Embedding AIE-type Ag28Au1 nanoclusters within ZIF-8 for improved photodynamic wound healing through bacterial eradication.

Designing antibacterial agents with rapid bacterial eradication performance is paramount for the treatment of bacteria-infected wounds. Metal nanoclusters (NCs) with aggregation-induced emission (AIE) have been considered as novel photodynamic antibacterial agents without drug resistance, but they suffer from poor photostability and low charge carrier separation efficiency. Herein, we report the design of a photodynamic antibacterial agent by encapsulating AIE-type AgAu NCs (Ag28Au1 NCs) into a zeolitic Zn(2-methylimidazole)2 framework (ZIF-8). The encapsulation of AIE-type Ag28Au1 NCs into porous ZIF-8 could not only enhance the photostability of Ag28Au1 NCs by inhibiting their aggregation but also promote the separation of photoinduced charge carriers, resulting in the rapid generation of destructive reactive oxygen species (ROS) for bacterial killing under visible-light irradiation. Consequently, the as-designed photodynamic Ag28Au1 NCs@ZIF-8 antibacterial agent could rapidly eliminate 97.7% of Escherichia coli (E. coli) and 91.6% of Staphylococcus aureus (S. aureus) within 5 min in vitro under visible light irradiation. Furthermore, in vivo experimental results have highlighted the synergistic effect created by AIE-type Ag28Au1 NCs and ZIF-8, enabling Ag28Au1 NCs@ZIF-8 to effectively eradicate bacteria in infected areas, reduce inflammation, and promote the generation of blood vessels, epithelial tissue, and collagen. This synergistic effect promoted the healing of S. aureus-infected wound, with nearly 100% of wound recovery within 11 days. This work may be interesting because it sheds light on the design of metal NC-based photodynamic nanomedicine for bacteria-infected disease treatment.

Ultrasmall copper nanoclusters as an efficient antibacterial agent for primary peritonitis therapy.

The urgent need to develop biocompatible, non-resistant antibacterial agents to effectively combat Gram-negative bacterial infections, particularly for the treatment of peritonitis, presents a significant challenge. In this study, we introduce our water-soluble Cu30 nanoclusters (NCs) as a potent and versatile antibacterial agent tailored for addressing peritonitis. The as-synthesized atomically precise Cu30 NCs demonstrate exceptional broad-spectrum antibacterial performance, and especially outstanding bactericidal activity of 100% against Gram-negative Escherichia coli (E. coli). Our in vivo experimental findings indicate that the Cu30 NCs exhibit remarkable therapeutic efficacy against primary peritonitis caused by E. coli infection. Specifically, the treatment leads to a profound reduction of drug-resistant bacteria in the peritoneal cavity of mice with peritonitis by more than 5 orders of magnitude, along with the resolution of pathological features in the peritoneum and spleen. Additionally, comprehensive in vivo biosafety assessment underscores the remarkable biocompatibility, low biotoxicity, as well as efficient hepatic and renal clearance of Cu30 NCs, emphasizing their potential for in vivo application. This investigation is poised to advance the development of novel Cu NC-based antibacterial agents for in vivo antibacterial treatment and the elimination of abdominal inflammation.

Impact of bioelectricity on DNRA process and microbial community composition within cathodic biofilms in dual-chambered bioelectrode microbial fuel cell (MFC).

The synchronous bioelectricity generation and dissimilatory nitrate reduction to ammonium (DNRA) pathway in Klebsiella variicola C1 was investigated. The presence of bioelectricity facilitated cell growth on the anodic biofilms, consequently enhancing the nitrate removal efficiency decreasing total nitrogen levels and causing a negligible accumulation of NO2- in the supernatant. Genomic analysis revealed that K. variicola C1 possessed a complete DNRA pathway and largely annotated electron shuttles. The up-regulated expression of genes narG and nirB, encoding nitrite oxidoreductase and nitrite reductase respectively, was closely associated with increased extracellular electron transfer (EET). High-throughput sequencing analysis was employed to investigate the impact of bioelectricity on microbial community composition within cathodic biofilms. Results indicated that Halomonas, Marinobacter and Prolixibacteraceae were enriched at the cathode electrodes. In conclusion, the integration of a DNRA strain with MFC facilitated the efficient removal of wastewater containing high concentrations of NO3- and enabled the environmentally friendly recovery of NH4+.

Bioelectricity facilitates carbon dioxide fixation by Alcaligenes faecalis ZS-1 in a biocathodic microbial fuel cell (MFC).

The CO2 fixation mechanism by Alcaligenes faecalis ZS-1 in a biocathode microbial fuel cell (MFC) was investigated. The closed-circuit MFC (CM) exhibited a significantly higher CO2 fixation rate (10.7%) compared to the open-circuit MFC (OC) (2.0%), indicating that bioelectricity enhances CO2 capture efficiency. During the inward extracellular electron transfer (EET) process, riboflavin concentration increased in the supernatant while cytochrome levels decreased. Genome sequencing revealed diverse metabolic pathways for CO2 fixation in strain ZS-1, with potential dominance of rTCA and C4 pathways under electrotrophic conditions as evidenced by significant upregulation of the ppc gene. Differential metabolite analysis using LC-MS demonstrated that CM promoted upregulation of various lipid metabolites. These findings collectively highlight that ZS-1 simultaneously generated electricity and fixed CO2 and that the ppc associated with bioelectricity played a critical role in CO2 capture. In conclusion, bioelectricity resulted in a significant enhancement in the efficiency of CO2 fixation and lipid production.

A Smart Pesticide-Controlled Release Platform with Dual Stimuli-Responsive Functions for Enhanced Treatment of Plant Black Shank.

Realizing controllable input of botanical pesticides is conducive to improving pesticide utilization, reducing pesticide residues, and avoiding environmental pollution but is extremely challenging. Herein, we constructed a smart pesticide-controlled release platform (namely, SCRP) for enhanced treatment of tobacco black shank based on encapsulating honokiol (HON) with mesoporous hollow structured silica nanospheres covered with pectin and chitosan oligosaccharide (COS). The SCRP has a loading capacity of 12.64% for HON and could effectively protect HON from photolysis. Owing to the pH- and pectinase-sensitive property of the pectin, the SCRP could smartly release HON in response to a low pH or a rich pectinase environment in the black shank-affected area. Consequently, the SCRP effectively inhibits the infection of P. nicotianae on tobacco with a controlled rate for tobacco black shank of up to 87.50%, which is mainly due to the SCRP's capability in accumulating ROS, changing cell membrane permeability, and affecting energy metabolism. In addition, SCRP is biocompatible, and the COS layer enables SCRP to show a significant growth-promoting effect on tobacco. These results indicate that the development of a stimuli-responsive controlled pesticide release system for plant disease control is of great potential and value for practical agriculture production.

Gold nanocluster with AIE: A novel photodynamic antibacterial and deodorant molecule.

Designing long-lasting yet high-efficiency antimicrobial and deodorant agents is an everlasting goal for environmental and public health. Here we present the design of AIE-featured Au nanoclusters (NCs) for visible-light-driven antibacterial and deodorant applications. Owing to the intriguing AIE traits, the good harvest of visible-light, and rich surface chemistry, the AIE-featured Au NCs unprecedentedly exhibit excellent visible-light-driven antibacterial activities against gram-positive (≥98.5%) and gram-negative bacteria (≥99.94%), which is resulted from their photodynamic producibility of abundant reactive oxygen species including O2•-, •OH and H2O2 via O2 reduction and subsequent H2O2 oxidation. In addition, the Au NCs are demonstrated to be biocompatible, and easy to be deployed for downstream antibacterial and deodorant applications. For example, the Au NCs-modified domestic materials (e.g., latex, ceramic glaze, organic fiber, and clothings) achieve long-lasting antibacterial efficiency of 99% and deodorant efficiency of >97.9% under visible-light irradiation. This work may shed light on designing novel AIE-featured metal NCs with photodynamic antibacterial and deodorant functions, enabling metal NCs and corresponding downstream materials to step into the photodynamic antibacterial and deodorant era.

Conjugating AIE-featured AuAg nanoclusters with highly luminescent carbon dots for improved visible-light-driven antibacterial activity.

Metal nanoclusters (NCs) have emerged as novel antibacterial agents featuring broad-spectrum antibacterial activity without drug resistance for bacteria, but suffer from fast antibacterial invalidation due to their consumption by bacteria. Herein we report the design of a visible-light-driven photodynamic antibacterial agent based on conjugating aggregation-induced emission (AIE)-featured AuAg NCs with highly luminescent carbon dots (CDs). The conjugation of CDs with AuAg NCs could not only enhance the visible-light harvest, but also promote charge carrier generation/separation via charge/energy transfer, leading to the production of abundant reactive oxygen species (ROS) for bacterial killing under visible-light irradiation. Consequently, the as-obtained CDs@AuAg NCs display excellent photodynamic antibacterial activity against both Gram-positive and Gram-negative bacteria with 4-5 orders of magnitude reduction in colony forming units, which is different from the conventional metal NC-based analogue relying on self-consumption for bacterial killing. In addition, the CDs@AuAg NCs are found to be free of cytotoxicity; the ROS capture experiments indicate that the photoproduced H2O2 by CDs@AuAg NCs is the main active species for bacterial killing, accounting for nearly 48% of the total antibacterial efficacy. This study provides a paradigm for the design of metal NC-based photodynamic antibacterial agents for diverse bactericidal applications.

Bismuth oxychloride nanostructure coated carbon sponge as flow-through electrode for highly efficient rocking-chair capacitive deionization.

Rocking-chair capacitive deionization (RCDI), as the next generation technique of capacitive deionization, has thrived to be one of the most promising strategies in the desalination community, yet was hindered mostly by its relatively low desalination rate and stability. Motivated by the goal of simultaneously enhancing the desalination rate and structural stability of the electrode, this paper reports an anion-driven flow-through RCDI (AFT-RCDI) system equipped with BiOCl nanostructure coated carbon sponge (CS@BiOCl for short; its backbone is derived from commercially available melamine foam with minimum capital cost) as the flow-through electrode. Owning to the rational design of the composite electrode material with minimum charge transfer resistance and ultrahigh structure stability as well as the superior flow-through cell architecture, the AFT-RCDI displays excellent desalination performance (desalination capacity up to 107.33 mg g-1; desalination rate up to 0.53 mg g-1s-1) with superior long-term stability (91.75% desalination capacity remained after 30 cycles). This work provides a new thought of coupling anion capturing electrode with flow-through cell architecture and employing a low-cost CS@BiOCl electrode with commercially available backbone material, which could shed light on the further development of low-cost electrochemical desalination systems.

Layered double hydroxide coated electrospun carbon nanofibers as the chloride capturing electrode for ultrafast electrochemical deionization.

Slow desalination kinetics and poor durability of the electrodes are two key limitations of electrochemical deionization (EDI) that are considered to be the next generation of capacitive desalination (CDI). Herein, we report the design of a high-efficiency chloride removal electrode material for accelerating the desalination kinetics and concurrently improving the durability of EDI, which is based on coating NiMn-Cl layered double hydroxides (LDHs) on the surface of electrospun carbon nanofibers (CNFs@LDHs). The salient features of the as-developed CNFs@LDHs are that applying layer-structured LDHs with abundant redox-active sites to accelerate the pseudo-capacitive ion storage via fast ion intercalation/deintercalation, and leveraging the rigid CNF backbone to strengthen its durability by preventing the potential aggregation of LDHs. As expected, the CNFs@LDH based EDI system displays an ultrafast desalination rate of 0.51 mg g-1 s-1 and outstanding long-term stability (only 10.66 % desalination capacity reduction after 35 cycles), which is achieved without sacrificing its excellent desalination capacity (72.04 mg g-1). This work could be inspirational for the future design of ultrafast yet durable EDI approaching industrial desalination applications.

Marrying luminescent Au nanoclusters to TiO2 for visible-light-driven antibacterial application.

Long-lasting yet visible-light-driven bacterial inhibition is highly desired for environmental protection and public health maintenance. However, conventional semiconductors such as titanium dioxide (TiO2) are impotent for such antibacterial application due to their low utilization rate for visible light. Herein we report the design of a long-lasting yet visible-light-driven antibacterial agent based on marrying luminescent Au nanoclusters (Au NCs for short) to TiO2 (TiO2-NH2@Au NCs). The as-obtained TiO2-NH2@Au NC antibacterial agent not only possesses superior utilization for visible light due to the participation of Au NCs as a good photosensitizer, but also has excellent separation efficacy of photogenerated carriers, thereby efficiently enhancing the generation of reactive oxygen species (ROS) for killing bacteria. Consequently, the TiO2-NH2@Au NCs display excellent antibacterial activity with good durability against both Gram-positive and Gram-negative bacteria such as Staphylococcus aureus (99.37%) and Escherichia coli (99.92%) under visible-light irradiation (λ ≥ 400 nm). This study is interesting because it provides a paradigm change in the design of long-lasting yet visible-light-driven NC-based antibacterial agents for diversified bactericidal applications.

Controllable synthesis of hierarchical MoS2 nanotubes with ultra-uniform and superior storage potassium properties.

Molybdenum disulfide (MoS2) is a promising nanomaterial which has been extensively investigated in photo-/electro-catalysis, sensors, and batteries due to its excellent physical/chemical properties. In this manuscript, MoS2 hierarchical nanotubes with hollow nanostructure are successfully synthesized via a facile hydrothermal method. SEM indicates that such MoS2 nanotubes have perfect uniformity while TEM demonstrates the hollow structure. Specifically, the ratio of MoS2 to the randomly produced polysulfide in the synthesized MoS2 nanotubes is 4.29 which confirms that the synthesized MoS2 nanotubes have quite high quality. Compared with the previous studies, our MoS2 nanotubes show superior rate capability and cyclability (127 mAh g-1 at 200 mA g-1 after 100 cycles) in the potassium ion battery.

Water-soluble metal nanoclusters: recent advances in molecular-level exploration and biomedical applications.

Water-soluble metal nanoclusters (MNCs) have received extraordinary attention in both fundamental and applied fields due to their ultrasmall size, unique molecular-like properties, rich surface chemistry, benign biocompatibility, and good stability. Currently, the state-of-the-art research on water-soluble MNCs has been upgraded from the nanoscale to the molecular level especially in the following aspects: (1) synthesis of highly luminescent MNCs featuring aggregation-induced emission (AIE), (2) Engineering the ligand shell of MNCs for controllable surface chemistry and (3) Tracking the reductive growth process of MNCs. Such molecular-level research progress of water-soluble MNCs in turn facilitated their development in biomedical applications. In this Frontier Article, we start our discussion by briefly summarizing the recent molecular-level research progress of water-soluble MNCs in the above-mentioned three aspects, followed by our perspectives on these fundamental aspects. Afterwards, the latest advance in biomedical applications of water-soluble MNCs is discussed. We hope that this Frontier Article could stimulate more studies on the molecular- or atomic-level understanding and biomedical applications of water-soluble MNCs.

Cyclodextrin-functionalized Ag/AgCl foam with enhanced photocatalytic performance for water purification.

The application of visible light-induced photocatalysts for photocatalytic pollution mitigation has become a promising strategy due to the inexhaustible solar energy. And how to improve pollutants degradation rate is still a meaningful work. Many researchers dealt with this issue by enhancing visible light absorption of photocatalysts. However, few studies focus on this issue by improving semiconductor's absorption property of organic pollutants. Hence, in this work, we prepared the Ag/AgCl foam coated per-6-thio-ß-cyclodextrin (SH-ß-CD) to improve the photocatalytic activity of Ag/AgCl foam. Here, we chose SH-ß-CD because it has a special cavity that can effectively absorb and capture proper organic pollutants via host-guest interaction, which makes it an ideal pollutants surface adsorber when coated on the surface of Ag/AgCl particles. Hence, those trapped pollutants in the cavities can be attacked directly by those reactive oxidation species (ROS) that produced by Ag/AgCl particles under visible light irradiation, resulting in the significant promotion of pollution mitigation rate. The experimental results demonstrated the photodegradation rate constant of methyl orange (MO) by Ag/AgCl@ß-CD foam (k = 0.120 min-1) increased approximately 2.6 times compared with pure Ag/AgCl from (k = 0.048 min-1). We anticipate our SH-ß-CD modified Ag/AgCl foam would be a promising candidate for photodegradation of organic pollutants in wastewater remediation.

Fabrication of Photocontrolled Surfaces for Oil/Water Separation through Sulfur(VI) Fluoride Exchange.

Smart surfaces with controllable wettability have attracted substantial interest owing to the potential use of these materials for the separation of oil from oily water caused by frequent oil-spill accidents. Because there are few separation materials on the market that are capable of switching between hydrophobicity and hydrophilicity, this work reports an efficient and low-cost method to fabricate a photoresponsive membrane through the sulfur(VI) fluoride exchange reaction (SuFEx) between poly(4-vinylphenol sulfofluoridate) and (E)-1-(4-(tert-butoxy)phenyl)-2-(4-(trifluoromethoxy)phenyl)diazene. The resulting material displays switchable wettability between hydrophobic and hydrophilic states when subjected to ultraviolet or visible irradiation. This membrane can be recycled (greater than five times) and features superior efficiency (up to 97.9 %) for the separation of oils that have both higher and lower densities than water. This work is the first proof-of-concept application of SuFEx to fabricate functional materials for environmental remediation.

Micro-Nanocomposites in Environmental Management.

Water pollution, a worldwide issue for the human society, has raised global concerns on environmental sustainability, calling for high-performance materials for effective treatments. Since the traditional techniques have inherent limitations in treatment speed and efficiency, nanotechnology is subsequently used as an environmental technology to remove pollutants through a rapid adsorption and degradation process. Therefore, here, various adsorbent and photodegradation composite materials leading to effective water remediation are summarized and predicted. Notably, recent advances in simultaneous adsorption and photodegradation micro-nanocomposites are outlined. Such materials can not only completely adsorb and remove contaminants, but the micro-nanocomposites can also be directly reused without further treatment. Finally, the future development of this unique system is discussed.

A Robust and Cost-Effective Superhydrophobic Graphene Foam for Efficient Oil and Organic Solvent Recovery.

Water pollution caused by chemical reagent leaking, industrial wastewater discharging, and crude oil spills has raised global concerns on environmental sustainability, calling for high-performance absorbent materials for effective treatments. However, low-cost materials capable of effectively separating oils and organic solvents from water with a high adsorption capacity and good recyclability are rare on the market. Here, a cost-effective method is reported to fabricate high-performance graphene modified absorbents through the facile thermal reduction of graphene oxide on the skeletons of melamine foam. By integrating the high porosity, superior elasticity, and mechanical stability of raw sponge with the chemical stability and hydrophobicity of graphene sheets, the as-fabricated graphene foam not only possesses a rough and superhydrophobic surface, but also exhibits an excellent adsorption performance and extraordinary recyclability for various oils and organic solvents. It is worth mentioning that the superhydrophobic surface also endows the graphene foam with an excellent efficiency for oil/water separation. More importantly, the cost-effective fabrication method without involving expensive raw materials and sophisticated equipment permits a scale-up of the graphene foam for pollution disposal. All these features make the graphene foam an ideal candidate for removal and collection of oils and organic solvents from water.