A Rapid pH-Responsive Pyraclostrobin Delivery System with Enhanced Membrane Passing Property and Fungicidal Activity against Botrytis cinerea

As the second most important fungal pathogen, Botrytis cinerea (B. cinerea) poses a serious threat to crop yields and agricultural safety. Pyraclostrobin (PYR), a broad-spectrum QoI fungicide, has been widely utilized since its launch in 2003. However, the inhibitory effects of both PYR technical and PYR formulations on B. cinerea are not outstanding. Even at a concentration of 50 μg/mL, the inhibition rates of B. cinerea by both PYR technical and PYR formulations remain below 85%. In this work, we prepared an acid-responsive Pickering emulsion encapsulating PYR (PYR@BTIB-PE), which completely inhibited B. cinerea at low concentrations (25 μg/mL) for the first time. The PYR@BTIB-PE achieved fragmentation and release within 4 min at pH 5, which was consistent with the pH around B. cinerea. The PYR@BTIB-PE can rapidly release PYR when B. cinerea infected and increased the concentration of PYR around the B. cinerea, thereby enhancing the efficacy of PYR. In addition, the released organic solvent from PYR@BTIB-PE enhanced the passing property of the B. cinerea membrane, facilitating more PYR to enter the body of B. cinerea. The improvement of the membrane passing property and rapid response release of PYR@BTIB-PE worked together to achieve complete inhibition of B. cinerea. Furthermore, the flexible and amphiphilic structures of PYR@BTIB-PE increased its interaction with the leaf surface, completely suppressed droplet splashing, and promoted droplet spreading, thereby reducing pesticide loss and improving the utilization rate of the pesticide. This study presents an efficient and rapid strategy for inhibiting B. cinerea and is also expected to be extended to other antifungal preparations.

Analyses of Experimental Dental Adhesives Based on Zirconia/Silver Phosphate Nanoparticles

This study aimed to evaluate the incorporation of zirconia/silver phosphate nanoparticles to develop experimental dental adhesives and to measure their physical and mechanical properties. The nanoparticles were synthesized by the sonication method, and the phase purity, morphological pattern, and antibacterial properties with Staphylococcus aureus and Pseudomonas aeruginosa were assessed. The silanized nanoparticles were incorporated (0, 0.15, 0.25, and 0.5 wt.%) into the photoactivated dimethacrylate resins. The degree of conversion (DC) was assessed, followed by the micro-hardness and flexural strength/modulus test. Long-term color stability was investigated. The bond strength with the dentin surface was conducted on days 1 and 30. The transmission electron microscopy and X-ray diffractogram confirmed the nano-structure and phase purity of the particles. The nanoparticles showed antibacterial activities against both strains and inhibited biofilm formation. The DC range of the experimental groups was 55-66%. The micro-hardness and flexural strength increased with the concentration of nanoparticles in the resin. The 0.5 wt.% group showed significantly high micro-hardness values, whereas a non-significant difference was observed between the experimental groups for flexural strength. The bond strength was higher on day 1 than on day 30, and a significant difference was observed between the two periods. At day 30, the 0.5 wt.% showed significantly higher values compared to other groups. Long-term color stability was observed for all the samples. The experimental adhesives showed promising results and potential to be used for clinical applications. However, further investigations such as antibacterial, penetration depth, and cytocompatibility are required.

Metal nanoparticles against fungicide resistance: alternatives or partners?

Chemical control suffers from the loss of available conventional active ingredients due to strict environmental safety regulations which, combined with the loss of fungicide efficacy due to resistance development, constitute major problems of contemporary crop protection. Metal-containing nanoparticles (MNPs) appear to have all the credentials to be next-generation, eco-compatible fungicide alternatives and a valuable anti-resistance management tool. Could the introduction of MNPs as nano-fungicides be the answer to both reducing the environmental footprint of xenobiotics and dealing with fungicide resistance? The potential of MNPs to be utilized as nano-fungicides, both as alternatives to conventional fungicides or/and as partners in combating fungicide resistance, is discussed in terms of effectiveness, potential antimicrobial mechanisms as well as synergy profiles with conventional fungicides. However, their "golden" potential to be used both as alternatives and partners of conventional fungicides to combat resistance and reduce environmental pollution is challenged by undesirable effects towards non-target organisms such as phytotoxicity, toxicity to humans and environmental ecotoxicity, constituting risks that should be considered before their commercial introduction as nano-pesticides at a large scale. © 2022 Society of Chemical Industry.

Synthesis of M-Ag3PO4, (M = Se, Ag, Ta) Nanoparticles and Their Antibacterial and Cytotoxicity Study

Silver Phosphate, Ag3PO4, being a highly capable clinical molecule, an ultrasonic method was employed to synthesize the M-Ag3PO4, (M = Se, Ag, Ta) nanoparticles which were evaluated for antibacterial and cytotoxicity activities post-characterization. Escherichia coli and Staphylococcus aureus were used for antibacterial testing and the effects of sonication on bacterial growth with sub-MIC values of M-Ag3PO4 nanoparticles were examined. The effect of M-Ag3PO4 nanoparticles on human colorectal carcinoma cells (HCT-116) and human cervical carcinoma cells (HeLa cells) was examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay and DAPI (4′,6-diamidino-2-phenylindole) staining. Additionally, we analyzed the effect of nanoparticles on normal and non-cancerous human embryonic kidney cells (HEK-293). Ag-Ag3PO4 exhibited enhanced antibacterial activity followed by Ta-Ag3PO4, Ag3PO4, and Se-Ag3PO4 nanoparticles against E. coli. Whereas the order of antibacterial activity against Staphylococcus aureus was Ag3PO4 > Ag-Ag3PO4 > Ta-Ag3PO4 > Se-Ag3PO4, respectively. Percentage inhibition of E. coli was 98.27, 74.38, 100, and 94.2%, while percentage inhibition of S. aureus was 25.53, 80.28, 99.36, and 20.22% after treatment with Ag3PO4, Se-Ag3PO4, Ag-Ag3PO4, and Ta-Ag3PO4, respectively. The MTT assay shows a significant decline in the cell viability after treating with M-Ag3PO4 nanoparticles. The IC50 values for Ag3PO4, Se-Ag3PO4, Ag-Ag3PO4, and Ta-Ag3PO4 on HCT-116 were 39.44, 28.33, 60.24, 58.34 µg/mL; whereas for HeLa cells, they were 65.25, 61.27, 75.52, 72.82 µg/mL, respectively. M-Ag3PO4 nanoparticles did not inhibit HEK-293 cells. Apoptotic assay revealed that the numbers of DAPI stained cells were significantly lower in the M-Ag3PO4-treated cells versus control.

Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease.

A pie-like structure double-sidedly assembled with ZnO-nanodisks vertically on Cu-nanoplates and its photochemical properties

A novel pie-like structure of vertically stacked ZnO-nanodisks on Cu-nanoplates interlayer is prepared for the first time by a facile synthesis. The photochemical activity of the as-prepared samples was evaluated by the degradation of Rhodamine B (RhB) under UV-light. Because of the formation of heterojunction and closely-bonded layered structure, the novel nanocomposites can restrain the recombination of charge carriers and have better collection ability of light. The photocatalytic experiments show that the composites are 258% of the catalytic activity of pure ZnO-nanodisks prepared by the same method, and the target pollutant RhB was almost completely degraded (96.5%) within only 10 mins. The novel Cu-nanoplates/ZnO-nanodisks assembled materials with greatly promoted performance are of significant interest for chemical and environmental applications.

Biological Visual Detection for Advanced Photocatalytic Oxidation toward Pesticide Detoxification

Photocatalytic oxidation treatment is an emerging and fast developed eco-friendly, energy-saving, and efficient advanced oxidation technology for degrading hazardous pesticides. The conventional chemical detection to evaluate the effects for this process depends on the broken chemical structure, only giving residual content and product chemical composition. However, it misses direct visual detection on the toxicity and the quantitative analysis of pesticide detoxification. Here, we develop a novel strategy to combine photocatalytic oxidation with a zebrafish biological model to provide a direct visual detection on the environmental detoxification. The mortality or deformity of zebrafish embryos (ZEs) acts as an indicator. Over the irradiation duration threshold, the mortality of ZEs decreases to 23.3% for pure chlorothalonil (CTL-P) after photocatalytic oxidation treatment for 1 h, and the deformity reduces to 13.3% for commercial CTL (CTL-C) after 30 min and to 3.33% for tetramethylthiuram disulfide (TMTD) after 20 min. The toxicity of CTL-C and TMTD could be completely removed by photocatalytic oxidation treatment and causes no damage to the ZE developmental morphology. Chemical analyses demonstrate the degradation of CTL into inorganic compounds and TMTD into small organic molecules. Among these highlighted heterogeneous photocatalysts (g-C₃N₄, BiVO₄, Ag₃PO₄, and P25), g-C₃N₄ exhibits the highest photocatalytic detoxification for CTL-P, CTL-C, and TMTD.

Ethanol–water ambient precipitation of {111} facets exposed Ag3PO4 tetrahedra and its hybrid with graphene oxide for outstanding photoactivity and stability

The work presents the combinative merits of {111} facet effect and the GO hybrid of Ag₃PO₄ photocatalyst with dramatically improved photocatalytic activity and admirable circulation runs for water treatment.

Biomimetic synthesis of Ag3PO4-NPs/Cu-NWs with visible-light-enhanced photocatalytic activity for degradation of the antibiotic ciprofloxacin

Cu-NWs/Ag₃PO₄-NPs can be used as photocatalysts under visible light irradiation and have high photocatalytic performance for degradation of CPFX.

Nitrogen and sulfur self-doped porous carbon from brussel sprouts as electrode materials for high stable supercapacitors

Brussel sprout-derived activated carbon materials synthesized through the activation of KOH as electrode material for electrochemical capacitor shows a good rate capability.

A high-performance dual-function material: self-assembled super long α-Fe2O3 hollow tubes with multiple heteroatom (C-, N- and S-) doping

Flow diagram of the synthesis of nitrogen doped α-Fe₂O₃ nanorods into super long hollow tubes.