in the ultraviolet spectral region. In this work, three molecules, namely bis(2,4,5-trimethylphenyl)methane, 1,1,2,2-tetrakis(2,4,5-trimethylphenyl)ethane, and 1,1,2,2-tetraphenylethane, with nonconjugated structures and isolated phenyl rings were synthesized and their photophysical properties were systematically investigated. Interestingly, the emission spectra of these three molecules could be well extended to 600 nm with high solid-state quantum yields of up to 70%. Experimental and theoretical analyses proved that intramolecular through-space conjugation between the “isolated” phenyl rings played an important role for this abnormal phenomenon.
Long-persistent luminescence (LPL), also known as afterglow, is a phenomenon in which the material shows long-lasting luminescence after the cessation of the excitation source. The research of LPL ...continues to attract much interest due to its fundamental nature and its potential in the development of the next generation of functional materials. However, most of the current LPL materials are multicomponent inorganic systems obtained after harsh synthetic procedures and often use rare-earth metals. Recently, metal free organic long-persistent luminescence (OLPL) has gained much interest because it can bypass many of the disadvantages of inorganic systems. To date, the most successful method to generate OLPL systems is to access charge-separated states through binary donor–acceptor exciplex systems. However, it has been reported that the ratios of the binary systems affect OLPL properties, complicating the reproducibility and large-scale production of OLPL materials. Simpler OLPL systems can overcome these issues for the benefit of the development and adoption of OLPL systems. Here, we report on the rational design and synthesis of a single-component OLPL system with detectable afterglow for at least 12 min under ambient conditions. This work exemplifies an easy design principle for new OLPL materials. The investigation of the material provides valuable insights toward the generation of OLPL from a single-component system.
The development of molecular machines requires new building blocks which are easy to characterize and visualize to realize a complexity comparable to their natural counterparts such as biological ...enzymes. Furthermore, with the desire to build functional nanobots capable of navigating living organisms, it is necessary that the building blocks show mobility even in the solid state. Herein we report a system which is emissive in the amorphous state but is non‐fluorescent in the crystalline state due to the formation of extensive π‐π interactions. This dual nature could be exploited for easy visualization of its solid‐state molecular rearrangement. The emission of the amorphous film was quenched as the molecules spontaneously formed π‐π interactions even in the solid state. Scratching the non‐emissive film destroyed the interactions and restored the emission of the film. The emission quickly disappeared with an average lifetime of 20 s as the compound reformed the π‐network even at room temperature.
Beacons lit by molecular motion: Intermolecular forces drive the formation of π‐π interactions even in the solid state. Shear forces/scratching disrupt the interactions, turning on emission. The quenched π‐π‐interactions quickly reform even in a film, allowing the visualization of the molecular motions. Theoretical calculations show that the formation of π‐interactions is highly favorable and driving this motion.
The first standardized, global assessment of these fishes, using Red List criteria, reveals threatened species needing protection.
There is growing concern that in spite of the healthy status of ...several epipelagic (living near the surface) fish stocks (
1
), some scombrid (tunas, bonitos, mackerels, and Spanish mackerels) and billfish (swordfish and marlins) species are heavily overfished and that there is a lack of resolve to protect against overexploitation driven by high prices (
2
–
5
). Many populations are exploited by multinational fisheries whose regulation, from a political perspective, is exceedingly difficult. Thus, assessment and management is complicated and sometimes ineffective (
4
). Regional Fisheries Management Organizations (RFMOs) were created to manage and conserve scombrids and billfishes because of their transnational distributions and widespread economic importance (
6
). However, species-specific catch data for many scombrids and billfishes are not collected or are aggregated with other species. Even for the larger tunas, for which relatively rich data exist, population assessments and data are complex (
1
) and are difficult to combine across RFMOs, which prompts a need for alternative means of assessment.
The aggregation of molecules plays an important role in determining their function. Electron microscopy and other methods can only characterize the variation of microstructure, but are not capable of ...monitoring conformational changes. These techniques are also complicated, expensive and time-consuming. Here, we demonstrate a simple method to monitor in-situ and in real-time the conformational change of (R)-1,1'-binaphthyl-based polymers during the aggregation process using circular dichroism. Based on results from molecular dynamics simulations and experimental circular dichroism measurements, polymers with "open" binaphthyl rings are found to show stronger aggregation-annihilated circular dichroism effects, with more negative torsion angles between the two naphthalene rings. In contrast, the polymers with "locked" rings show a more restrained aggregation-annihilated circular dichroism effect, with only a slight change of torsion angle. This work provides an approach to monitor molecular aggregation in a simple, accurate, and efficient way.
UV‐B radiation is often viewed as a source of stress for higher plants. In particular, photosynthetic function has been described as a common target for UV‐B impairment; yet as our understanding of ...UV‐B photomorphogenesis increases, there are opportunities to expand the emerging paradigm of regulatory UV response. Lactuca sativa is an important dietary crop species and is often subjected to rapid sunlight exposure at field transfer. Acclimation to UV‐B and visible light conditions in L. sativa was dissected using gas exchange and chlorophyll fluorescence measurements, in addition to non‐destructive assessments of UV epidermal shielding (SUV). After UV‐B treatment, seedlings were subjected to wide‐range metabolomic analysis using liquid chromatography hybrid quadrupole time‐of‐flight high‐resolution mass spectrometry (LC‐QTOF‐HRMS). During the acclimation period, net photosynthetic rate increased in UV‐treated plants, epidermal UV shielding increased in both subsets of plants transferred to the acclimatory conditions (UV+/UV− plants) and Fᵥ/Fₘdeclined slightly in UV+/UV− plants. Metabolomic analysis revealed that a key group of secondary compounds was up‐regulated by higher light conditions, yet several of these compounds were elevated further by UV‐B radiation. In conclusion, acclimation to UV‐B radiation involves co‐protection from the effects of visible light, and responses to UV‐B radiation at a photosynthetic level may not be consistently viewed as damaging to plant development.
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