Yunsong Zhang

For agricultural films, spectral matching, UV protection, and environmental durability are essential for efficient crop production. A self-cleaning silane-crosslinked red/blue dual-emission carbon dot/polyvinyl alcohol composite film (KH/RB-CQDs/PVA) was fabricated via a covalent anchoring strategy. RB-CQDs were synthesized by a two-step hydrothermal method using o-phenylenediamine: initial blue-emitting carbon cores formed, then phosphoric acid-assisted secondary treatment covalently bridged residual precursor-derived red fluorophores onto cores through pyrophosphate bonds, as evidenced by TEM, XPS, ³¹P NMR, HPLC-MS and DFT. This rigid bridging suppressed excessive core growth and energy transfer while spatially separating dual emission, endowing excellent photostability (>95% fluorescence retention after 50 min UV and 30 d storage). Subsequently, KH-560 was employed to construct a robust covalent crosslinked network anchoring RB-CQDs in PVA and forming rough Si-O-Si surface structures, confirmed by SEM and XPS. The resulting film exhibited 16.16% quantum yield, 291% tensile strength enhancement, 95% UV shielding, and <1% contaminant residue. Chlorophyll fluorescence kinetics, gas-exchange analyses, and photosynthetic response curves demonstrated that KH/RB-CQDs/PVA increased the potato net photosynthetic rate by 55.46% and tuber yield by 76% through synergistic optimization of photosystem II electron transport and RuBisCO-mediated carbon assimilation. This work provides a molecular design principle for high-performance intelligent agricultural films.

Cryptotanshinone (CPT), the main active compound of Salvia miltiorrhiza, is known for its anti-inflammatory, antioxidative, and antifibrotic effects. In this study, the hepatoprotective effect and mechanisms of CPT were explored using transcriptome and network pharmacology. A carbon tetrachloride-induced acute liver injury (ALI) mouse model was established. The anti-ALI effects of different doses of CPT were evaluated by analysis of biochemical indicators, histopathological staining, and immunohistochemical analysis. Combining network pharmacology with transcriptomic analysis revealed therapeutic targets, which were subsequently validated through polymerase chain reaction and Western blotting. CPT (40 mg/kg) treatment significantly reduced the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, tumor necrosis factor-α, interleukin-6, and interleukin-1β in model mice and regulated oxidative stress indicators, including malonaldehyde, superoxide dismutase, glutathione, and catalase. MCP-1 protein expression in the liver was inhibited by treatment with CPT. Network pharmacology revealed 72 core targets involved in the treatment of ALI by CPT. By combining transcriptomic data from liver tissue, three key targets—TNF-α, TLR9, and ADORA2B—were identified, along with the TLR, IL-17, and TNF signaling pathways. Furthermore, PCR and Western blot assays revealed that CPT significantly decreased TNF-α, TLR9, and ADORA2B expression levels in the livers of ALI mice. In conclusion, the hepatoprotective effects of CPT may be related to the suppression of TNF-α-, TLR9-, and ADORA2B-mediated inflammation, oxidative stress, and apoptosis. These results provide a foundation for the development of CPT as a potential therapeutic agent for ALI.

Heteroatom‐doped single‐atom nanozymes (SAEs) hold great promise as enzyme mimics, yet their catalytic mechanisms remain unclear. This study reveals that the proton driving mechanism induced by sulfur doping in single‐atom FeN ₂ O ₂ carbon dots (S‐FeCDs) significantly enhances peroxidase (POD)‐like activity. Synthesized via low‐temperature carbonization, S‐FeCDs exhibit FeN ₂ O ₂ coordination with sulfur in the second shell, as confirmed by XAFS and AC‐STEM. The POD‐specific activity of S‐FeCDs reached 295 U mg ⁻¹ , which is 11.2‐fold higher than that of sulfur‐free FeCDs, with natural enzyme‐like kinetics. In situ experiments, kinetic and mechanistic studies revealed that sulfur doping promotes H ₂ O dissociation, enhances H ⁺ adsorption, reduces the Δ G for H ₂ O ₂ ‐to‐·OH conversion. DFT revealed a lowered energy barrier for the rate‐determining step (2*OH → *O + *H ₂ O) from 2.50 to 1.62 eV. In vivo, S‐FeCDs demonstrated broad pH efficacy in MRSA‐infected wound models, achieving near‐complete healing within 7 days. The proton driving mechanism was further validated through nitro compound reduction, demonstrating accelerated N─H bond activation. This work highlights the critical role of sulfur‐induced proton dynamics in enhancing SAEs performance, providing a rational strategy for designing multifunctional nanozymes in biomedical and catalytic applications.

Heteroatom‐doped single‐atom nanozymes (SAEs) hold great promise as enzyme mimics, yet their catalytic mechanisms remain unclear. This study reveals that the proton driving mechanism induced by sulfur doping in single‐atom FeN ₂ O ₂ carbon dots (S‐FeCDs) significantly enhances peroxidase (POD)‐like activity. Synthesized via low‐temperature carbonization, S‐FeCDs exhibit FeN ₂ O ₂ coordination with sulfur in the second shell, as confirmed by XAFS and AC‐STEM. The POD‐specific activity of S‐FeCDs reached 295 U mg ⁻¹ , which is 11.2‐fold higher than that of sulfur‐free FeCDs, with natural enzyme‐like kinetics. In situ experiments, kinetic and mechanistic studies revealed that sulfur doping promotes H ₂ O dissociation, enhances H ⁺ adsorption, reduces the Δ G for H ₂ O ₂ ‐to‐·OH conversion. DFT revealed a lowered energy barrier for the rate‐determining step (2*OH → *O + *H ₂ O) from 2.50 to 1.62 eV. In vivo, S‐FeCDs demonstrated broad pH efficacy in MRSA‐infected wound models, achieving near‐complete healing within 7 days. The proton driving mechanism was further validated through nitro compound reduction, demonstrating accelerated N─H bond activation. This work highlights the critical role of sulfur‐induced proton dynamics in enhancing SAEs performance, providing a rational strategy for designing multifunctional nanozymes in biomedical and catalytic applications.

The development of composite photocatalysts with high charge transfer efficiency, great visible light absorption, and quick recovery has aroused the interest of many researchers. Herein, based on the hydrothermal assisted vacuum freeze drying method, CdS, Fe₃O₄, and N-TiO₂ were, respectively, fixed in the inner, middle, and outer layers of nitrogen-doped graphene aerogel for preparation of the site-specific magnetic porous Z-scheme CdS/Fe₃O₄@N-doped graphene aerogel microtube/N-doped TiO₂ (CdS/Fe₃O₄@NGAM/N-TiO₂) photocatalyst. For the composite, Fe₃O₄@NGAM carrier with porous and tubular structure not only helps the recycle and reactants/productions mass transport in the photocatalytic process but also ensures the well-steered transfer of electrons and holes from CdS and N-TiO₂ in the Z-type heterojunction system, greatly improving the separation of photogenerated carriers. Besides, Fe₃O₄ can also work as a Fenton catalyst to activate hydrogen peroxide which is generated in situ by CdS. Thus, the CdS/Fe₃O₄@NGAM/N-TiO₂ composite presents excellent degradation efficiencies towards methyl orange ((MO) 98% removal rate within 50 min), bisphenol A ((BPA) 96% removal rate within 50 min), tetracycline hydrochloride ((TCH) 96% removal rate within 120 min) and strong stabilities after 6 cycles. The free radical removal experiments show that ·O₂⁻ and ·OH are the main active substances of catalysis, which further confirms the synergistic effect of photocatalysis and Fenton catalysis.