Chiral selenium nanoregulator capable of improving plant resistance to lithium stress, and preparation method and application thereof
By preparing and applying chiral selenium nanoparticles, the problem of plant resistance to lithium pollution was solved, the toxicity of lithium stress to plants was reduced, and the effects of plant growth protection and yield increase were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANGZHOU INST FOR ADVANCED STUDY UCAS
- Filing Date
- 2026-03-04
- Publication Date
- 2026-06-12
Smart Images
Figure CN122181542A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of nanomaterials technology, and in particular to a chiral selenium nano-regulator that can improve plant resistance to lithium stress, its preparation method, and its application. Background Technology
[0002] In 2023, global lithium production totaled 180,000 tons, with lithium-ion batteries accounting for 87%, ceramics and glass for 4%, and lubricating greases for 2%. Lithium is widely distributed in soils and its distribution is influenced by the type of soil-forming rocks and mineral composition. Lithium is readily translocated from soil systems to agricultural plants and has high bioavailability; however, its impact on human health through bioaccumulation and nutrient translocation via the food chain remains largely unknown.
[0003] Lithium has significant biological importance for humans and animals because it interferes with various biological processes, such as inducing bipolar effects, depolarizing neurons, altering neurotransmitters, and blocking neuronal ion channels. Currently, lithium is used as a pharmacological agent for treating bipolar disorder because it primarily acts on the central nervous system and interferes with neuronal activity. In addition to its positive effects on humans and animals, lithium can also cause numerous health problems in different organs, including tremors, edema, arrhythmias, gastrointestinal disturbances, and hypothyroidism. Studies have shown that high concentrations of lithium have significant toxic effects on plants; for example, corn plants exposed to greater than 40 mg / L... -1 Physiological indicators of lithium production decreased significantly by 24%; similarly, Hawrylak-Nowak et al. found that application of 50 mM Li reduced the assimilatory organ area of sunflower and maize plants by 27% and 31%, respectively. Earlier reports indicated that Solanaceae plants exhibited tolerance to lithium.
[0004] Selenium is an essential trace element for both humans and plants, playing a crucial role in maintaining anti-cancer and antioxidant functions in the human body. Selenium can also reduce the absorption of heavy metals by plants. Selenium nanoparticles (SeNPs) exhibit lower toxicity and higher biocompatibility compared to traditional organic or inorganic selenium compounds. However, chemically synthesized naked SeNPs are highly unstable, readily aggregating and precipitating in aqueous solutions, resulting in low bioactivity. To improve formulation stability and therapeutic efficacy, researchers have explored several methods for modifying or functionalizing SeNPs. As a novel nanomaterial, selenium nanoparticles possess low biotoxicity and can effectively improve plant tolerance to heavy metals (such as cadmium), thus showing great potential for application in agriculture. Domestic and international studies have shown that appropriate amounts of exogenous selenium can promote plant growth and enhance their antioxidant capacity and resistance to stress. Studies have reported that selenium has a significant positive effect on rice growth in cadmium-contaminated soil: selenium supplementation reduced cadmium accumulation in rice roots (11.8-20.6%) and stems (19.9-29.1%) by 16.3% (11.8-20.6%) and 24.6% (19.9-29.1%), respectively.
[0005] Compared to traditional inorganic selenium (such as sodium selenite and sodium selenate), selenium nanoparticles offer unique advantages. They possess a larger specific surface area, higher reactivity, and smaller particle size, enabling more efficient absorption by plants. Furthermore, selenium nanoparticles exhibit low biotoxicity, allowing them to exert their effects without affecting normal plant growth. Studies by Peng et al. (Peng D, Zhang J, Liu Q, et al. Size effect of elemental selenium nanoparticles (Nano-Se) at supranutritional levels on selenium accumulation and glutathione S-transferase activity[J]. Journal of Inorganic Biochemistry, 2007, 101(10):1457-1463.DOI:10.1016 / j.jinorgbio.2007.06.021.) and Zhang et al. (Zhang Yuzhu, Wang Bingyi, Zeng Ziao, et al. Culture conditions and bioactivity analysis of selenium nanoparticles of different sizes formed by Lactobacillus plantarum reduction[J]. Food Science, 2020, 41(22):119-126.) have shown that the surface effect and small size effect of selenium nanoparticles make them more advantageous than traditional selenium fertilizers in improving plant health and promoting growth.
[0006] In recent years, the application of selenium nanoparticles in addressing heavy metal pollution has attracted widespread attention. Studies have shown that selenium nanoparticles can effectively reduce the absorption of heavy metals by plants, decrease the accumulation of heavy metals in plants, and thus mitigate the toxicity of heavy metals to plants. Existing research indicates that exogenous application of selenium sources (such as sodium selenite, sodium selenate, and selenium nanoparticles) can significantly reduce the heavy metal content in plants such as rice, tobacco, and rapeseed.
[0007] Although the above studies have shown that traditional inorganic selenium can effectively reduce the accumulation of heavy metals in plants, selenium nanoparticles have greater application potential than traditional selenium fertilizers due to their smaller particle size, higher surface activity, and stronger bioavailability. Summary of the Invention
[0008] This invention provides a chiral selenium nanoparticle and its preparation method. The chiral selenium nanoparticle of this invention can significantly improve the plant's resistance to lithium pollution.
[0009] The technical solution of the present invention is as follows: A method for preparing chiral selenium nanoparticles includes the following steps: mixing an aqueous solution of selenium source and a chiral ligand solution evenly, adding a reducing agent to the mixed solution under stirring, and stirring the reaction for 60-150 min; centrifuging the reaction solution, collecting the precipitate, and washing to obtain chiral selenium nanoparticles; wherein the chiral ligand is D-cysteine.
[0010] Preferably, the selenium source aqueous solution is a SeO2 aqueous solution; and the reducing agent is NaBH4.
[0011] Preferably, the mixed solution of the selenium source aqueous solution and the chiral ligand solution further contains a stabilizer, wherein the stabilizer is polyvinylpyrrolidone; the average molecular weight of polyvinylpyrrolidone is 5000-20000.
[0012] More preferably, based on raw materials, the concentration of selenium source in the reaction system is 0.001-0.5 mol / L, the concentration of chiral ligand is 10-100 mmol / L, the concentration of stabilizer is 0.1-10 mg / mL, and the concentration of reducing agent is 1-10 mmol / L.
[0013] Preferably, during the stirring reaction, the stirring speed is 1000-2000 rpm.
[0014] The present invention also provides chiral selenium nanoparticles prepared by the above preparation method.
[0015] Preferably, the chiral selenium nanoparticles have a particle size of 80-150 nm; the XRD pattern of the chiral selenium nanoparticles has diffraction peaks at 2θ = 23.498° and 29.681°.
[0016] The present invention also provides a plant-based chiral selenium nanoparticle regulator, wherein the plant-based chiral selenium nanoparticle regulator contains the chiral selenium nanoparticles.
[0017] The present invention also provides the application of the chiral selenium nanoparticles or plant chiral selenium nano-regulators in plant cultivation, including: diluting the chiral selenium nanoparticles or plant chiral selenium nano-regulators to a concentration of 25-150 mg / L and spraying them on the leaves of plants.
[0018] Preferably, the plant is leafy green vegetable.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The preparation method of this invention is simple, stable, and controllable, effectively synthesizing chiral selenium nanoparticles. These chiral selenium nanoparticles can significantly reduce the cumulative lithium concentration in plant leaves, effectively alleviate plant weight loss, and maintain the selenium content within the leaves at a stable level, providing an efficient solution for lithium-resistant plant cultivation. Attached Figure Description
[0020] Figure 1 TEM images of the SeNPs synthesized in Comparative Example 2; Figure 2 This is a photograph of the aged reaction solution in Comparative Example 3; Figure 3 This is a photograph of the aged reaction solution in Comparative Example 4; Figure 4 The UV-Vis absorption spectra of L-SeNPs, D-SeNPs, and L / D-SeNPs synthesized in Examples 1-3 are shown below. Figure 5 The zeta potential diagrams are for L-SeNPs, D-SeNPs, and L / D-SeNPs synthesized in Examples 1-3. Figure 6 The X-ray diffraction patterns of L-SeNPs, D-SeNPs, and L / D-SeNPs synthesized in Examples 1-3 are shown below. Figure 7 The images shown are TEM and HRTEM images of the L-SeNPs synthesized in Example 1. Figure 8 The images shown are TEM and HRTEM images of the D-SeNPs synthesized in Example 2. Figure 9 TEM and HRTEM images of the L / D-SeNPs synthesized in Example 3; Figure 10 The circular dichroism chromatograms are of L-SeNPs, D-SeNPs, and L / D-SeNPs synthesized in Examples 1-3; Figure 11 The graph shows the lithium content in the leaves of Chinese cabbage in different treatment groups. B is the blank control group, C is the lithium stress control group, and L and M are the low selenium concentration experimental group and the medium selenium concentration experimental group, respectively. Different lowercase letters indicate significant differences between treatments (P < 0.05, Duncan multiple comparisons). Figure 12 The graph shows the selenium content in the leaves of Chinese cabbage under different treatment groups. B is the blank control group, C is the lithium stress control group, and L and M are the low selenium concentration experimental group and the medium selenium concentration experimental group, respectively. Different lowercase letters indicate significant differences between treatments (P < 0.05, Duncan multiple comparisons). Figure 13 The figures show the whole plant fresh weight of Chinese cabbage in different treatment groups. B is the blank control group, C is the lithium stress control group, and L and M are the low selenium concentration experimental group and the medium selenium concentration experimental group, respectively. Different lowercase letters indicate significant differences between treatments (P < 0.05, Duncan multiple comparisons). Detailed Implementation
[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not limit it in any way.
[0022] Comparative Example 1 At room temperature, 5.55 mg of SeO2 was added to 10 mL of 0.067 M L-penicillamine or D-penicillamine aqueous solution and stirred thoroughly. The mixture was then stirred with 10 mL of 0.6 M Na2S2O3 aqueous solution at 750 rpm for 5 min. After the reaction was complete, the solution was centrifuged at 12000 rpm for 15 min to remove impurities. The precipitate was washed three times and the solution was retained to obtain SeNPs.
[0023] The reaction was found to have no color change after completion, indicating that the synthesis failed.
[0024] Comparative Example 2 At room temperature, 5.55 mg of SeO2 was added to 10 mL of a 10 mg / mL aqueous solution of polyvinylpyrrolidone (PVP) and stirred thoroughly. The mixture was then stirred with 10 mL of a 0.6 M aqueous solution of Na2S2O3 at 750 rpm for 5 min. After the reaction was complete, the mixture was centrifuged at 12000 rpm for 15 min to remove impurities. The precipitate was washed three times and retained to obtain SeNPs.
[0025] TEM images of synthesized SeNPs are shown below. Figure 1 As shown, no obvious nanoparticle morphology was observed in the TEM image, and the material appeared to be relatively aggregated.
[0026] Comparative Example 3 At room temperature, with stirring at 100 rpm, 15 mM L-cysteine aqueous solution (30 mL) was added dropwise to 5 mM H2SeO3 aqueous solution (30 mL) and allowed to react for 150 min and aged for 120 min.
[0027] Photos of the reaction solution after aging are shown below. Figure 2 As shown, the liquid colors are uneven, indicating an incomplete reaction.
[0028] Comparative Example 4 At room temperature, with stirring at 100 rpm, 0.05 mol / L L-cysteine (30 mL) was added dropwise to 0.1 mol / L H2SeO3 (30 mL) and allowed to react for 150 min, followed by aging for 120 min.
[0029] Photographs of the reaction solution after aging are shown below. Figure 3 As shown, no color change occurred, and the synthesis failed.
[0030] Example 1 At room temperature, with stirring at 1200 rpm, 2 mL of 0.1 mol / L SeO2 aqueous solution and 15 mL of 90.46 mmol / L L-cysteine were simultaneously added to 1 mL of 50 mg / mL polyvinylpyrrolidone (average molecular weight 10000). The mixture was reacted for 10 min. Then, with stirring at 1400 rpm, 5 mL of 27 mmol / L NaBH4 was added to the reaction solution, and the reaction was continued for 120 min. After the reaction was complete, the mixture was centrifuged at 8000 rpm for 15 min to remove impurities. The precipitate was washed three times and retained to obtain L-SeNPs.
[0031] Example 2 At room temperature, with stirring at 1200 rpm, 2 mL of 0.1 mol / L SeO2 aqueous solution and 15 mL of 90.46 mmol / L D-cysteine were simultaneously added to 1 mL of 50 mg / mL polyvinylpyrrolidone (average molecular weight 10000). The mixture was reacted for 10 min. Then, with stirring at 1400 rpm, 5 mL of 27 mmol / L NaBH4 was added to the reaction solution, and the reaction continued for 120 min. After the reaction was complete, the mixture was centrifuged at 8000 rpm for 15 min to remove impurities. The precipitate was washed three times and retained to obtain D-SeNPs.
[0032] Example 3 At room temperature and with a stirring speed of 1200 rpm, 2 mL of 0.1 mol / L SeO2 aqueous solution and 10 mL of 67.83 mmol / L L-cysteine were simultaneously added to 1 mL of 50 mg / mL polyvinylpyrrolidone (average molecular weight 10000). The mixture was allowed to react for 5 min, followed by 5 mL of 135.7 mmol / L D-cysteine aqueous solution and a further 5 min reaction. Then, 5 mL of 27 mmol / L NaBH4 was added to the reaction solution with a stirring speed of 1400 rpm, and the reaction was continued for 120 min. After the reaction was complete, the mixture was centrifuged at 8000 rpm for 15 min to remove impurities. The precipitate was washed three times and retained to obtain L / D-SeNPs.
[0033] The following characterization methods confirmed the synthesis of different chiral selenium nanoparticles.
[0034] 1. Ultraviolet-Visible Absorption Spectroscopy Analysis The spectra of SeNPs with different chiralities were scanned using a UV-Vis spectrophotometer, and the results are as follows: Figure 4 As shown, all three chiral configurations of selenium nanoparticles exhibit a characteristic absorption peak at 255 nm, which corresponds to the surface plasmon resonance absorption of selenium nanoparticles. The absorption peak positions of L-SeNPs and L / D-SeNPs are basically the same, while the absorption peak of D-SeNPs shows a slight blue shift, indicating that the difference in chiral configuration has a certain influence on the optical properties of selenium nanoparticles.
[0035] 2. Dynamic light scattering analysis of particle size and zeta potential The hydration kinetic diameter of selenium nanoparticles was determined using a dynamic light scattering particle size analyzer (DLS), and the results are shown in Table 1. The average particle sizes of L-SeNPs, D-SeNPs, and L / D-SeNPs were 150.3 nm, 152.2 nm, and 144.2 nm, respectively. There was no significant difference in particle size between L-SeNPs and D-SeNPs, while the particle size of L / D-SeNPs was slightly smaller.
[0036] Table 1 Note: Particle size was tested three times for each sample, and the average value was taken.
[0037] Simultaneously, the dynamic light scattering particle size analyzer can also measure the zeta potential of nano-selenium, and the results are as follows: Figure 5As shown, the Zeta potentials of L-SeNPs, D-SeNPs, and L / D-SeNPs are -73.55 mV, -59.73 mV, and -60.57 mV, respectively, all with absolute values greater than 50 mV. This indicates that the three types of selenium nanoparticles exhibit good electrostatic repulsion stability in solution and are not prone to aggregation. The absolute value of the Zeta potential of L-SeNPs is slightly higher than that of D- and L / D-SeNPs, suggesting that it has a higher surface charge density and may have stronger stability.
[0038] 3. X-ray diffraction analysis The crystal structure of nano-selenium was analyzed using X-ray diffraction (XRD), and the results are as follows: Figure 6 As shown. The XRD patterns of L-SeNPs, D-SeNPs and L / D-SeNPs show that all three chiral selenium nanoparticles have characteristic diffraction peaks at 2θ = 23.498° and 29.681°, respectively, which correspond to the (100) and (101) crystal planes of hexagonal selenium (h-Se) on the standard card (PDF#82-2246), indicating that crystalline selenium nanoparticles were successfully synthesized.
[0039] 4. Morphological observation using transmission electron microscopy The microstructures of different chiral selenium nanoparticles were observed using transmission electron microscopy. The results for L-SeNPs, D-SeNPs, and L / D-SeNPs are as follows: Figure 7 , 8 As shown in Figures 9 and 1, L-SeNPs and D-SeNPs exhibit regular hexagonal or near-hexagonal plate-like morphologies with relatively uniform particle size, ranging from approximately 80 to 120 nm in diameter. They have clear edges, good crystallinity, and no obvious agglomeration. L / D-SeNPs, in addition to some hexagonal particles, also show some irregular, near-spherical, or short rod-shaped nanostructures with a slightly wider size distribution and some particles exhibiting slight agglomeration. HRTEM images of all three samples show clear lattice fringes, and the measured interplanar spacing is 3.45 Å. This value is close to the 100 plane (d=3.78 Å) and 101 plane (d=3.01 Å) of hexagonal selenium (h-Se) crystals, indicating that the synthesized nano-selenium has good crystallinity, and the difference in chiral configuration has no significant effect on the lattice structure.
[0040] 5. Circular dichroism chiral optical activity analysis The chiral optical activity of different chiral selenium nanoparticles was characterized using circular dichroism spectroscopy (CD), and the results are as follows: Figure 10As shown, L-SeNPs and D-SeNPs exhibit mirror-symmetry in their spectra, indicating the successful synthesis of enantioselective chiral selenium nanoparticles. L / D-SeNPs show no significant CD signal at this wavelength, consistent with the optical characteristics of racemic compounds. This result confirms that L-cysteine and D-cysteine were successfully used as chiral ligands to induce the chiral optical activity of selenium nanoparticles, with a one-to-one correspondence between the chiral configuration and the CD signal direction.
[0041] Application examples L-SeNPs, D-SeNPs, and L / D-SeNPs were used as selenium regulators for the plants, and Chinese cabbage (Suzhou green) was planted according to the information in Table 2. Samples were harvested after 55 days of cultivation, and selenium regulators were applied twice during the cultivation process.
[0042] The control group (Blank) had no lithium or selenium regulator applied to the soil; the lithium stress control group (Control) had lithium applied to the soil (soil with a lithium concentration of 43.56 mg / kg) and no selenium regulator applied; the low-concentration selenium experimental group (L) had lithium applied to the soil (soil with a lithium concentration of 43.56 mg / kg) and foliar spraying with 25 mg / L of L-SeNPs, D-SeNPs, or L / D-SeNPs; the medium-concentration selenium experimental group (M) had lithium applied to the soil (soil with a lithium concentration of 43.56 mg / kg) and foliar spraying with 100 mg / L of L-SeNPs, D-SeNPs, or L / D-SeNPs.
[0043] Table 2 Samples were harvested 55 days after transplanting. The plants were completely removed from the pots and rinsed repeatedly with deionized water and (1 x) PBS solution to remove surface soil. The surface moisture was then absorbed using absorbent paper. The weight of the whole plant was weighed and recorded. Approximately 0.5 g of green leaves was weighed using a scalpel, recorded, and preserved for lithium content determination.
[0044] Method for determining lithium and selenium concentrations in leafy green vegetables: The leaves were digested using microwave digestion, and then the lithium and selenium content was determined using ICP-MS.
[0045] Dissolution method: Use a spatula or paper trough to transfer the sample to the bottom of the PTFE digestion tube, taking care to avoid sample adhering to the tube walls. Add 6.5 mL of 65% analytical grade nitric acid (HNO3) and 1.3 mL of 30% hydrogen peroxide (H2O2) sequentially.
[0046] The digestion tube was placed on a heating plate (BHW-09A45, Shanghai Botong Chemical Technology Co., Ltd.) and pre-digested at 130℃ for 45 min with the opening open. After pre-digestion, the digestion tube was removed, allowed to cool to room temperature, and the tube cap was tightened. The digestion tube was then placed in a high-throughput microwave digester (Multiwave 5000 CN, Anton Paar GmbH, Austria) and microwave digestion was performed according to the digestion program set in Table 3.
[0047] After microwave digestion, remove the digestion tube, place it in a fume hood with the cap open, and return it to the heating plate. Heat at 160℃ for approximately 90 minutes to remove acid, until about 0.5 mL of solution remains in the tube. Transfer the digest to a 15 mL centrifuge tube and dilute to 10 mL with 2.5% HNO3 solution, mixing well. Filter an appropriate amount of the digest through a 0.45 μm polyethersulfone (PES) syringe filter into a sample vial. Dilute appropriately according to the sample concentration and analyze using inductively coupled plasma mass spectrometry (ICP-MS). A blank control was also prepared and digested along with the sample.
[0048] Table 3 ICP-MS / MS Determination Methods and Quality Control: The tests were conducted using an inductively coupled plasma mass spectrometer (Agilent 8900, Agilent Technologies, USA).
[0049] After the instrument stabilized during startup, Agilent ICP-MS tuning fluid (1 ppb) was used to optimize its performance. Parameters such as lens voltage and nebulizer flow rate were adjusted to ensure optimal sensitivity and oxide yield (CeO₂). + / Ce + < 2%), double charge yield (Ce 2+ / Ce + Indicators such as <3% meet the testing requirements.
[0050] Lithium (Li) and selenium (Se) standard solutions were prepared using a mixed lithium and selenium standard solution (1000 μg / mL, National Center for Analysis and Testing of Nonferrous Metals and Electronic Materials). A series of standard working solutions were prepared by serial dilution, with concentration gradients of 0, 1, 2, 5, 10, 20, 50, 100, and 200 μg / L (ppb). Rhodium (… 103 Rh was used as the internal standard element. A rhodium standard solution (1000 μg / mL, National Center for Analysis and Testing of Nonferrous Metals and Electronic Materials) was used to prepare the internal standard solution, which was added simultaneously through a three-way tube to ensure a final internal standard concentration of 1 mg / L (ppm) entering the instrument, which was maintained constant throughout the process. A standard curve was plotted with the mass concentration of the standard series on the x-axis and the ratio of the analyte count to the internal standard count on the y-axis. The linear correlation coefficient (R0) was required.2 The resistivity was ≥0.999. The tubing was cleaned using 2.5% HNO3 solution during sample measurement intervals to eliminate cross-contamination. All experimental water was ultrapure water (resistivity 18.2 MΩ·cm).
[0051] To ensure the accuracy and reliability of the test results, the following quality control measures are adopted: Blank control: Each digestion includes a blank sample (without adding any sample, digestion and determination are performed simultaneously), and the content is calculated after deducting the blank value from the sample measurement value; Spike recovery test: A portion of the samples are randomly selected, and a certain amount of lithium and selenium standard solution is added before digestion. The spike recovery rate is calculated, and the recovery rate is required to be between 80% and 120%.
[0052] The lithium and selenium content in the sample is calculated using the following formula: Where: C is the content of the element to be tested in the sample (mg / kg); C1 is the concentration of the element to be tested in the sample solution obtained from the standard curve (μg / L, ppb); C0 is the concentration of the element to be tested in the blank solution (μg / L, ppb); V is the final volume of the sample (mL); f is the dilution factor; m is the sample weight (g); 10 -3 This is a unit conversion factor (to convert μg / L to mg / kg).
[0053] Figure 11 This study demonstrates the effects of different selenium treatments on lithium content in Chinese cabbage leaves. The lithium stress control group (C) showed a significantly increased lithium content in its leaves, reaching 79.61 mg / kg, while the blank group (B) had only 4.27 mg / kg, indicating that lithium stress was successfully established. Compared with group C, all selenium treatment groups significantly reduced leaf lithium content (p < 0.05). Specifically, the DM group (dextrose selenium, 100 mg / L) had a leaf lithium content of 39.50 mg / kg, significantly lower than group C, with a reduction of 50.4%. This was not significantly different from the LM group (47.75 mg / kg) and the L / DM group (53.03 mg / kg), indicating that the DM treatment had a stable lithium-reducing effect.
[0054] Figure 12This study demonstrates the accumulation of selenium in leafy greens under different treatments. The control group (B) and the lithium stress group (C) showed extremely low selenium content in their leaves (<0.01 mg / kg), indicating no exogenous selenium input. The selenium content in the leaves of all selenium treatment groups increased to varying degrees. The selenium content in the DM group was 0.33 mg / kg, which was at the same significant level (class b) as the LM group (0.28 mg / kg), L group, and D group, and significantly lower than the 1.34 mg / kg in the L / DM group (class a). The excessively high selenium content in the L / DM group may pose a food safety risk. The DM group, while ensuring lithium reduction and yield increase, controlled the leaf selenium content within a safe range, avoiding the risk of excessive selenium.
[0055] Figure 13 This study reflects the effects of different treatments on the plant weight at the end of the growing season for Chinese cabbage. The plant weight in the lithium stress control group (C) significantly decreased to 28.67 g, a 35.1% reduction compared to the blank group B (44.15 g), indicating that lithium stress had a significant inhibitory effect on Chinese cabbage growth. The plant weight in the DM group (dextrose selenium, 100 mg / L) was 45.53 g, not significantly different from the blank group B, but significantly higher than both the C group and the LM group (28.91 g), indicating that DM treatment not only alleviated the growth inhibition caused by lithium stress but also achieved a significant yield increase. The L / DM group (45.22 g) also showed a similar yield-increasing effect, but combined with… Figure 3 Analysis suggests that its excessively high selenium content poses a potential risk.
[0056] In summary, DM treatment (dextrose selenium, 100 mg / L) demonstrated significant advantages in reducing lithium content in cabbage leaves, restoring and increasing yield, and controlling leaf selenium content within a safe range. Compared to the lithium-stressed group, the DM group showed a 50.4% reduction in leaf lithium content, restored plant weight to the control group level, and a leaf selenium content of only 0.33 mg / kg, far below the food safety risk threshold. Therefore, DM treatment can serve as an effective regulatory measure for the safe production of cabbage in lithium-contaminated farmland and has promising application prospects.
[0057] Experimental results show that, compared with the control group, the application of medium concentration (100 mg / L) of dextrorotatory chiral selenium nanoparticles can significantly reduce the lithium accumulation concentration in the leaves of Chinese cabbage, effectively alleviate plant weight loss, and maintain the selenium content inside the leaves at a stable level, providing an efficient solution for lithium-resistant cultivation of Chinese cabbage.
[0058] The preparation method of this invention is stable and controllable, effectively synthesizing different chiral selenium nanoparticles, and has a positive effect on combating lithium pollution in green vegetables, including reducing lithium concentration and slowing down plant weight loss.
[0059] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing chiral selenium nanoparticles, characterized in that, Includes the following steps: The selenium source aqueous solution and the chiral ligand solution were mixed evenly, and a reducing agent was added to the mixed solution under stirring. The mixture was stirred for 60-150 min. The reaction solution was centrifuged, the precipitate was collected and washed to obtain chiral selenium nanoparticles. The chiral ligand was D-cysteine.
2. The method for preparing chiral selenium nanoparticles according to claim 1, characterized in that, The selenium source aqueous solution is a SeO2 aqueous solution; the reducing agent is NaBH4.
3. The method for preparing chiral selenium nanoparticles according to claim 1, characterized in that, The mixed solution of the selenium source aqueous solution and the chiral ligand solution also contains a stabilizer, namely polyvinylpyrrolidone; the average molecular weight of polyvinylpyrrolidone is 5000-20000.
4. The method for preparing chiral selenium nanoparticles according to claim 3, characterized in that, Based on the raw materials, the concentration of selenium source in the reaction system is 0.001-0.5 mol / L, the concentration of chiral ligand is 10-100 mmol / L, the concentration of stabilizer is 0.1-10 mg / mL, and the concentration of reducing agent is 1-10 mmol / L.
5. The method for preparing chiral selenium nanoparticles according to claim 1, characterized in that, During the reaction, the stirring speed is 1000-2000 rpm.
6. A chiral selenium nanoparticle prepared by the preparation method according to any one of claims 1-5.
7. The chiral selenium nanoparticles according to claim 6, characterized in that, The chiral selenium nanoparticles have a particle size of 80-150 nm; the XRD pattern of the chiral selenium nanoparticles has diffraction peaks at 2θ = 23.498° and 29.681°.
8. A plant-based chiral selenium nano-regulator, characterized in that, The plant-based chiral selenium nanoparticle regulator contains the chiral selenium nanoparticles as described in claim 6 or 7.
9. The application of the chiral selenium nanoparticles of claim 6 or 7 or the plant chiral selenium nano-regulator of claim 8 in plant cultivation, characterized in that, include: The chiral selenium nanoparticles or plant chiral selenium nano-regulators are diluted to a concentration of 25-150 mg / L and sprayed onto the leaves of the plants.
10. The application according to claim 9, characterized in that, The plant in question is a leafy green vegetable.