Nanoparticles for raman detection, methods of making and using the same

Abstract

The application discloses a kind of nanoparticles for Raman detection, its preparation method and application, 1,4-diphenyl butadiyne is prepared into 1,4-diphenyl butadiyne-polystyrene composite nanoparticles by polymerization method;The obtained nanoparticles can obtain significantly enhanced Raman signal under the condition that metal sensitization is not needed through the cumulative effect of high-density chemical bond;The nanoparticle size is uniform, the morphology is regular, retains the characteristic Raman fingerprint peak of 1,4-diphenyl butadiyne at 1600 cm⁻¹, and the signal intensity is significantly better than monomer molecule. By modifying antibody or aptamer on the surface of the nanoparticle, specific capture and Raman detection of biological markers such as bacteria and protein can be realized, providing a new type of Raman probe sensitive, stable and without metal substrate for biomedical detection.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials, and in particular to a nanoparticle for Raman detection, its preparation method, and its application. Background Technology

[0002] Raman spectroscopy, as a non-destructive, label-free molecular fingerprinting technique, has shown broad application prospects in the fields of biomedical detection and disease diagnosis in recent years. Compared with fluorescence imaging, Raman spectroscopy has significant advantages such as narrow-band peaks, resistance to photobleaching, and resistance to photofading, making it particularly suitable for long-term dynamic imaging and analysis of biological samples. In the "Raman silent region" of cells (within the range of 1800-2800 cm⁻¹), endogenous biomolecules produce almost no interfering signals. Therefore, exogenous probes with characteristic Raman responses in this region can achieve high signal-to-noise ratio orthogonal imaging of biological samples.

[0003] 1,4-Diphenylbutyne is an aromatic compound with a conjugated diyne skeleton, containing two benzene rings linked by a C≡CC≡C conjugated chain. This molecule exhibits characteristic C≡C symmetric stretching vibrations in the Raman silent region (around 2220 cm⁻¹) and displays a distinct Raman fingerprint peak in the benzene ring region (around 1600 cm⁻¹), making it an ideal Raman signal molecule. Studies have shown that the Raman peak intensity of diarylbutyne probes can reach tens of times that of traditional acetylene-labeled molecules, while also possessing good photostability and low cytotoxicity, making them suitable for continuous Raman imaging of live cells.

[0004] However, the Raman signal intensity of 1,4-diphenylbutyne monomer is relatively limited. Currently, the commonly used strategy is to composite it with metal nanoparticles (such as Au and Ag) to utilize surface-enhanced Raman scattering (SERS) to improve detection sensitivity. However, the stability of the SERS probe's detection signal still depends to some extent on the plasmonic modulation of the metal substrate and the precise construction of the nanostructure, requiring a high degree of consistency in the detection environment. Therefore, it is necessary to improve existing technologies to overcome this limitation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a Raman detection nanoparticle, its preparation method and application, in order to address the shortcomings of the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing nanoparticles for Raman detection, comprising the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S2. Prepare a precursor solution, which includes an initiator solution and an emulsifier buffer containing an emulsifier and sodium bicarbonate; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Add the styrene solution of 1,4-diphenylbutadiene dropwise to the emulsifier buffer solution. After the addition is complete, continue stirring, purge with inert gas, raise the temperature, add the initiator solution, stir the reaction, and keep the reaction under argon protection throughout the process. S3-2. After the reaction is complete, the product is centrifuged, the precipitate is collected and dried to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, namely the nanoparticles for Raman detection.

[0007] Preferably, the initiator in the initiator solution is potassium persulfate or ammonium persulfate, and the emulsifier is sodium dodecyl sulfate.

[0008] Preferably, the method for preparing the nanoparticles for Raman detection includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene: Styrene is mixed with sodium hydroxide solution, shaken and washed, then washed with deionized water until neutral, and finally dried to obtain purified styrene. S1-2. Add 1,4-diphenylbutadiyne to purified styrene and sonicate until completely dissolved to obtain a styrene solution of 1,4-diphenylbutadiyne. S2. Preparation of precursor solution: Potassium persulfate was added to deionized water and heated until completely dissolved to obtain a potassium persulfate solution; sodium dodecyl sulfate and sodium bicarbonate were added to deionized water and stirred to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Under ice-water bath conditions and with stirring, a styrene solution of 1,4-diphenylbutadiene is added dropwise to an emulsion buffer. After the addition is complete, stirring is continued, argon gas is introduced and the temperature is raised. Then, potassium persulfate solution is added and the reaction is stirred. Argon gas is continuously introduced for protection throughout the reaction. S3-2. After the reaction is complete, cool the product, centrifuge it, collect the precipitate, wash it with deionized water and dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, namely the nanoparticles for Raman detection.

[0009] Preferably, the method for preparing the nanoparticles for Raman detection includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene: Mix styrene with an equal volume of sodium hydroxide solution with a mass concentration of 2-10% and shake and wash 2-5 times. Then wash with deionized water until neutral. Finally, dry with anhydrous sodium sulfate for 12-48 hours to obtain purified styrene. S1-2. Take 2.5-10 mg of 1,4-diphenylbutyne and add it to 2.5-10 g of purified styrene. Sonicate for 5-30 minutes until completely dissolved to obtain a clear and transparent solution, which is the styrene solution of 1,4-diphenylbutyne. S2. Preparation of precursor solution: Add 0.025-0.1g of potassium persulfate to 2.5-10mL of deionized water and heat at 40-60℃ until completely dissolved to obtain a potassium persulfate solution; add 0.25-1g of sodium dodecyl sulfate and 0.025-0.1g of sodium bicarbonate to 15-60mL of deionized water and stir at room temperature until completely transparent to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Under ice-water bath conditions and with stirring, add the styrene solution of 1,4-diphenylbutadiene dropwise to the emulsion buffer. After the addition is complete, continue stirring for 0.5-2 hours. After purging with argon gas for 15-60 minutes, raise the temperature to 60-80℃ and maintain it for 5-20 minutes. Then add potassium persulfate solution and stir the reaction at 60-80℃ for 6-24 hours. The reaction is protected by argon gas throughout. S3-2. After the reaction is complete, allow the mixture to cool naturally to room temperature. Centrifuge the product at 5000-20000 rpm for 5-30 minutes. Collect the precipitate, wash it with deionized water, and then dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, which are the nanoparticles used for Raman detection.

[0010] Preferably, the method for preparing the nanoparticles for Raman detection includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene: Styrene was mixed with an equal volume of 5% sodium hydroxide solution and washed three times by shaking. Then it was washed with deionized water until neutral and finally dried with anhydrous sodium sulfate for 24 hours to obtain purified styrene. S1-2. Take 5 mg of 1,4-diphenylbutyne and add it to 5 g of purified styrene. Sonicate for 15 minutes until completely dissolved to obtain a clear and transparent solution, which is the styrene solution of 1,4-diphenylbutyne. S2. Preparation of precursor solution: Add 0.05 g of potassium persulfate to 5 mL of deionized water and heat at 50 °C until completely dissolved to obtain a potassium persulfate solution; add 0.5 g of sodium dodecyl sulfate and 0.05 g of sodium bicarbonate to 30 mL of deionized water and stir at room temperature until completely transparent to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Under ice-water bath conditions and with stirring, a styrene solution of 1,4-diphenylbutadiene was added dropwise to an emulsion buffer. After the addition was complete, stirring was continued for 1 hour. Argon gas was passed through for 30 minutes, and the temperature was raised to 70°C and maintained for 10 minutes. Then, potassium persulfate solution was added, and the reaction was stirred at 70°C for 12 hours. Argon gas was continuously passed through the reaction throughout the process. S3-2. After the reaction is complete, allow the mixture to cool naturally to room temperature. Centrifuge the product at 10,000 rpm for 15 minutes. Collect the precipitate, wash it with deionized water, and then dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, which are the nanoparticles used for Raman detection.

[0011] The present invention also provides nanoparticles prepared by the method described above.

[0012] The present invention also provides an application of the nanoparticles described above in Raman detection.

[0013] The present invention also provides an application of the nanoparticles described above in Raman imaging.

[0014] Preferably, the nanoparticles are used for continuous Raman imaging of living cells.

[0015] The present invention also provides the application of the nanoparticles as described in claim 6 in the preparation of Raman probes.

[0016] The beneficial effects of this invention are: This invention provides nanoparticles for Raman detection, their preparation method, and applications. The invention prepares 1,4-diphenylbutyne-polystyrene composite nanoparticles via polymerization. The resulting nanoparticles, through the cumulative effect of high-density chemical bonds, achieve significantly enhanced Raman signals without the need for metal sensitization. These nanoparticles are uniform in size and morphology, retaining the characteristic Raman fingerprint peak of 1,4-diphenylbutyne at 1600 cm⁻¹, and exhibiting significantly stronger signal intensity than the monomer molecules. By modifying the surface of these nanoparticles with antibodies or aptamers, specific capture and Raman detection of biomarkers such as bacteria and proteins can be achieved, providing a sensitive, stable, and metal-substrate-free novel Raman probe for biomedical detection. Attached Figure Description

[0017] Figure 1 Transmission electron microscopy image of 1,4-diphenylbutadiyne-polystyrene nanoparticles prepared in Example 1; Figure 2 Raman spectra of 1,4-diphenylbutyne-polystyrene nanoparticles prepared in Example 1. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0019] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0020] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0021] Example 1 A nanoparticle for Raman detection, the preparation method of which includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene to remove polymerization inhibitor: Mix styrene with an equal volume of 5% sodium hydroxide solution, shake and wash 3 times, then wash with deionized water until neutral, and finally dry with anhydrous sodium sulfate for 24 hours to obtain purified styrene. S1-2. Take 5 mg of 1,4-diphenylbutyne and add it to 5 g of purified styrene. Sonicate for 15 minutes until completely dissolved to obtain a clear and transparent solution, which is the styrene solution of 1,4-diphenylbutyne. S2. Preparation of precursor solution: Add 0.05 g of potassium persulfate to 5 mL of deionized water and heat at 50 °C until completely dissolved to obtain a potassium persulfate solution; add 0.5 g of sodium dodecyl sulfate and 0.05 g of sodium bicarbonate to 30 mL of deionized water and stir at room temperature until completely transparent to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Transfer the emulsifier buffer to a 100 ml three-necked flask and stir at high speed (1000 rpm) under ice-water bath conditions. Add a styrene solution of 1,4-diphenylbutadiene dropwise to the three-necked flask. After the addition is complete, continue stirring (1000 rpm) for 1 hour. Then, transfer the three-necked flask to an oil bath, install a condenser, and purge with argon gas for 30 minutes. Then, raise the temperature to 70°C and maintain it for 10 minutes. Then, quickly add potassium persulfate solution all at once and stir at low speed (300 rpm) at 70°C for 12 hours. The reaction is protected by argon gas throughout the entire process. S3-2. After the reaction is complete, allow the mixture to cool naturally to room temperature. Centrifuge the product at 10,000 rpm for 15 minutes, collect the precipitate, wash it with deionized water, and dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, which are the nanoparticles used for Raman detection. Disperse the 1,4-diphenylbutadiyne-polystyrene nanoparticles ultrasonically in water. Store the resulting dispersion at 4 ℃ in the dark for subsequent testing.

[0022] Figure 1 This is a transmission electron microscope (TEM) image of the 1,4-diphenylbutadiyne-polystyrene nanoparticles prepared in this example. As can be seen from the image, the nanoparticles are approximately 40 nm in size, exhibit a standard spherical shape, uniform morphology, and good monodispersity.

[0023] Figure 2 The image shows the Raman spectrum of the 1,4-diphenylbutadiene-polystyrene nanoparticles prepared in this example. As can be seen from the image, the nanoparticles exhibit a strong Raman characteristic peak at 1600 cm⁻¹.

[0024] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A method for preparing nanoparticles for Raman detection, characterized in that, Includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S2. Prepare a precursor solution, which includes an initiator solution and an emulsifier buffer containing an emulsifier and sodium bicarbonate; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Add the styrene solution of 1,4-diphenylbutadiene dropwise to the emulsifier buffer solution. After the addition is complete, continue stirring, purge with inert gas, raise the temperature, add the initiator solution, stir the reaction, and keep the reaction under argon protection throughout the process. S3-2. After the reaction is complete, the product is centrifuged, the precipitate is collected and dried to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, namely the nanoparticles for Raman detection.

2. The method for preparing Raman detection nanoparticles according to claim 1, characterized in that, The initiator in the initiator solution is potassium persulfate or ammonium persulfate, and the emulsifier is sodium dodecyl sulfate.

3. The method for preparing Raman detection nanoparticles according to claim 2, characterized in that, Includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene: Styrene is mixed with sodium hydroxide solution, shaken and washed, then washed with deionized water until neutral, and finally dried to obtain purified styrene. S1-2. Add 1,4-diphenylbutadiyne to purified styrene and sonicate until completely dissolved to obtain a styrene solution of 1,4-diphenylbutadiyne. S2. Preparation of precursor solution: Potassium persulfate was added to deionized water and heated until completely dissolved to obtain a potassium persulfate solution; sodium dodecyl sulfate and sodium bicarbonate were added to deionized water and stirred to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Under ice-water bath conditions and with stirring, a styrene solution of 1,4-diphenylbutadiene is added dropwise to an emulsifier buffer. After the addition is complete, stirring is continued, argon gas is introduced and the temperature is raised. Then, potassium persulfate solution is added and the reaction is stirred. Argon gas is continuously introduced for protection throughout the reaction. S3-2. After the reaction is complete, cool the product, centrifuge it, collect the precipitate, wash it with deionized water and dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, namely the nanoparticles for Raman detection.

4. The method for preparing Raman detection nanoparticles according to claim 3, characterized in that, Includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene: Mix styrene with an equal volume of sodium hydroxide solution with a mass concentration of 2-10% and shake and wash 2-5 times. Then wash with deionized water until neutral. Finally, dry with anhydrous sodium sulfate for 12-48 hours to obtain purified styrene. S1-2. Take 2.5-10 mg of 1,4-diphenylbutyne and add it to 2.5-10 g of purified styrene. Sonicate for 5-30 minutes until completely dissolved to obtain a clear and transparent solution, which is the styrene solution of 1,4-diphenylbutyne. S2. Preparation of precursor solution: Add 0.025-0.1g of potassium persulfate to 2.5-10mL of deionized water and heat at 40-60℃ until completely dissolved to obtain a potassium persulfate solution; add 0.25-1g of sodium dodecyl sulfate and 0.025-0.1g of sodium bicarbonate to 15-60mL of deionized water and stir at room temperature until completely transparent to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Under ice-water bath conditions and with stirring, add the styrene solution of 1,4-diphenylbutadiene dropwise to the emulsion buffer. After the addition is complete, continue stirring for 0.5-2 hours. After purging with argon gas for 15-60 minutes, raise the temperature to 60-80℃ and maintain it for 5-20 minutes. Then add potassium persulfate solution and stir the reaction at 60-80℃ for 6-24 hours. The reaction is protected by argon gas throughout. S3-2. After the reaction is complete, allow the mixture to cool naturally to room temperature. Centrifuge the product at 5000-20000 rpm for 5-30 minutes. Collect the precipitate, wash it with deionized water, and then dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, which are the nanoparticles used for Raman detection.

5. The method for preparing Raman detection nanoparticles according to claim 4, characterized in that, Includes the following steps: S1. Preparation of a styrene solution of 1,4-diphenylbutadiene: S1-1. Purification of styrene: Styrene was mixed with an equal volume of 5% sodium hydroxide solution and washed three times by shaking. Then it was washed with deionized water until neutral and finally dried with anhydrous sodium sulfate for 24 hours to obtain purified styrene. S1-2. Take 5 mg of 1,4-diphenylbutadiene and add it to 5 g of purified styrene. Sonicate for 15 minutes until completely dissolved to obtain a clear and transparent solution, which is the styrene solution of 1,4-diphenylbutadiene. S2. Preparation of precursor solution: Add 0.05 g of potassium persulfate to 5 mL of deionized water and heat at 50 °C until completely dissolved to obtain a potassium persulfate solution; add 0.5 g of sodium dodecyl sulfate and 0.05 g of sodium bicarbonate to 30 mL of deionized water and stir at room temperature until completely transparent to obtain an emulsifier buffer solution; S3. Preparation of nanoparticles by emulsion polymerization: S3-1. Under ice-water bath conditions and with stirring, a styrene solution of 1,4-diphenylbutadiene was added dropwise to an emulsion buffer. After the addition was complete, stirring was continued for 1 hour. Argon gas was passed through for 30 minutes, and the temperature was raised to 70°C and maintained for 10 minutes. Then, potassium persulfate solution was added, and the reaction was stirred at 70°C for 12 hours. Argon gas was continuously passed through the reaction throughout the process. S3-2. After the reaction is complete, allow the mixture to cool naturally to room temperature. Centrifuge the product at 10,000 rpm for 15 minutes. Collect the precipitate, wash it with deionized water, and then dry it to obtain 1,4-diphenylbutadiyne-polystyrene nanoparticles, which are the nanoparticles used for Raman detection.

6. A nanoparticle prepared by the method according to any one of claims 1-5.

7. An application of the nanoparticles as described in claim 6 in Raman detection.

8. An application of the nanoparticles as described in claim 6 in Raman imaging.

9. The application according to claim 8, characterized in that, The nanoparticles are used for continuous Raman imaging of live cells.

10. The application of the nanoparticles as described in claim 6 in the preparation of Raman probes.

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