Silver Nanoparticle-Embedded Carbon Nitride: Antifungal Activity on Candida albicans and Toxicity toward Animal Cells.

The development of engineered nanomaterials has been considered a promising strategy to control oral infections. In this study, silver-embedded carbon nitrides (Ag@g-CN) were synthesized and tested against Candida albicans, investigating their antifungal action and biocompatibility in animal cells. Ag@g-CN was synthesized by a simple one-pot thermal polymerization technique and characterized by various analytical techniques. X-ray diffraction (XRD) analysis revealed slight alterations in the crystal structure of g-CN upon the incorporation of Ag. Fourier transform infrared (FT-IR) spectroscopy confirmed the presence of Ag-N bonds, indicating successful silver incorporation and potential interactions with g-CN's amino groups. UV-vis spectroscopy demonstrated a red shift in the absorption edge of Ag@g-CN compared with g-CN, attributed to the surface plasmon resonance effect of silver nanoparticles. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed the 2D layered sheet like morphology of both materials. The Ag 3d peaks found in X-ray photoelectron spectroscopy (XPS) confirmed the presence of metallic Ag0 nanoparticles in Ag@g-CN. The Ag@g-CN materials exhibited high antifungal activity against reference and oral clinical strains of C. albicans, with minimal inhibitory concentration (MIC) ranges between 16-256 µg/mL. The mechanism of Ag@g-CN on C. albicans was attributed to the disruption of the membrane integrity and disturbance of the biofilm. In addition, the Ag@g-CN material showed good biocompatibility in the fibroblastic cell line and in Galleria mellonella, with no apparent cytotoxicity observed at a concentration up to 1000 µg/mL. These findings demonstrate the potential of the Ag@g-CN material as an effective and safe antifungal agent for the treatment of oral fungal infections.

Purine-Doped g-C3N4-Modified Fabrics for Personal Protective Masks with Rapid and Sustained Antibacterial Activity.

Protective masks are critical to impeding microorganism transmission but can propagate infection via pathogen buildup and face touching. To reduce this liability, we integrated electrospun photocatalytic graphitic carbon nitride (g-C3N4) nanoflakes into standard surgical masks to confer a self-sanitization capacity. By optimizing the purine/melamine precursor ratio during synthesis, we reduced the g-C3N4 band gap from 2.92 to 2.05 eV, eliciting a 4× increase in sterilizing hydrogen peroxide production under visible light. This narrower band gap enables robust photocatalytic generation of reactive oxygen species from environmental and breath humidity to swiftly eliminate accumulated microbes. Under ambient sunlight, the g-C3N4 nanocomposite mask layer achieved a 97% reduction in the bacterial viability during typical use. Because the optimized band gap also allows photocatalytic activity under shadowless lamp illumination, the self-cleaning functionality could mitigate infection risk from residual pathogens in routine hospital settings. Both g-C3N4 and polycaprolactone demonstrate favorable biocompatibility and biodegradability, making this approach preferable over current commercially available metal-based options. Given the abundance and low cost of these components, this scalable approach could expand global access to reusable self-sanitizing protective masks, serving as a sustainable public health preparedness measure against future pandemics, especially in resource-limited settings.

Graphitic carbon nitride alleviates cadmium toxicity to microbial communities in soybean rhizosphere.

Cadmium (Cd) contamination has led to various harmful impacts on soil microbial ecosystem, agricultural crops, and thus human health. Nanomaterials are promising candidates for reducing the accumulation of heavy metals in plants. In this study, graphitic carbon nitride (g-C3N4), a two-dimensional polymeric nanomaterial, was applied for ameliorating Cd phytotoxicity to soybean (Glycine max (L.) Merr.). Its impacts on rhizosphere variables, microorganisms, and metabolism were examined. It was found that g-C3N4 increased carbon/nitrogen/phosphorus (C/N/P) content, especially when N contents were averagely 4.2 times higher in the g-C3N4-treated groups. g-C3N4 significantly induced alterations in microbial community structures (P < 0.05). The abundance of the probiotics class Nitrososphaeria was enriched (on average 70% higher in the g-C3N4-treated groups) as was Actinobacteria (226% higher in the g-C3N4 group than in the CK group). At the genus level, g-C3N4 recruited more Bradyrhizobium (122% higher) in the Cd + g-C3N4 group than in the Cd group and more Sphingomonas (on average 24% higher) in the g-C3N4-treated groups. The changes of microbial clusters demonstrated the potential of g-C3N4 to shape microbial functions, promote plant growth, and enhance Cd resistance, despite observing less pronounced modifications in microbial communities in Cd-contaminated soil compared to Cd-free soil. Moreover, abundance of functional genes related to C/N/P transformation was more significantly promoted by g-C3N4 in Cd-contaminated soil (increased by 146%) than in Cd-free one (increased by 32.8%). Therefore, g-C3N4 facilitated enhanced microbial survival and adaptation through the amplification of functional genes. These results validated the alleviation of g-C3N4 on the microbial communities in the soybean rhizosphere and shed a new light on the application of environmental-friendly nanomaterials for secure production of the crop under soil Cd exposure.

Could nitrogen compounds be indicators of tolerance to high doses of Cu and Fe in the cultivation of Leucaena leucocephala?

Nitrogen metabolism and the production of primary and secondary metabolites vary according to biotic and abiotic factors such as trace elements (TE) stress, and can, therefore, be considered biomarkers. The present study evaluated the effect of copper (Cu) and iron (Fe) TE, separately, on the metabolism of nitrogen compounds and biomass production, partitioned into shoot and roots of Leucaena leucocephala (Lam.) de Wit., and identified possible defense mechanisms linked to nitrogen metabolism. At 120 days of cultivation, the biomass production of L. leucocephala was higher when exposed to excess Fe than Cu. Nonetheless, the biomass gain (%) of plants exposed to Cu was higher, especially the biomass gains in roots. The tolerance and biomass production of L. leucocephala is related to the regulation of nitrogen metabolism and production of secondary metabolites. The biochemistry of plant metabolism against the excess of Cu and Fe TE manifested similarly, but with some specifics regarding the chemical nature of each metal. There was a reduction in the content of ureides and proteins and an increase in amino acids in the roots in relation to the increase in Cu and Fe concentrations. There was low accumulation of proline in the roots in treatments 400 and 500 mg/dm3 compared to the control for both TE. On the other hand, the total phenolic compounds in the roots increased. Our results indicate that the increased synthesis of amino acids and the accumulation of phenolic compounds is involved in the tolerance of L. leucocephala to Cu and Fe.

Synthesis of lathyrane diterpenoid nitrogen-containing heterocyclic derivatives and evaluation of their anti-inflammatory activities.

As our ongoing work on lathyrane diterpenoid derivatization, three series of lathyrane diterpenoid derivatives were designed and synthesized based combination principles, including pyrazole, thiazole and furoxan moieties. Biological evaluation indicated that compound 23d exhibited excellently inhibitory activity on LPS-induced NO production in RAW264.7 cells (IC50 = 0.38 ± 0.18 µM). The preliminary structure-activity relationships (SARs) suggested that phenylsulfonyl substituted furoxan moiety had the strongest ability to improve anti-inflammatory activity of lathyrane diterpenoids. Furthermore, compound 23d significantly reduced the level of ROS. Its molecular mechanism was related to inhibiting the transcriptional activation of Nrf2/HO-1 pathway. Based on these considerations, 23d might be a promising anti-inflammatory agent, which is noteworthy for further exploration.

ß-Cyclodextrin-Derivative-Functionalized Graphene Oxide/Graphitic Carbon Nitride Composites with a Synergistic Effect for Rapid and Efficient Sterilization.

The nonselectivity of phototherapy and the hydrophobicity of phototherapy agents limit their application in the treatment of antibiotic-resistant bacteria. In this work, ß-cyclodextrin-derivative-functionalized graphene oxide (GO)/graphitic carbon nitride (g-C3N4) antibacterial materials (CDM/GO/CN) were designed and synthesized. CN is used as a photosensitizer for photodynamic therapy (PDT) and GO as a photothermal agent for photothermal therapy (PTT). In addition, the supramolecular host-guest complex on the substrate can not only increase the inherent water solubility of the substrate and reduce the aggregation of the photosensitizer/photothermal agent but also manipulate the interaction between the photosensitizer/photothermal agent and bacteria to capture specific bacteria. The hyperthermia caused by PTT denatures proteins on the cell membrane, allowing reactive oxygen species (ROS) to enter the cell better and kill bacteria. The specific capture of Escherichia coli CICC 20091 by mannose significantly improves the sterilization efficiency and reduces side effects. The synergistic antibacterial agent shows excellent antibacterial efficacy of over 99.25% against E. coli CICC 20091 after 10 min of 635 + 808 nm dual-light irradiation. Moreover, cell proliferation experiments show that the composite material has good biocompatibility, expected to have applications in bacterial infections.

Phosphorus-nitrogen compounds: part 53-synthesis, characterization, cytotoxic and antimicrobial activity, DNA interaction and molecular docking studies of new mono- and dispirocyclotriphosphazenes with pendant arm(s).

Mono-/dispirocyclotriphosphazenes with pendant arm(s) are robust, but they are less investigated inorganic ring systems. In this study, a series of mono (3 and 4)- and dispirocyclotriphosphazenes with 4-chloro-benzyl pendant arm(s) (13-16) was obtained from the Cl exchange reactions of hexachlorocyclotriphosphazene with sodium (N-benzyl)aminopropanoxides (1 and 2). When compound (3) reacted with excess pyrrolidine, morpholine, tetra-1,4-dioxa-8-azaspiro[4,5]decane (DASD) and piperidine, the fully substituted monospirocyclotriphosphazenes (7, 9, 10 and 12) occurred. But, the reactions of 4 with excess piperidine and morpholine produced the gem-piperidino (5)- and morpholino (6)-substituted monospirocyclotriphosphazenes, whereas the reactions of 4 with excess pyrrolidine and DASD gave the fully substituted monospirocyclotriphosphazenes (8) and (11). However, it should be indicated that these derivatives were obtained to be used for the investigation of their spectral, stereogenic and biological properties. The structures of 5, 7 and 14 were determined crystallographically. X-ray data of 5 and 14 displayed that both of compounds were chiral in solid state, and their absolute configurations were assigned as R and RR. Additionally, the antimicrobial activities of phosphazenes were investigated. Minimum inhibitory concentrations, minimal bacterial concentrations and minimum fungicidal concentrations of phosphazenes were determined. The interactions of phosphazenes with plasmid DNA were evaluated by agarose gel electrophoresis. The cytotoxic activities of compounds were studied against L929 fibroblast and DLD-1 colon cancer cells. In addition, density functional theory calculations of 5, 7 and 14 were reported, and their molecular docking studies with DNA, E. coli DNA gyrase and topoisomerase IV were presented.

PVA based nanofiber containing cellulose modified with graphitic carbon nitride/nettles/trachyspermum accelerates wound healing.

Today, bacterial cellulose has received a great deal of attention for its medical applications due to its unique structural properties such as high porosity, good fluid uptake, good strength, and biocompatibility. This study aimed to fabricate and study bacterial cellulose/graphitic carbon nitride/nettles/trachyspermum nanocomposite by immersion and PVA/BC/g-C3 N4 /nettles/trachyspermum nanofiber by electrospinning method as a wound dressing. The g-C3 N4 and g-C3 N4 solution were synthesized and then were characterized using Fourier transform infrared, X-ray diffraction, Zeta Potential, and scanning electronic microscope analyzes. Also, the antibacterial properties of the synthesized materials were proved by gram-positive and gram-negative bacteria using the minimum inhibitory concentration method. Besides, the toxicity, migration, and cell proliferation results of the synthesized materials on NIH 3T3 fibroblasts were evaluated using MTT and scratch assays and showed that the BC/PVA/g-C3 N4 /nettles/trachyspermum composite not only had no toxic effect on cells but also contributed to cell survival, cell migration, and proliferation has done. To evaluate the mechanical properties, a tensile strength test was performed on PVA/BC/g-C3 N4 /nettles/trachyspermum nanofibers, and the results showed good strength of the nanocomposite. In addition, in vivo assay, the produced nanofibers were used to evaluate wound healing, and the results showed that these nanofibers were able to accelerate the wound healing process so that after 14 days, the wound healing percentage showed 95%. Therefore, this study shows that PVA/BC/g-C3 N4 /nettles/trachyspermum nanofibers effectively inhibit bacterial growth and accelerate wound healing.

Enhanced antimicrobial activity of konjac glucomannan nanocomposite films for food packaging.

This paper aims at providing a new strategy for developing konjac glucomannan-based antibacterial films with excellent performances. Here, novel nanocomposite films based on photodynamic and photothermal synergism strategy were developed by incorporating graphite carbon nitride nanosheets/MoS2 nanodots (CNMo) into konjac glucomannan (KGM) matrix. Scanning electron microscope, transmission electron microscope, high resolution transmission, high angle annular dark field and element mapping confirmed the successful fabrication of CNMo. The steady and dynamic rheological behavior as well as the good stability of film-forming solution showed that the intermolecular hydrogen bonding was formed. The influences of CNMo content on the structural, mechanical and thermal properties as well as hydrophobicity of KGM films were investigated. This film has a broad-spectrum antibacterial activity. It could prolong the shelf life of cherry tomatoes. Moreover, hemolysis and cells experiment confirm that this film is safe. This strategy is expected to broaden the application of antibacterial packaging.

Design, synthesis and antibacterial evaluation of ocotillol derivatives with polycyclic nitrogen-containing groups.

Aim: With the increasing abuse of antibacterial drugs, multidrug-resistant bacteria have become a burden on human health and the healthcare system. To find alternative compounds effective against hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA), novel derivatives of ocotillol were synthesized. Methods & Results: Ocotillol derivatives with polycyclic nitrogen-containing groups were synthesized and evaluated for in vitro antibacterial activity. Compounds 36-39 exhibited potent antibacterial activity against HA-MRSA, with MIC = 8-64 µg/ml. Additionally, a combination of compound 37 and the commercially available antibiotic kanamycin showed synergistic inhibitory effects, with a fractional inhibitory concentration index of ≤0.375. Conclusion: Compound 37 has a strong inhibitory effect, and this derivative has potential for use as a pharmacological tool to explore antibacterial mechanisms.

Copper iodide decorated graphitic carbon nitride sheets with enhanced visible-light response for photocatalytic organic pollutant removal and antibacterial activities.

The photocatalytic process is an environmentally-friendly procedure that has been well known in the destruction of organic pollutants in water. The multiple semiconductor heterojunctions are broadly applied to enhance the photocatalytic performances in comparison to the single semiconductor. Polymeric semiconductors have received much attention as inspiring candidates owing to their adjustable optical absorption features and simply adaptable electronic structure. The shortcomings of the current photocatalytic system, which restricts their technical applications incorporate fast charge recombination, low-utilization of visible radiation, and low immigration capability of the photo-induced electron-hole. This paper indicates the novel fabrication of new CuI/g-C3N4 nanocomposite by hydrothermal and ultrasound-assisted co-precipitation methods. The structure, shape, and purity of the products were affected by different weight percentages and fabrication processes. Electron microscope unveils that CuI nanoparticles are distributed on g-C3N4. The bandgap of pure carbon nitride is estimated at 2.70 eV, and the bandgap of the nanocomposite has increased to 2.8 eV via expanding the amount of CuI. The CuI/C3N4 nanocomposite has a great potential to degrade cationic and anionic dyes in high value because of its appropriate bandgap. It can be a great catalyst for water purification. The photocatalytic efficiency is affected by multiple factors such as types of dyes, fabrication methods, the light sources, mass ratios, and scavengers. The fabricated CuI/C3N4 nanocomposite exposes higher photocatalytic performance than the pure C3N4 and CuI. The photocatalytic efficiency of nanocomposite is enhanced by enhancing the amount of CuI. Besides, the fabricated CuI/C3N4 revealed remarkable reusability without the obvious loss of photocatalytic activity. The antibacterial activity of the specimens reveals that the highest antimicrobial activities are revealed against P. aeruginosa and E. coli. These results prove that the nanocomposite possesses high potential for killing bacteria, and it can be nominated as a suitable agent against bacteria.

Proton-Functionalized Graphitic Carbon Nitride for Efficient Metal-Free Destruction of Escherichia coli under Low-Power Light Irradiation.

Universal access to clean water has been a global ambition over the years. Photocatalytic water disinfection through advanced oxidation processes has been regarded as one of the promising methods for breaking down microbials. The forefront of this research focuses on the application of metal-free photocatalysts for disinfection to prevent secondary pollution. Graphitic carbon nitride (g-C3 N4 ) has achieved instant attention as a metal-free and visible-light-responsive photocatalyst for various energy and environmental applications. However, the photocatalytic efficiency of g-C3 N4 is still affected by its rapid charge recombination and sluggish electron-transfer kinetics. In this contribution, two-dimensionally protonated g-C3 N4 was employed as metal-free photocatalyst for water treatment and demonstrated 100 % of Escherichia coli within 4 h under irradiation with a 23 W light bulb. The introduction of protonation can modulate the surface charge of g-C3 N4 ; this enhances its conductivity and provides a "highway" for the delocalization of electrons. This work highlights the potential of conjugated polymers in antibacterial application.

Expression of Genes Encoding Manganese Peroxidase and Laccase of Ganoderma boninense in Response to Nitrogen Sources, Hydrogen Peroxide and Phytohormones.

Ganoderma produces lignolytic enzymes that can degrade the lignin component of plant cell walls, causing basal stem rot to oil palms. Nitrogen sources may affect plant tolerance to root pathogens while hydrogen peroxide (H2O2), salicylic acid (SA) and jasmonic acid (JA) play important roles in plant defense against pathogens. In this study, we examined the expression of genes encoding manganese peroxidase (MnP) and laccase (Lac) in Ganoderma boninense treated with different nitrogen sources (ammonium nitrate, ammonium sulphate, sodium nitrate and potassium nitrate), JA, SA and H2O2. Transcripts encoding MnP and Lac were cloned from G. boninense. Of the three GbMnP genes, GbMnP_U6011 was up-regulated by all nitrogen sources examined and H2O2 but was down-regulated by JA. The expression of GbMnP_U87 was only up-regulated by JA while GbMnP_35959 was up-regulated by ammonium nitrate but suppressed by sodium nitrate and down-regulated by H2O2. Among the three GbLac genes examined, GbLac_U90667 was up-regulated by ammonium nitrate, JA, SA and H2O2; GbLac_U36023 was up-regulated by JA and H2O2 while GbLac_U30636 was up-regulated by SA but suppressed by ammonium sulphate, sodium nitrate, JA and H2O2. Differential expression of these genes may be required by their different functional roles in G. boninense.

Sulfur and nitrogen-containing compounds from the whole bodies of Blaps japanensis.

Pipajiains H-J (1-3), three new phenolic derivatives with an unusual sulfone group, pipajiamides A-C (4-6), three new amide derivatives, pipajiaine A (7), one new imidazole analogue, and pipajiaine B (8), a pair of new pyrrolidine derivatives, along with three known compounds were isolated from the insect Blaps japanensis. Their structures were identified by spectroscopic and computational methods. Chiral HPLC was used to separate the (-)- and (+)-antipodes of 4 and 8. Biological activities of all the new compounds against extracellular matrix in rat renal proximal tubular cells, human cancer cells (A549, Huh-7, and K562), COX-2, ROCK1, and JAK3 were evaluated. The results show that compounds 2, (+)-4, and (-)-4 are active against kidney fibrosis, whereas, compound 9 is active toward human cancer cells, inflammation, and JAK3 kinase.

Current Trends in the Application of Nanomaterials for the Removal of Emerging Micropollutants and Pathogens from Water.

Water resources contamination has a worldwide impact and is a cause of global concern. The need for provision of clean water is becoming more and more demanding. Nanotechnology may support effective strategies for the treatment, use and reuse of water and the development of next-generation water supply systems. The excellent properties and effectiveness of nanomaterials make them particularly suitable for water/wastewater treatment. This review provides a comprehensive overview of the main categories of nanomaterials used in catalytic processes (carbon nanotubes/graphitic carbon nitride (CNT/g-C3N4) composites/graphene-based composites, metal oxides and composites, metal-organic framework and commercially available nanomaterials). These materials have found application in the removal of different categories of pollutants, including pharmaceutically active compounds, personal care products, organic micropollutants, as well as for the disinfection of bacterial, viral and protozoa microbial targets, in water and wastewater matrices. Apart from reviewing the characteristics and efficacy of the aforementioned nanoengineered materials for the removal of different pollutants, we have also recorded performance limitations issues (e.g., toxicity, operating conditions and reuse) for their practical application in water and wastewater treatment on large scale. Research efforts and continuous production are expected to support the development of eco-friendly, economic and efficient nanomaterials for real life applications in the near future.

Facile fabrication of silver iodide/graphitic carbon nitride nanocomposites by notable photo-catalytic performance through sunlight and antimicrobial activity.

Silver iodide/graphitic carbon nitride nanocomposites have been successfully fabricated through sonication-assisted deposition-precipitation route at room temperature and hydrothermal method. Varied mass ratios and preparation processes can modify the structure, purity, shape, and scale of specimens. The purity of the product was confirmed by Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray crystallography. The morphology and size of specimens could be observed with transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). The bandgap was evaluated around 2.82 eV for pure g-C3N4. The bandgap has reduced to 2.70 eV by increasing the quantity of silver iodide in the nanocomposites. The photocatalytic activity of AgI/C3N4 has been studied over the destruction of rhodamine B (RhB) and methyl orange (MO) through visible radiation due to their suitable bandgap. The as-prepared AgI/C3N4 nanocomposites photocatalyst revealed better photocatalytic behavior than the genuine AgI and C3N4 which ascribed to synergic impacts at the interconnection of C3N4 and AgI. Furthermore, these nanocomposites have great potential for being a great antibacterial agent.

Sulfur-doped g-C3N4 nanosheets for photocatalysis: Z-scheme water splitting and decreased biofouling.

In this study, an S-doped g-C3N4 nanosheet was prepared as a photocatalyst for effective oxygen evolution reaction. Sulfur plays a crucial role in S-doped g-C3N4 not only in increasing the charge density but also in reducing the energy band gap of S-doped g-C3N4 via substitution of nitrogen sites. S-doped g-C3N4 can serve as an oxygen-evolved photocatalyst, when combined with Ru/SrTiO3:Rh in the presence of [Co(bpy)3]3+/2+ as an electron mediator, enables photocatalytic overall water splitting under visible light irradiation with hydrogen and oxygen production rates of 24.6 and 14.5 µmol-h-1, respectively. Moreover, the photocatalytic overall water splitting to produce H2 and O2 using this Z-scheme system could use for five runs to at least 94.5 h under visible light irradiation. On the other hand, S-doped g-C3N4 can reduce biofouling by bacteria such as Escherichia coli by more than 70%, by simply incubating the S-doped g-C3N4 sample with bacterial solution under light irradiation. Our results suggest that S-doped g-C3N4 is a potentially effective, green, and promising material for a variety of photocatalytic applications.

Photocatalytically Active Graphitic Carbon Nitride as an Effective and Safe 2D Material for In Vitro and In Vivo Photodynamic Therapy.

Thanks to its photocatalytic property, graphitic carbon nitride (g-C3 N4 ) is a promising candidate in various applications including nanomedicine. However, studies focusing on the suitability of g-C3 N4 for cancer therapy are very limited and possible underlying molecular mechanisms are unknown. Here, it is demonstrated that photoexcitation of g-C3 N4 can be used effectively in photodynamic therapy, without using any other carrier or additional photosensitizer. Upon light exposure, g-C3 N4 treatment kills cancer cells, without the need of any other nanosystem or chemotherapeutic drug. The material is efficiently taken up by tumor cells in vitro. The transcriptome and proteome of g-C3 N4 and light treated cells show activation in pathways related to both oxidative stress, cell death, and apoptosis which strongly suggests that only when combined with light exposure, g-C3 N4 is able to kill cancer cells. Systemic administration of the mesoporous form results in elimination from urinary bladder without any systemic toxicity. Administration of the material significantly decreases tumor volume when combined with local light treatment. This study paves the way for the future use of not only g-C3 N4 but also other 2D nanomaterials in cancer therapy.

Construction of heterostructured g-C3N4/ZnO/cellulose and its antibacterial activity: experimental and theoretical investigations.

A g-C3N4/ZnO/cellulose ternary composite (labeled as CNZCel) with an ordered structure and excellent antibacterial properties has been successfully synthesized via a facile method. Its morphology, microstructure and components have been analyzed by using XRD, SEM, TEM and EDS, and the results corroborate the co-existence of three components in the ternary composite. It is revealed that ZnO particles are connected to the layered g-C3N4 and simultaneously attached to the cellulose substrate. This microstructural feature is also borne out by the relativistic density functional study of a finite g-C3N4-ZnO-cellulose cluster. Both experimental and theoretical results unravel that the interfacial bonding interactions in the ternary composite improve electron transfer among components and enable high-efficiency spatial separation of photogenerated electrons and holes. Consequently, good antibacterial performance of the composite has been found in tests. This study provides the prospect of preparing low-cost and environment-friendly food packaging materials, which are also endowed with excellent antibacterial activity.

Bioactive Nitrogenous Secondary Metabolites from the Marine Sponge Genus Haliclona.

Marine sponge genus Haliclona, one of the most prolific sources of natural products, contains over 600 species but only a small part of them had been classified and chemically investigated. On the basis of extensive literature search, this review firstly summarizes 112 nitrogenous secondary metabolites from classified and unclassified Haliclona sponges as well as from their symbiotic microorganisms. Most of these substances have only been found in Haliclona sponges, and display diverse bioactive properties with potential applications in new drug discovery.