Multifunctional nano material Ni-MoS2 (at) Au for detecting trace toxic substances in mushrooms and preparation method

Abstract

The invention provides a multifunctional nano material Ni-MoS2 (at) Au for detecting trace toxic substances in mushrooms and a preparation method of the multifunctional nano material Ni-MoS2 (at) Au. The nano material is prepared from a metal oxide, a surfactant, precious metal nano particles and a solvent, the nano material has colorimetric and Raman detection functions on various trace toxic substances (mercury ions and amanita peptide) in mushrooms, hydrogen peroxide is immediately catalyzed to quickly oxidize 3, 3 ', 5, 5'-tetramethyl benzidine into yellow 3, 3 ', 5, 5'-tetra (tetrafluoromethyl) phenyl diamine oxide after the nano material is in contact with a target object Hg < 2 + > for 1s in a colorimetric mode, the nano material has an extremely low detection limit of 0.036 mu g / mL, and the nano material can be used for detecting various trace toxic substances (mercury ions and amanita peptide) in mushrooms. The catalyst has good selectivity and is not interfered by other heavy metal ions; in a Raman mode, high-sensitivity detection of alpha-amanita peptide and beta-amanita peptide can be realized, and the detection limit ranges are 10 <-4 > M to 10 <-8 > M. The nano material provides a reference mode capable of detecting multiple target objects in the same system, and opens up a new way for a detection strategy of trace toxic substances in the field of food safety detection.

Description

Technical Field

[0001] This invention belongs to the field of analytical detection and provides a multifunctional nanomaterial Ni-MoS2@Au for detecting trace amounts of toxic substances in mushrooms and its preparation method. Background Technology

[0002] Trace amounts of toxic substances in mushrooms mainly include heavy metal ions (Hg). 2+ In addition to toxins such as amatoxins (e.g., phytotoxicants) and biotoxins (e.g., amatoxins), these toxins typically interact with enzymes and proteins in organisms, causing them to become inactive or disrupt their synthesis, leading to damage to the nervous system, fulminant hepatic failure, coma, and death. Therefore, accurately and effectively detecting the various toxic substances in wild mushrooms is crucial for reducing or preventing their harm to human health and ensuring food safety.

[0003] Currently, a series of analytical techniques have been developed for the detection of amatoxins or heavy metal ions, including inductively coupled plasma mass spectrometry (Chemical Engineering Journal, 2021, 420, 130414), atomic fluorescence spectrometry (Microchemical Journal, 2018, 143, 228), electrochemical analysis (Biosensors and Bioelectronics 2024, 262, 116568; Analytica Chimica Acta, 2024, 1326, 343136), colorimetric analysis, Raman spectroscopy, and other spectroscopic analysis techniques. Among these, spectroscopic analysis techniques have received widespread attention due to their advantages such as high sensitivity, simple operation, and fingerprint analysis.

[0004] To date, researchers have designed and synthesized various sensing materials based on spectral analysis techniques for the detection of heavy metal ions, but research on amatoxins is limited. For example, Professor Ai Shiyun's research group at Shandong Agricultural University designed a self-assembled monolayer gold nanocube membrane to detect Hg. 2+ Colorimetric-Raman detection; Professor Tong Yexiang's research group at Sun Yat-sen University designed gold nanorods modified with thymine to achieve Hg 2+ Raman detection of Hg (Microchemical Journal, 2021, 161, 105790; Nanomaterials 2017, 7, 192); Professor Renjith P. Johnson's research group designed a method using gold nanoparticles to achieve the detection of Hg. 2+Colorimetric detection (ACS Appl. Polym. Mater. 2023, 5, 6377), etc., these sensing materials cannot meet the requirements for simultaneous detection of multiple trace toxic substances in mushroom systems, and are easily affected by other interferences and environmental factors, so the detection accuracy needs to be improved.

[0005] Therefore, based on the fact that the same optical sensing material exhibits different detection modes for different targets, it not only possesses characteristics such as high sensitivity and strong anti-interference ability, but also facilitates visual observation of the target. To date, there are few studies on the colorimetric and Raman detection of multiple trace toxic substances in mushrooms using the same material. Therefore, it is particularly important to develop easily prepared, low-cost, and highly sensitive colorimetric and Raman detection optical sensing materials for multiple trace toxic substances in mushrooms.

[0006] This invention develops a multifunctional nanomaterial for detecting trace amounts of toxic substances in mushrooms. The colorimetric detection principle involves adding the synthesized nanomaterial as a peroxide-like nanoenzyme solution to the target substance Hg. 2+ The synthesized nanomaterial can catalyze the rapid oxidation of 3,3',5,5'-tetramethylbenzidine to a yellow 3,3',5,5'-tetra(tetrafluoromethyl)phenyldiamine monooxide using hydrogen peroxide. Its Raman detection principle is based on the fact that the synthesized nanomaterial, due to nickel doping and surface modification with gold nanoparticles, enhances the interfacial charge transfer efficiency, thereby strengthening the Raman effect and effectively amplifying the Raman spectral signal of trace toxic substances, achieving sensitive detection. The colorimetric mode of this nanomaterial is characterized by its speed, sensitivity, and high specificity, while the Raman mode is non-destructive and highly sensitive. Summary of the Invention

[0007] The present invention aims to provide a multifunctional nanomaterial Ni-MoS2@Au for detecting trace toxic substances in mushrooms and its preparation method. This nanomaterial is composed of metal oxides, surfactants, noble metal nanoparticles, and solvents. The nanomaterial exhibits colorimetric and Raman detection capabilities for various trace toxic substances (mercury ions and amatoxins) in mushrooms. In colorimetric mode, it reacts with the target analyte Hg. 2+ Immediately upon contact (1 second), hydrogen peroxide catalyzes the rapid oxidation of 3,3',5,5'-tetramethylbenzidine to a yellow 3,3',5,5'-tetra(tetrafluoromethyl)phenyldiamine monooxide, exhibiting an extremely low detection limit of 0.036 μg / mL and good selectivity, unaffected by interference from other heavy metal ions. In Raman mode, highly sensitive detection of α-amanitin and β-amanitin is achieved, with detection limits ranging from 10 μg / mL for both. -4 M-10 -8 M. This nanomaterial provides a reference model for detecting multiple targets in the same system, opening up new avenues for the detection strategies of trace toxic substances in the field of food safety testing.

[0008] The present invention discloses a multifunctional nanomaterial Ni-MoS2@Au for detecting trace amounts of toxic substances in mushrooms. This nanomaterial is made from molybdenum disulfide (a metal oxide), polyvinylpyrrolidone (a surfactant), polyvinyl alcohol or polyethylene glycol, gold nanoparticles (a noble metal nanoparticle), and ultrapure water as a solvent. The specific operation is carried out according to the following steps: Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 to 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1-1:3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mmol / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, rapidly add 0.5-1.5 mL of sodium citrate with a concentration of 38.75 mmol / mL to the boiling solution. The gold nanoparticles generated are cooled to room temperature after 15 minutes and stored in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add a surfactant with a mass fraction of 2-2.5%, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Mix and sonicate in an ice bath for 30 minutes. Centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0009] A method for preparing Ni-MoS2@Au, a multifunctional nanomaterial for detecting trace amounts of toxic substances in mushrooms, comprises the following steps: Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 to 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1-1:3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mmol / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, rapidly add 0.5-1.5 mL of sodium citrate with a concentration of 38.75 mmol / mL to the boiling solution. The gold nanoparticles generated are cooled to room temperature after 15 minutes and stored in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add a surfactant with a mass fraction of 2-2.5%, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Mix and sonicate in an ice bath for 30 minutes. Centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0010] The trace toxic substance in the mushrooms mentioned is the heavy metal ion Hg. 2+ And the biotoxins α-amanita and β-amanita.

[0011] This invention discloses a multifunctional nanomaterial Ni-MoS2@Au for detecting trace amounts of toxic substances in mushrooms and its preparation method, primarily targeting trace amounts of heavy metal ions (Hg) in mushrooms. 2+ The method uses colorimetric and Raman spectroscopy to detect various toxic substances (such as α-amatoxins and β-amatoxins) and biotoxins (α-amatoxins and β-amatoxins), solving the current problem that the same sensing material cannot achieve sensitive and rapid detection of multiple toxic substances in different modes in the same system.

[0012] The present invention discloses a multifunctional nanomaterial Ni-MoS2@Au for detecting trace toxic substances in mushrooms and its preparation method. Compared with existing detection nanomaterials, it can realize the detection function of multiple toxic substances in the same system and has the advantages of low detection limit, strong anti-interference and short reaction time. It can provide an effective technical means for the field of food safety testing. Attached Figure Description

[0013] Figure 1 SEM image of the synthesized multifunctional detection nanomaterial; Figure 2 The synthesized nanomaterials were compared with actual samples containing Hg at concentrations ranging from 0 μg / mL to 100 μg / mL.2+ The UV-Vis absorption spectrum of the solution after the reaction is shown in the inset, which is a photograph taken with a mobile phone showing the color change of the solution after the reaction. Figure 2 The right side is based on Hg 2+ The concentration is on the x-axis and the absorbance at 450 nm is on the y-axis. The fitted equation is a linear equation in one variable. Figure 3 The bar chart shows the colorimetric specificity and anti-interference RGB values ​​of the synthesized nanomaterial at 1 mg / mL and various other heavy metal ions at a concentration of 500 mM, respectively, for the B value. Figure 4 The synthesized nanomaterials were prepared at concentrations of 1 mg / mL and in a concentration range of 10. -4 M-10 -8 The Raman spectrum of α-amanita peptide in the actual sample of M after reaction, where... Figure 4 The right side shows the Raman characteristic peak at 1074 cm⁻¹, with the concentration of α-amanitin as the x-axis. -1 and 1582 cm -1 The spectral peak intensity value is the ordinate, and the fitted linear equation is obtained. Figure 5 The synthesized nanomaterials were prepared at concentrations of 1 mg / mL and in a concentration range of 10. -4 M-10 -8 The Raman spectrum of β-amanita peptide in reagent sample M after reaction, wherein... Figure 5 The right side shows the Raman characteristic peak at 998 cm⁻¹, with β-amanitin concentration as the x-axis. -1 and 1370 cm -1 The spectral peak intensity value is used as the ordinate, and a linear equation in one variable is obtained by fitting the values. Detailed Implementation

[0014] The present invention will be further described below through specific embodiments, but the invention is not limited to these embodiments. Example 1

[0015] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 0.5 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of the gold nanoparticle solution obtained in step c. Mix and sonicate in an ice bath for 30 minutes. Centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0016] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 50 mM Hg was added. 2+ The solution was 100 μL, and the UV-Vis absorption spectrum was scanned using a UV-Vis spectrophotometer. A significant absorption peak appeared at 450 nm after the reaction. The reagent after the reaction was directly photographed, and the comparison of the reagent before and after the reaction showed that the reagent changed from colorless to yellow after the reaction. Take 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial and 1 mL of 10 mg / mL Ni-MoS2@Au nanomaterial. -4 The α-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. By comparing the spectra before and after the reaction, it can be seen that the concentration at 1074 cm⁻¹... -1 and 1582 cm -1 A distinct Raman characteristic peak appeared at the [location]; 1 mL of the prepared nanomaterial with a concentration of 1 mg / mL was mixed with 1 mL of [amount]... -4 The β-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. By comparing the spectra before and after the reaction, it can be seen that at 998 cm⁻¹... -1 and 1370cm -1 A distinct Raman characteristic peak appeared at that location. Example 2

[0017] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:2. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mmol / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, rapidly add 0.8 1% sodium citrate with a concentration of 38.75 mmol / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2.1% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au. Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. The addition of different concentrations of Hg was then tested. 2+ The subsequent UV-Vis absorption spectrum shows that: with Hg 2+ With increasing concentration, the intensity of the absorption peak at 450 nm gradually increases, and when Hg... 2+ When the concentration ranges from 0 μg / mL to 100 μg / mL, the intensity of the absorption peak at 450 nm varies with Hg. 2+The concentration increases linearly with increasing concentration, and the fitted linear equation is y = 0.01x - 0.1. According to the calculation equation for the detection limit: detection limit = 3σ / K, where σ is the standard deviation of the UV-Vis spectrophotometer used. The standard deviation of the UV-Vis spectrophotometer used in this invention is σ = 0.00012 (n = 10). Therefore, the UV detection limit of this reagent is calculated to be 0.036 μg / mL. Example 3

[0018] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 1.0 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2.2% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0019] Detection of trace toxic substances in mushrooms: 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was mixed thoroughly with 1 mL of α-amanita peptide solutions of different concentrations. Raman spectra were then collected. The Raman spectra showed that the intensity of the characteristic peak gradually increased with increasing α-amanita peptide concentration. When the α-amanita peptide concentration ranged from 10 mg / mL... -4 M-10 -8At time M, it is located at 1074 cm. -1 The characteristic peak intensity at a certain point increases linearly with increasing α-amanita peptide concentration. The fitted linear equation is y = -334.5x + 2688.4, with a correlation coefficient R0. 2 It is 0.9645; located at 1582 cm. -1 The characteristic peak intensity at a certain point increases linearly with increasing α-amanita peptide concentration. The fitted linear equation is y = -78.9x + 4836.6, with a correlation coefficient R0. 2 It is 0.9808; 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was mixed thoroughly with 1 mL of β-amanita peptide solutions of different concentrations. Raman spectra were then collected. The Raman spectra showed that the intensity of the characteristic peak gradually increased with increasing β-amanita peptide concentration. When the β-amanita peptide concentration ranged from 10 mg / mL... -4 M-10 -8 At time M, it is located at 998 cm. -1 The characteristic peak intensity at a certain point increases linearly with increasing β-amanita peptide concentration. The fitted linear equation is y = -70.7x + 792.4, with a correlation coefficient R0. 2 It is 0.9748; located at 1370 cm. -1 The characteristic peak intensity at [location] increases linearly with increasing β-amanita peptide concentration. The fitted linear equation is y = -105.8x + 1157.8, with a correlation coefficient R0. 2 It is 0.9725. Example 4

[0020] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:2 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 1.5 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add a surfactant with a mass fraction of 2.3%, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain a mixture. Then take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0021] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 100 μL of 500 mM potential interfering agents, including Ni, were added to each solution. 2+ As 3+ Cu 2+ Zn 2+ Cr 6+ Cd 2+ Mn 2+ A solution containing heavy metal ions was prepared, and after 1 second, a colorimetric photograph was taken with a mobile phone under indoor lighting conditions. The photograph shows that the nanomaterial Ni-MoS2@Au only exhibits high concentrations of heavy metal ions in Hg solutions. 2+ When present, the color changes from colorless to yellow, and other interfering substances do not respond, proving that the nanomaterial Ni-MoS2@Au has good selectivity in the colorimetric mode. Example 5

[0022] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:2 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:2. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 0.5 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2.4% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution, mix, sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0023] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 50 mM Hg was added. 2+ The solution was 100 μL, and the UV-Vis absorption spectrum was scanned using a UV-Vis spectrophotometer. A significant absorption peak appeared at 450 nm after the reaction. Direct photographs of the reagent before and after the reaction were taken, and the comparison of the photos showed that the reagent changed from colorless to yellow after the reaction. Take 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial and 1 mL of 10 mg / mL Ni-MoS2@Au nanomaterial. -4 The α-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 1074 cm⁻¹. -1 and 1582 cm -1 A distinct Raman characteristic peak appeared at the [location]; 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was mixed with 1 mL of 10 [concentration] [material]. -4 The β-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 998 cm⁻¹. -1 and 1370 cm -1 A distinct Raman characteristic peak appeared at that location. Example 6

[0024] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:2 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at a temperature of 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 0.8 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2.5% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution, mix, sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0025] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 50 mM Hg was added. 2+ The solution was 100 μL, and the UV-Vis absorption spectrum was scanned using a UV-Vis spectrophotometer. A significant absorption peak appeared at 450 nm after the reaction. Direct photographs of the reagent before and after the reaction were taken, and the comparison of the photos showed that the reagent changed from colorless to yellow after the reaction. Take 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial and 1 mL of 10 mg / mL Ni-MoS2@Au nanomaterial. -4The α-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 1074 cm⁻¹. -1 and 1582 cm -1 A distinct Raman characteristic peak appeared at the [location]; 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was taken and 1 mL of 10 [concentration] ... -4 The β-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 998 cm⁻¹. -1 and 1370 cm -1 A distinct Raman characteristic peak appeared at that location. Example 7

[0026] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220 °C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 1.0 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0027] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 50 mM Hg was added. 2+ The solution was 100 μL, and the UV-Vis absorption spectrum was scanned using a UV-Vis spectrophotometer. A significant absorption peak appeared at 450 nm after the reaction. Direct photographs of the reagent before and after the reaction were taken, and the comparison of the photos showed that the reagent changed from colorless to yellow after the reaction. Take 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial and 1 mL of 10 mg / mL Ni-MoS2@Au nanomaterial. -4 The α-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 1074 cm⁻¹. -1 and 1582 cm -1 A distinct Raman characteristic peak appeared at the [location]; 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was taken and 1 mL of 10 [concentration] ... -4 The β-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 998 cm⁻¹. -1 and 1370 cm -1 A distinct Raman characteristic peak appeared at that location. Example 8

[0028] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:2. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 1.5 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution to generate gold nanoparticles. After 15 minutes, cool at room temperature and store in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2.1% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0029] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 50 mM Hg was added. 2+ The solution was 100 μL, and the UV-Vis absorption spectrum was scanned using a UV-Vis spectrophotometer. A significant absorption peak appeared at 450 nm after the reaction. Direct photographs of the reagent before and after the reaction were taken, and the comparison of the photos showed that the reagent changed from colorless to yellow after the reaction. Take 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial and 1 mL of 10 mg / mL... -4 The α-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 1074 cm⁻¹. -1 and 1582 cm -1 A distinct Raman characteristic peak appeared at the [location]; 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was taken and 1 mL of 10 [concentration] ... -4 The β-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 998 cm⁻¹. -1 and 1370 cm -1 A distinct Raman characteristic peak appeared at that location. Example 9

[0030] Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mm / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, quickly add 0.5 mL of sodium citrate with a concentration of 38.75 mm / mL to the boiling solution. The gold nanoparticles generated are cooled to room temperature after 15 minutes and stored in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add 2.2% (w / w) of the surfactant polyvinylpyrrolidone, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate again in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution, mix, sonicate in an ice bath for 30 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

[0031] Detection of trace toxic substances in mushrooms: 100 μL of 600 μM 3,3',5,5'-tetramethylbenzidine, 150 μM hydrogen peroxide, and 1 mg / mL of the prepared Ni-MoS2@Au nanomaterial solution were added to 1.5 mL of the solution and mixed thoroughly. Then, 50 mM Hg was added. 2+ The solution was 100 μL, and the UV-Vis absorption spectrum was scanned using a UV-Vis spectrophotometer. A significant absorption peak appeared at 450 nm after the reaction. Direct photographs of the reagent before and after the reaction were taken, and the comparison of the photos showed that the reagent changed from colorless to yellow after the reaction. Take 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial and 1 mL of 10 mg / mL Ni-MoS2@Au nanomaterial. -4 The α-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 1074 cm⁻¹. -1 and 1582 cm -1 A distinct Raman characteristic peak appeared at the [location]; 1 mL of the prepared 1 mg / mL Ni-MoS2@Au nanomaterial was taken and 1 mL of 10 [concentration] ... -4 The β-amanitin M solution was thoroughly mixed and Raman spectroscopy was performed using a microconfocal Raman spectrometer. The spectra were observed at 998 cm⁻¹. -1 and 1370 cm -1A distinct Raman characteristic peak appeared at that location.

[0032] Although the above embodiments describe the present invention, it should be understood that the proportions of reagent components in the present invention can be adjusted without departing from the spirit of the present invention. The present invention is also applicable to the testing of mercury ions and amatoxins in other fields, and these modifications are also within the scope of the present invention.

Claims

1. A multifunctional nanomaterial Ni-MoS2@Au for detecting trace amounts of toxic substances in mushrooms, characterized in that, The nanomaterial is made from molybdenum disulfide (a metal oxide), polyvinylpyrrolidone (a surfactant), polyvinyl alcohol (or polyethylene glycol), gold nanoparticles (noble metal nanoparticles), and ultrapure water (a solvent). The specific operation is carried out according to the following steps: Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 to 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1-1:

3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mmol / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, rapidly add 0.5-1.5 mL of sodium citrate with a concentration of 38.75 mmol / mL to the boiling solution. The gold nanoparticles generated are cooled to room temperature after 15 minutes and stored in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add a surfactant with a mass fraction of 2-2.5%, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Mix and sonicate in an ice bath for 30 minutes. Centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

2. A method for preparing Ni-MoS2@Au, a multifunctional nanomaterial for detecting trace amounts of toxic substances in mushrooms, characterized in that, Follow these steps: Preparation of molybdenum disulfide: a. Add ammonium molybdate and thiourea to ultrapure water at a mass ratio of 1:1 to 1:3 and stir until homogeneous to obtain a mixed solution; b. Add nickel sulfate to the mixed solution obtained in step a, place it in a reaction vessel at 220°C and react for 18 hours. After cooling, remove it from the reaction vessel to obtain nickel-doped molybdenum disulfide, wherein the mass ratio of nickel sulfate to ammonium molybdate is 1:1-1:

3. Preparation of Ni-MoS2@Au nanomaterials: c. The nickel-doped molybdenum disulfide obtained in step b is washed three times by centrifugation with ultrapure water and ethanol, and then dried under vacuum at 60°C for 6 hours to obtain a blue-black powder. d. Mix 1 mL of tetrachloroauric acid with a concentration of 29.43 mmol / mL and 99 mL of ultrapure water and heat to boiling. Under vigorous stirring, rapidly add 0.5-1.5 mL of sodium citrate with a concentration of 38.75 mmol / mL to the boiling solution. The generated gold nanoparticles are cooled to room temperature after 15 minutes and stored in the dark. e. Add the blue-black powder obtained in step c to ultrapure water and sonicate for 10 minutes. Then centrifuge and wash once. Redisperse the precipitate in 40 mL of ultrapure water. Add a surfactant with a mass fraction of 2-2.5%, sonicate in an ice bath for 40 minutes, centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain a mixture. Then, take 5 mL of the mixture and add it to 40 mL of gold nanoparticle solution. Mix and sonicate in an ice bath for 30 minutes. Centrifuge and wash twice, and redisperse the precipitate in 10 mL of ultrapure water to obtain the nanomaterial Ni-MoS2@Au.

3. The multifunctional nanomaterial Ni-MoS2@Au for detecting trace amounts of toxic substances in mushrooms according to claim 1, characterized in that, The trace toxic substance in the mushrooms mentioned is the heavy metal ion Hg. 2+ And the biotoxins α-amanita and β-amanita.

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