Aggregation Effect on Multiperformance Improvement in Aryl-Armed Phenazine-Based Emitters.

The concept of aggregate science was proposed to explain changes in materials performance that accompany the generation of aggregates, but aggregation-triggered multifunction improvements in a class of materials have rarely been reported. Herein, we present the first report of a new class of multifunctional aggregation-induced emission (AIE) luminogens (AIEgens) based on 5,10-diarylphenazine (DPZ) derivates with full-wavelength emission. Intriguingly, multiple properties, such as fluorescence intensity and free radical and type I reactive oxygen species (ROS) efficiencies, could be simultaneously activated from the unimolecular level to the aggregate state. The mechanisms of this multiple performance improvement are discussed in detail based on sufficient performance characterization, and some of the newly prepared AIEgens exhibited toxicity to cancer cells during photodynamic therapy. This work systematically demonstrates the positive effect of aggregation on improving multiple functions of materials, which is expected to promote the development of aggregate science theory for the design of multifunctional materials.

Oxygen-Embedded Pentacene Based Near-Infrared Chemiluminescent Nanoprobe for Highly Selective and Sensitive Visualization of Peroxynitrite In Vivo.

Peroxynitrite (ONOO-) is involved in neurodegenerative, inflammatory, cardiovascular disorders, cancers, and other pathological progress. However, current imaging methods for sensing ONOO- usually suffer from high background/autofluorescence for fluorescent probes and poor selectivity/short emission wavelength for chemiluminescent probes. Herein, we present a novel chemiluminescent molecule (oxygen-embedded quinoidal pentacene) responsive to ONOO- for the first time, on the basis of which we rationally construct a near-infrared nanoprobe for detecting ONOO- via chemiluminescence resonance energy transfer (CRET) mechanism. Notably, our nanoprobe exhibits good selectivity, ultrahigh sensitivity (nanomole level), low background noise, fast response, and high water solubility. Moreover, the near-infrared emission from CRET offers higher tissue penetration of the chemiluminescent signal. Finally, our nanoprobe is further successfully applied to detecting endogenous ONOO- in mice with abdominal inflammation, drug-induced hepatotoxicity, or tumor models in vivo. In summary, the self-luminescing nanoprobes can act as an alternative visualizable tool for illuminating the mechanism of ONOO- involved in the specific pathological process.

Oxygen-Embedded Quinoidal Acene Based Semiconducting Chromophore Nanoprobe for Amplified Photoacoustic Imaging and Photothermal Therapy.

Photoacoustic (PA) imaging as a noninvasive biomedical imaging technology exhibits high spatial resolution and deep tissue penetration for in vivo imaging. In order to fully explore the potential of PA imaging in biomedical applications, new contrast agents with improved PA stability and efficiency are in high demand. Herein, we present a new PA agent based on an oxygen-embedded quinoidal nonacene chromophore that is self-assembled into nanoparticles (Nano(O-Nonacene)-PEG), assisted by polyethylene glycol (PEG). Notably, the photothermal conversion efficiency of Nano(O-Nonacene)-PEG is 1.5 fold that of semiconducting polymer nanoparticles (Nano(PCPDTBT)-PEG) and 2.8 fold that of Au nanorods, owing to the low quantum yield of Nano(O-Nonacene)-PEG. Thereby, Nano(O-Nonacene)-PEG possess a greatly elevated PA signal intensity, compared to Nano(PCPDTBT)-PEG and Au nanorods, which have been widely explored for PA imaging. Due to the high resistance to photo bleaching, Nano(O-Nonacene)-PEG exhibits higher PA signal stability, which may be employed for long-term PA imaging. Moreover, when magnetic Zn0.4Fe2.6O4 nanoparticles are incorporated into Nano(O-Nonacene)-PEG, not only are magnetic resonance signals generated but also the photoacoustic efficacy is greatly enhanced. Therefore, Nano(O-Nonacene)-PEG offers distinct properties: (i) the elevated photoacoustic effect allows for high-resolution photoacoustic imaging, (ii) small size (10 nm in diameter) results in efficient tumor-targeting, and (iii) the facile application of efficient photothermal therapy in vivo. The current work offers the possibility of oxygen-embedded quinoidal acene as a promising PA probe for precision phototheranostics.

Selective Visualization of the Endogenous Peroxynitrite in an Inflamed Mouse Model by a Mitochondria-Targetable Two-Photon Ratiometric Fluorescent Probe.

Peroxynitrite (ONOO-) is a kind of reactive oxygen species (ROS) with super activity of oxidization and nitration, and overproduction of ONOO- is associated with pathogenesis of many diseases. Thus, accurate detection of ONOO- with high sensitivity and selectivity is imperative for elucidating its functions in health or disease states. Herein we for the first time present a new two-photon ratiometric fluorescent ONOO- probe (MITO-CC) based on FRET mechanism by combining rational design strategy and dye-screening approach. MITO-CC, with fast response rate (within 20 s), excellent sensitivity (detection limit = 11.30 nM) and outstanding selectivity toward ONOO-, was successfully applied to ratiometric detection of endogenous ONOO- produced by HepG2/RAW264.7 cells and further employed for imaging oxidative stress in an inflamed mouse model. Therefore, probe MITO-CC could be a potential biological tool to explore the roles of ONOO- under different physiological and pathological settings.

A highly efficient polyampholyte hydrogel sorbent based fixed-bed process for heavy metal removal in actual industrial effluent.

High sorption capacity, high sorption rate, and fast separation and regeneration for qualified sorbents used in removing heavy metals from wastewater are urgently needed. In this study, a polyampholyte hydrogel was well designed and prepared via a simple radical polymerization procedure. Due to the remarkable mechanical strength, the three-dimensional polyampholyte hydrogel could be fast separated, easily regenerated and highly reused. The sorption capacities were as high as 216.1 mg/g for Pb(II) and 153.8 mg/g for Cd(II) owing to the existence of the large number of active groups. The adsorption could be conducted in a wide pH range of 3-6 and the equilibrium fast reached in 30 min due to its excellent water penetration for highly accessible to metal ions. The fixed-bed column sorption results indicated that the polyampholyte hydrogel was particularly effective in removing Pb(II) and Cd(II) from actual industrial effluent to meet the regulatory requirements. The treatment volumes of actual smelting effluent using one fixed bed column were as high as 684 bed volumes (BV) (7736 mL) for Pb(II) and 200 BV (2262 mL) for Cd(II). Furthermore, the treatment volumes of actual smelting effluent using tandem three columns reached 924 BV (31,351 mL) for Pb(II) and 250 BV (8483 mL) for Cd(II), producing only 4 BV (136 mL) eluent. Compared with the traditional high density slurry (HDS) process with large amount of sludge, the proposed process would be expected to produce only a small amount of sludge. When the treatment volume was controlled below 209.3 BV (7103 mL), all metal ions in the actual industrial effluent could be effectively removed (<0.01 mg/L). This wok develops a highly practical process based on polyampholyte hydrogel sorbents for the removal of heavy metal ions from practical wastewater.