Uptake, translocation and metabolism of imidacloprid loaded within fluorescent mesoporous silica nanoparticles in tomato (Solanum lycopersicum)

Visual tracking of engineered nanomaterials-facilitated pesticide absorption and translocation in plants

Visualizing the movement of pesticides carried by engineered nanoparticles within plants is vital for understanding their behavior. This research presents a novel visualization technique for intuitively monitoring the manner of nanocarriers delivering pesticides to plants. Using in situ surface-enhanced Raman spectroscopy (SERS) imaging analysis, the performance of engineered nanomaterials (ENMs) as carriers to enhance the transdermal transport of pesticides on plant leaves was successfully evaluated. The hydrophilic nature of polyvinylpyrrolidone (PVP) was observed to facilitate the stable adsorption of ENMs such as gold nanoparticles (Au NPs) on the hydrophilic molecules or functional groups on the leaf surface. Additionally, the gold-sulfur bond between Au NPs and dimethoate enhanced the adhesion and absorption of the pesticide by the plant. Notably, the small-sized Au NPs-dimethoate complex exhibited greater penetration depth and velocity compared to its larger counterpart. The uneven distribution of the Au NPs-dimethoate complex across the leaf cross-section was influenced by the physical structure. Overall, the penetrating capacity of Au NPs on plant leaves played a crucial role in enhancing the effective delivery of dimethoate, increasing both the adsorption capacity and penetration rate. This advancement results in a reduction in the quantity of pesticide applied, fundamentally mitigating the environmental pollution and aligning with environmental conservation objectives.

Carbon dots based cascading nanozymes mitigate phytotoxicity in lettuces under imidacloprid stress

Improper pesticide use induces oxidative stress and disrupts detoxification systems in plants. We synthesized CDs with cascading nanozyme activities to mitigate phytotoxicity in lettuces under imidacloprid (IMI) stress. CDs exhibit superoxide dismutase-like (SOD-like) and peroxidase-like (POD-like) activities. Surface modifications and analysis of CDs, the SOD-like activity relies on the -NH2, -COOH, and -OH groups for binding superoxide anions (O2•-), while POD-like activity depends on -COOH and CO groups, also, CO group provides π-system and the electron-deficient structure for electron transfer. Practically, under IMI stress, CDs strengthen multiple defense systems in lettuces, reducing levels of reactive oxygen toxicity (O2•-, H2O2, and MDA, by 26.77 %, 48.52 %, and 13.10 %, respectively). Meanwhile, CDs upregulate detoxification gene expression, resulting in a 42.74 % reduction in IMI residue in lettuces. Moreover, the acceptable daily intake of IMI in lettuces treated with CDs was less than 18.0 % of the reference dose, even at high-concentration IMI.

Nanocarrier foliar uptake pathways affect delivery of active agents and plant physiological response

Layered double hydroxide (LDH) nanoparticles enable foliar delivery of genetic material, herbicides, and nutrients to promote plant growth and yield. Understanding the foliar uptake route of nanoparticles is needed to maximize their effectiveness and avoid unwanted negative effects. In this study, we investigated how delivering layered double hydroxide (d = 37 ± 1.5 nm) through the adaxial (upper) or abaxial (lower) side of leaves affects particle uptake, nutrient delivery, and photosynthesis in tomato plants. LDH applied on the adaxial side was embedded in the cuticle and accumulated at the anticlinal pegs between epidermal cells. On the abaxial side, LDH particles penetrated the cuticle less, but the presence of the stomata enables penetration to deeper leaf layers. Accordingly, the average penetration levels of LDH relative to the cuticle were 2.47 ± 0.07, 1.25 ± 0.13, and 0.75 ± 0.1 μm for adaxial, abaxial with stomata, and abaxial without stomata leaf segments, respectively. In addition, the colocalization of LDH with the cuticle was ∼2.3 times lower for the adaxial application, indicating the ability to penetrate the cuticle. Despite the low adaxial stomata density, LDH-mediated delivery of magnesium (Mg) from leaves to roots was 46% higher for the adaxial than abaxial application. In addition, adaxial application leads to ∼24% higher leaf CO2 assimilation rate and higher biomass accumulation. The lower efficiency from the abaxial side was, at least partially, a result of interference with the stomata functionality which reduced stomatal conductance and evapotranspiration by 28% and 25%, respectively, limiting plant photosynthesis. This study elucidates how foliar delivery pathways through different sides of the leaves affect their ability to deliver active agents into plants and consequently affect the plants' physiological response. That knowledge enables a more efficient use of nanocarriers for agricultural applications.

Real-Time In Situ Tracking of the Penetration and Uptake Behavior of Nano-pesticides in Tea Plants Using Surface-Enhanced Raman Spectroscopy

In situ monitoring of the uptake and transportation process of nano-pesticides during crop growth remains challenging thus far. In this report, the different three sizes of surface-enhanced Raman spectroscopy probes of nano-pesticides loaded with ferbam and acetamiprid are representative non-systemic or systemic pesticides, respectively. The probes were verified to have strong signals of the Raman spectrum enhancement effect. They were further applied on the leaves and roots of tea plants. Within 5 h, the nano-pesticides of 50 nm and 100 nm except 150 nm probes could rapidly penetrate young tea leaves to a depth of about 150-290 μm. Whereas none of the probes were observed to penetrate mature leaves and roots of tea plants. The result showed that the penetration rate depended on the size of the nano-pesticides and the structure or maturity of the plant tissue rather than the loaded pesticides. The penetration rate of small-sized nano-pesticides in young tea leaves is the fastest.

Enantioselective effects of chiral profenofos on the conformation for human serum albumin

Profenofos, as a typical chiral organophosphorus pesticide, can cause various environmental problems and even endanger human health when used in excess. The toxicity of chiral profenofos was investigated through multispectral analysis, molecular docking, and density functional theory (DFT), employing human serum albumin (HSA) as the model protein. Fluorescence titration and lifetime measurements demonstrated that the interaction between chiral profenofos and HSA involves static quenching. Chiral profenofos forms a 1:1 complex with HSA at site II (subdomain IIIA), primarily driven by hydrophobic interactions and hydrogen bonds. Notably, the binding efficacy diminishes as temperature increases. Spectroscopic analyses confirm that chiral profenofos alters the microenvironment and structure of HSA, with the R-enantiomer exerting a greater impact than the S-enantiomer. Consequently, the toxicological implications of the R-profenofos is significantly more pronounced. Investigating the molecular-level toxic effects of chiral pesticides enhances the thoroughness of pesticide assessments, aids in understanding their distribution, metabolism, and associated risks, and facilitates the development of mitigation strategies.

Thiacloprid-silica nano-delivery system enhances toxicity against Aphis gossypii and improves non-target biosafety

Nanotechnology aligns with the requirements of sustainable development of agriculture, and nano-pesticides offer a promising approach to controlling agricultural pests and increasing productivity. Non-target predators also play a crucial role in pest controls and enhancing the efficacy of pesticide on target organisms. Reducing the toxicity of pesticides to non-target organisms is key to of coordinating chemical control and biological control methods. Therefore, it is essential to assess the toxicity of nano-pesticides on non-target predators. In this study, a carbon dots-doped mesoporous silica nano-delivery system (Thi@CD-MSN) was successfully developed using CD-MSN as carrier material and thiacloprid (Thi) as a model pesticide. The results demonstrated that the synthesized Thi@CD-MSN exhibited a relatively high loading efficiency (33.58%). Laboratory bioassay experiments revealed that Thi@CD-MSN demonstrated effective insecticidal activity (LC50 = 21.67 mg/L) in controlling Aphis gossypii Glover. Besides, the acute toxicity of Thi@CD-MSN on Chrysoperla pallens larvae was significantly lower than that of Thi, as was its toxicity to 4T1 cells. These findings suggest that CD-MSN can serve as an ecological safety carrier for pesticide delivery, improving the effective utilization of Thi while reducing the risks to non-target predators. These results are essential for comprehending the effects of nano-pesticides on non-target predators, providing informative data for implementing biological and chemical control strategies. It strengthens the safety evaluation of nano-pesticides.

Pectin-Coated Iron-Based Metal-Organic Framework Nanoparticles for Enhanced Foliar Adhesion and Targeted Delivery of Fungicides

Conventional agrochemicals are underutilized due to their large particle sizes, poor foliar retention rates, and difficult translocation in plants, and the development of functional nanodelivery carriers with high adhesion to the plant body surface and efficient uptake and translocation in plants remains challenging. In this study, a nanodelivery system based on a pectin-encapsulated iron-based MOF (TF@Fe-MOF-PT NPs) was constructed to enhance the utilization of thifluzamide (TF) in rice plants by taking advantage of the pectin affinity for plant cell walls. The prepared TF@Fe-MOF-PT NPs exhibited an average particle size of 126.55 nm, a loading capacity of 27.41%, and excellent dual-stimulus responses to reactive oxygen species and pectinase. Foliar washing experiments showed that the TF@Fe-MOF-PT NPs were efficiently adhered to the surfaces of rice leaves and stems. Confocal laser scanning microscopy showed that fluorescently labeled TF@Fe-MOF-PT NPs were bidirectionally delivered through vascular bundles in rice plants. The in vitro bactericidal activity of the TF@Fe-MOF-PT NPs showed better inhibitory activity than that of a TF suspension (TF SC), with an EC50 of 0.021 mg/L. A greenhouse test showed that the TF@Fe-MOF-PT NPs were more effective than TF SC at 7 and 14 d, with control effects of 85.88 and 78.59%, respectively. It also reduced the inhibition of seed stem length and root length by TF SC and promoted seedling growth. These results demonstrated that TF@Fe-MOF-PT NPs can be used as a pesticide nanodelivery system for efficient delivery and intelligent release in plants and applied for sustainable control of pests and diseases.

Bidirectional Uptake, Transfer, and Transport of Dextran-Based Nanoparticles in Plants for Multidimensional Enhancement of Pesticide Utilization

The development of effective multifunctional nano-delivery approaches for pesticide absorption remains a challenge. Here, a dextran-based pesticide delivery system (MBD) is constructed to deliver tebuconazole for multidimensionally enhancing its effective utilization on tomato plants. Spherical MBD nanoparticles are obtained through two-step esterification of dextran, followed by tebuconazole loading using the Michael addition reaction. Confocal laser scanning microscopy shows that fluorescein isothiocyanate-labeled MBD nanoparticles can be bidirectionally transported in tomato plants and a modified quick, easy, cheap, effective, rugged, and safe-HPLC approach demonstrates the capacity to carry tebuconazole to plant tissues after 24 h of root uptake and foliar spray, respectively. Additionally, MBD nanoparticles could increase the retention of tebuconazole on tomato leaves by up to nearly 2.1 times compared with the tebuconazole technical material by measuring the tebuconazole content retained on the leaves. In vitro antifungal and pot experiments show that MBD nanoparticles improve the inhibitory effect of tebuconazole against botrytis cinerea by 58.4% and the protection against tomato gray molds by 74.9% compared with commercial suspensions. Furthermore, the MBD nanoparticles do not affect the healthy growth of tomato plants. These results underline the potential for the delivery system to provide a strategy for multidimensional enhancement of pesticide efficacy.

Enantioselective effects of chiral prothioconazole and its metabolites: Oxidative stress in HepG2 cells and lysozyme activity

Chiral pesticides may exhibit enantioselectivity in terms of bioconcentration, environmental fate, and reproductive toxicity. Here, chiral prothioconazole and its metabolites were selected to thoroughly investigate their enantioselective toxicity and mechanisms at the molecular and cellular levels. Multispectral techniques revealed that the interaction between chiral PTC/PTCD and lysozyme resulted in the formation of a complex, leading to a change in the conformation of lysozyme. Meanwhile, the effect of different conformations of PTC/PTCD on the conformation of lysozyme differed, and its metabolites were able to exert a greater effect on lysozyme compared to prothioconazole. Moreover, the S-configuration of PTCD interacted most strongly with lysozyme. This conclusion was further verified by DFT calculations and molecular docking as well. Furthermore, the oxidative stress indicators within HepG2 cells were also affected by chiral prothioconazole and its metabolites. Specifically, S-PTCD induced more substantial perturbation of the normal oxidative stress processes in HepG2 cells, and the magnitude of the perturbation varied significantly among different configurations (P > 0.05). Overall, chiral prothioconazole and its metabolites exhibit enantioselective effects on lysozyme conformation and oxidative stress processes in HepG2 cells. This work provides a scientific basis for a more comprehensive risk assessment of the environmental behaviors and effects caused by chiral pesticides, as well as for the screening of highly efficient and less biotoxic enantiomeric monomers.

Assessing the effectiveness of imidacloprid and thiamethoxam via root irrigation against Megalurothrips usitatus (Thysanoptera: Thripidae) and its residual effects on cowpea

Systemic neonicotinoid insecticides (NEOs) applied by seed-treatment or root application have emerged as a prevalent strategy for early-season insect pest management. This research investigated the effectiveness of imidacloprid and thiamethoxam, administered through root irrigation, in managing thrips in cowpea [Vigna unguiculata (Linn.) Walp.], and the residual properties of both insecticides in cowpea and soil. The results show that thrips density depends on the application rate of insecticides. At the maximum application rate (1,500 µg/ml, active ingredient), imidacloprid and thiamethoxam controlled thrips densities below the economic injury level (EIL, the EIL of thrips on cowpea was 7/flower) for 20 days and 25 days with the density of 6.90 and 6.93/flower at the end of the periods, respectively. Imidacloprid and thiamethoxam residues decreased gradually over time and decreased sharply after 15 days after treatment (DAT), the 2 insecticides were not detected (<0.001 mg/kg) at 45 DAT. According to our findings, the application of imidacloprid and thiamethoxam via root irrigation proved residual control lasting up to 20-25 days for controlling thrips damage at experimental rates, with a strong association to their residual presence in cowpea (0.6223 < R2 < 0.9545). Considering the persistence of the imidacloprid and thiamethoxam, the maximum tested application rate (1,500 µg/ml) was recommended. As the residues of imidacloprid and thiamethoxam were undetectable in cowpea pods at all tested rates, it may be suggested that the use of each insecticide is safe for consumers and effective against thrips, and could be considered for integrated thrips management in the cowpea ecosystem.

A reversible CHEF-based NIR fluorescent probe for sensing Hg2+ and its multiple application in environmental media and biological systems

Hg²⁺ poses a great threat to human health and the environment due to its bioaccumulation and permanent damage. Herein, a reversible CHEF-based near-infrared fluorescent probe 2-(3-((E)-4-((E)-4-(diethylamino)-2- hydroxybenzylidene)amino)styryl)-5,5-dimethylcyclohex-2-en-1-ylidene)propanedinitrile (DHEY) capable of specifically recognizing Hg²⁺ was constructed. DHEY exhibits advantages of large Stokes shift (157 nm), excellent selectivity, high sensitivity (LOD = 3.2 μg/L), and fast response efficiency (<3 min). Interestingly, DHEY can also realize rapid and effective detection of Hg²⁺ after being recycled 7 times. The successful recovery of trace Hg²⁺ in different environmental water samples fully demonstrates the potential of DHEY for actual applications. In particular, DHEY enables real-time observation of the distribution and translocation pattern of exogenous Hg²⁺ in HeLa cells and zebrafish. This work provides important theoretical support for investigating the fate of heavy metal ions in the environment using fluorescence techniques.

Enantioselective effect of chiral prothioconazole on the conformation of bovine serum albumin

As a typical chiral triazole fungicide, the enantioselective toxicity of prothioconazole to environmental organisms is of increasing concern. Herein, the binding mechanism of chiral PTCs to BSA was investigated by multi-spectral technique and molecular docking. Fluorescence titration and fluorescence lifetime experiments fully established that quenching BSA fluorescence by chiral PTCs is static quenching and could spontaneously bind to BSA. Hydrophobic interactions dominate the binding process of chiral PTCs to BSA. Differently, although both chiral PTCs and BSA have a primary binding site, the difference in chiral isomerism leads to a stronger binding ability of S-PTC than R-PTC. Both configurations of PTC can change the conformation of BSA and induce changes in the microenvironment around its amino acid residues, and the effect of S-PTC is more significant. Overall, S-PTC exhibited a more substantial effect on BSA structure relative to R-PTC. That is, S-PTC may lead to more potent potential toxicological effects on environmental organisms. This study provides a comprehensive assessment of the environmental behavior of chiral pesticides and their potential toxicity to environmental organisms at the molecular level and provides a theoretical basis for the screening of highly effective and biologically less toxic enantiomers of chiral pesticides.

Bioactivity, Uptake, and Distribution of Prothioconazole Loaded on Fluorescent Double-Hollow Shelled Mesoporous Silica in Soybean Plants

Prothioconazole (PTC) has been widely utilized for plant fungal disease control, but its metabolite prothioconazole-desthio (PTC-d) exhibits reproductive toxicity. In the present study, carbon quantum dot (CQD)-modified fluorescent double-hollow shelled mesoporous silica nanoparticles (FL-MSNs) loaded with PTC, referred to as PTC@FL-MSNs, were constructed with an average size of 369 nm and a loading capacity of 28.1 wt %, which could increase the antifungal efficiency of PTC. In addition, upright fluorescence microscope and UPLC-MS/MS studies showed that PTC@FL-MSNs could be effectively transported via root uptake and foliar spray in soybean plants. Compared to a 30% PTC dispersible oil suspension agent, the PTC@FL-MSN treatment group showed higher concentrations (leaves: 0.50 > 0.48 mg/kg), longer half-lives for degradation (leaves: 3.62 > 3.21 d; roots: 3.39 > 2.82 d), and fewer metabolites. These findings suggest that sustained pesticide release and toxicity reduction are potential applications for PTC nanofungicide delivery technology.

Peripheral neuropathy, protein aggregation and serotonergic neurotransmission: Distinctive bio-interactions of thiacloprid and thiamethoxam in the nematode Caenorhabditis elegans

Due to worldwide production, sales and application, neonicotinoids dominate the global use of insecticides. While, neonicotinoids are considered as pinpoint neurotoxicants that impair cholinergic neurotransmission in pest insects, the sublethal effects on nontarget organisms and other neurotransmitters remain poorly understood. Thus, we investigated long-term neurological outcomes in the decomposer nematode Caenorhabditis elegans. In the adult roundworm the neonicotinoid thiacloprid impaired serotonergic and dopaminergic neuromuscular behaviors, while respective exposures to thiamethoxam showed no effects. Thiacloprid caused a concentration-dependent delay of the transition between swimming and crawling locomotion that is controlled by dopaminergic and serotonergic neurotransmission. Age-resolved analyses revealed that impairment of locomotion occurred in young as well as middle-aged worms. Treatment with exogenous serotonin rescued thiacloprid-induced swimming deficits in young worms, whereas additional exposure with silica nanoparticles enhanced the reduction of swimming behavior. Delay of forward locomotion was partly caused by a new paralysis pattern that identified thiacloprid as an agent promoting a specific rigidity of posterior body wall muscle cells and peripheral neuropathy in the nematode (lowest-observed-effect-level 10 ng/ml). On the molecular level exposure with thiacloprid accelerated protein aggregation in body wall muscle cells of polyglutamine disease reporter worms indicating proteotoxic stress. The results from the soil nematode Caenorhabditis elegans show that assessment of neurotoxicity by neonicotinoids requires acknowledgment and deeper research into dopaminergic and serotonergic neurochemistry of nontarget organisms. Likewise, it has to be considered more that different neonicotinoids may promote diverse neural end points.

Effects of plant morphology, vitamin C, and other co-present pesticides on the deposition, dissipation, and metabolism of chlorothalonil in pakchoi

Pesticide residues have been a focus of attention of food safety. Different varietal pakchoi plants grown in open fields were studied to understand effects of morphology, leaf wax content, and vitamin C on the deposition, dissipation, and metabolism of chlorothalonil. The loose pakchoi plants and flat leaves were conducive to pesticide deposition, but not plants with erect leaves. Chlorothalonil on nine varieties of pakchoi dissipated in the first-order kinetic with T1/2 s of 1.4 ~ 2.0 days. Vitamin C in pakchoi could promote the dissipation of chlorothalonil. Carbendazim could significantly promote the dissipation of chlorothalonil on pakchoi. Interestingly, four metabolites of chlorothalonil were identified in the pakchoi and the metabolic pathway was predicted by DFT calculations. The risk assessment showed that pakchoi were safe for consumption after 10 days of application of the recommended dose. This work provides important information for the understanding of deposition, dissipation, and metabolism of chlorothalonil in pakchoi.

Construction of a novel fluorescent nanocarrier with double hollow shells for pH-controlled release of imidacloprid and its distribution and transport in bok choy

Nanotechnology has been widely used in the field of pesticides. Integration of nano-pesticides and carbon dot fluorescence can fully utilize the potential for high admission of pesticides on leaves and convenience observation of its distribution and transport in the tissues. In the present study, a fluorescent mesoporous nanosilica with double hollow shells for loading imidacloprid (Im@FL-MSNs) was designed and synthesized. The physical and chemical properties of the imidacloprid nanocarriers were characterized by transmission electron microscopy (TEM), FT-IR spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and N₂ adsorption/desorption. When the mass ratio of FL MSNs to imidacloprid is 6:5, Im@FL-MSNs exhibits good fluorescence properties, high loading efficiency (∼30%), great slow-release performance as well as pH controllability. Besides, Im@FL-MSNs can improve the ability of imidacloprid to adhere on the leaf surface of bok choy (Initial contact angled is greater than 80°）. Importantly, Im@FL-MSNs did not reduce the biological activity of imidacloprid (LC₅₀ (95% CI) = 1.43 mg/L). It was able to visually study the absorption and distribution of imidacloprid in bok choy plants, and provide theoretical and technical guidance for pesticide reduction.

Aptamer-Gated Mesoporous Silica Nanoparticles for N Protein Triggered Release of Remdesivir and Treatment of Novel Coronavirus (2019-nCoV)

Since the 2019-nCoV outbreak was first reported, hundreds of millions of people all over the world have been infected. There is no doubt that improving the cure rate of 2019-nCoV is one of the most effective means to deal with the current serious epidemic. At present, Remdesivir (RDV) has been clinically proven to be effective in the treatment of SARS-CoV-2. However, the uncertain side effects make it important to reduce the use of drugs while ensuring the self-healing effect. We report an approach here with targeted therapy for the treatment of SARS-CoV-2 and other coronaviruses illness. In this study, mesoporous silica was used as the carrier of RDV, the nucleocapsid protein (N protein) aptamer was hybridized with the complementary chain, and the double-stranded DNA was combined with gold nanoparticles as the gates of mesoporous silica pores. When the RDV-loaded mesoporous silica is incubated with the N protein, aptamer with gold nanoparticles dissociate from the complementary DNA oligonucleotide on the mesoporous silica surface and bind to the N protein. The releasing of RDV was determined by detecting the UV-vis absorption peak of RDV in the solution. These results show that the RDV delivery system designed in this work has potential clinical application for the treatment of 2019-nCoV.

A Pilot Study on the Concentration, Distribution and Bioaccumulation of Polybrominated Diphenyl Ethers (PBDEs) in Tissues and Organs of Grassland Sheep

Polybrominated diphenyl ether (PBDE) concentrations in various tissues and organs of grassland sheep from Inner Mongolia, China, were determined. The abilities of PBDEs binding to ovine serum albumin (OSA) and Cytochrome P450 enzyme (CYP3A24) were assessed by fluorescence spectroscopy and molecular docking simulations. The PBDE concentrations in the sheep tissue and organ samples were 33.4-167 pg/g dw. The distribution of PBDEs in sheep organs and tissues is affected not only by the function of organs and tissues, but also by the characteristics of PBDEs. Adipose tissue tends to bioaccumulate more-brominated BDEs (BDE-154, -153, and -183), but muscle tissues and visceral organs mainly bioaccumulate less-brominated BDEs. The distribution of PBDEs in visceral organs is mainly affected by the transport of ovine serum albumin (OSA) and the metabolism of CYP3A24 enzyme. The distribution of PBDEs in adipose tissue and brain is mainly affected by their logKOW.

Efficient Degradation of Printing and Dyeing Wastewater by Lotus Leaf-Based Nitrogen Self-Doped Mesoporous Biochar Activated Persulfate: Synergistic Mechanism of Adsorption and Catalysis

The discharge of printing and dyeing wastewater has been increasing, causing serious environmental pollution with the rapid development of the industry. Based on this, an N self-doped mesoporous lotus leaf biochar (LLC800) was prepared from lotus leaves as raw material for the activation of Persulfate (PS) to degrade wastewater from printing and dyeing. The removal rate of AO7 by PS, LLC800 and LLC800/PS systems were 0.84%, 31.11% and 99.46%, respectively. Electron paramagnetic resonance spectroscopy (EPR) and quench tests showed the presence of free radicals (•OH, SO4●− and O2●−) and nonradical (1O2) in the LLC800/PS system, where nonradicals (1O2) play an important role in the degradation of AO7. The “N self-doped” effect formed by the high N content of lotus leaves is the main factor leading to the high adsorption and catalytic performance of lotus leaf biochar. The effect of pyrolysis temperature on the performance of biochar can be attributed to the change of N content and conformation and specific surface area in biochar. Moreover, the LLC800/PS system has a strong resistance to interference. This work can provide technical support for the preparation of high-performance adsorption-catalytic biochar and the development of high-performance activation materials for persulfate.

An ICT-Based Coumarin Fluorescent Probe for the Detection of Hydrazine and Its Application in Environmental Water Samples and Organisms

As an inorganic small molecule pollutant, the toxicity and potential carcinogenicity of hydrazine (N₂H₄) are of increasing concern. In this work, A water-soluble fluorescent probe (OCYB) based on the intramolecular charge transfer (ICT) mechanism for the detection of hydrazine was designed and synthesized. Taking the advantage of 4-bromobutyryl as the recognition group, the high selectivity of OCYB to N₂H₄ was confirmed by steady-state fluorescence spectroscopy. The limit of detection (LOD) was calculated to be 78 nM in the DMSO-HEPES (pH 7.4) system. The detection mechanism was verified by NMR, HRMS and density functional theory (DFT) calculations. In addition, OCYB exhibits strong anti-interference ability and an “Off-On” fluorescence enhancement effect. Importantly, OCYB can be used to effectively monitor the fluorescence distribution of N₂H₄ in environmental water samples and organisms.