Paper-based nanoparticle synthesis methods and paper-based nanoparticle devices and applications

Abstract

A paper-based gold nanoparticle synthesis method, paper-based gold nanoparticle device and application, by utilizing the three-dimensional network structure of paper fibers to disperse and fix gold nanoparticles AuNPs, can prevent the aggregation of particles, make them exhibit better anti-interference ability in complex environment, and maintain their high catalytic activity, characterized by the following steps: step 1, cleaning and activating the paper to keep and strengthen the three-dimensional network fiber structure of the paper itself; step 2, soaking the cleaned and activated paper in a solution of gold precursor chloroauric acid, so that the chloroauric acid molecules are fully adsorbed into the three-dimensional network fiber structure of the paper itself; step 3, reducing the chloroauric acid molecules in the three-dimensional network fiber structure to gold nanoparticles by using a reducing agent to realize in-situ synthesis of AuNPs; step 4, drying and refrigerated storage of the paper with in-situ synthesized AuNPs.

Description

Technical Field

[0001] This invention relates to the fields of nanomaterials and biocatalysis, and in particular to a method for synthesizing paper-based nanoparticles, as well as paper-based nanoparticle devices and applications. By utilizing the three-dimensional network structure of paper fibers to disperse and fix gold nanoparticles (AuNPs), particle aggregation can be prevented, enabling them to exhibit better anti-interference ability in complex environments and maintain their high-efficiency catalytic activity. Background Technology

[0002] Gold nanoparticles (AuNPs), as important nanomaterials, have been widely used in catalysis, biosensing, medical imaging, and drug delivery due to their excellent physical and chemical properties. Particularly in catalysis, AuNPs exhibit unique enzyme-like catalytic properties, such as catalase-like activity, making them ideal candidate materials for environmental pollutant detection and biocatalysis research.

[0003] However, the catalytic performance of AuNPs largely depends on their surface activity and dispersibility. When AuNPs are at the nanoscale, their large surface area provides more active sites, resulting in higher catalytic efficiency. However, due to the strong van der Waals forces and surface energy between nanoparticles, they tend to aggregate in solution, forming larger particles or clusters. This aggregation significantly reduces the surface area of ​​AuNPs, thus weakening their catalytic performance. Furthermore, in practical applications, AuNPs are easily affected by solution pH, ionic strength, and other chemical substances, further impacting their catalytic efficacy and stability.

[0004] To overcome the aforementioned problems, researchers have proposed various methods to stabilize AuNPs and improve their catalytic performance. For example, modifying the surface of AuNPs with organic molecules or polymers can prevent their aggregation to some extent. However, these methods often suffer from drawbacks such as complex processes, high costs, and potential impact on the catalytic activity of AuNPs. Therefore, finding a simple, effective, and low-cost method to stabilize AuNPs and maintain their excellent catalytic performance has become a current research hotspot.

[0005] This invention addresses the problem of catalytic performance degradation caused by the instability of gold nanoparticles by proposing a novel strategy for in-situ synthesis of AuNPs on a porous fiber paper substrate. The natural porous structure of paper fibers effectively disperses and immobilizes AuNPs, preventing particle aggregation and maintaining their high catalytic activity. Furthermore, the three-dimensional network structure of the paper fibers provides additional protection for the AuNPs, enabling them to exhibit better resistance to interference in complex environments. This innovative design not only simplifies the preparation process of AuNPs and reduces costs but also significantly enhances their practical application potential in fields such as biocatalysis and environmental monitoring. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a method for synthesizing paper-based nanoparticles, as well as paper-based nanoparticle devices and applications. By utilizing the three-dimensional network structure of paper fibers to disperse and immobilize gold nanoparticles (AuNPs), particle aggregation can be prevented, enabling them to exhibit better anti-interference capabilities in complex environments and maintain their highly efficient catalytic activity.

[0007] The technical solution of the present invention is as follows:

[0008] A method for synthesizing paper-based nanoparticles, characterized by comprising the following steps:

[0009] Step 1: Clean and activate the paper to maintain and strengthen its three-dimensional network fiber structure.

[0010] Step 2: Immerse the cleaned and activated paper in a solution of chloroauric acid, the gold precursor, so that the chloroauric acid molecules can be fully adsorbed into the three-dimensional network fiber structure of the paper itself.

[0011] Step 3: A reducing agent is used to reduce chloroauric acid molecules in the three-dimensional network fiber structure into gold nanoparticles to achieve in-situ synthesis of AuNPs;

[0012] Step 4: After drying the paper from which AuNPs were synthesized in situ, store it under cold conditions.

[0013] The cleaning process in step 1 includes removing impurities and / or contaminants from the paper surface using deionized water and / or ethanol solutions.

[0014] The activation process in step 1 involves activating the paper fibers by ultraviolet light irradiation to enhance the interaction between the paper fibers and the gold precursor, thereby improving the adsorption capacity of the paper fibers for the gold precursor.

[0015] Step 2 involves using a rotary oscillation device to treat the chloroauric acid solution by rotation and oscillation, followed by rinsing with deionized water and / or ethanol solution to remove chloroauric acid molecules that have not been adsorbed by the paper fibers.

[0016] Step 3 includes using trisodium citrate as a reducing agent and using a rotating oscillation device to rotate and oscillate the trisodium citrate solution soaking the paper under heating conditions, followed by rinsing with deionized water and / or ethanol solution.

[0017] The concentration of the chloroauric acid solution is 10 nanomolar.

[0018] The concentration of the trisodium citrate solution is 1 wt%.

[0019] A paper-based nanoparticle device, made using the above-mentioned paper-based nanoparticle synthesis method, is characterized by including cutting paper from which AuNPs are synthesized in situ and stored under cold conditions into devices of different shapes or sizes.

[0020] An application of a paper-based nanoparticle device is characterized by applying the paper-based nanoparticle device to environmental pollutant detection, medical diagnosis, and / or industrial catalysis.

[0021] The technical effects of this invention are as follows: This invention provides a method for synthesizing paper-based nanoparticles, as well as paper-based nanoparticle devices and applications. It solves the problem of AuNPs easily agglomerating in solution, leading to a decrease in catalytic performance, and enhances their stability and anti-interference ability, thereby improving their catalase-like catalytic performance. This invention utilizes the natural porous structure of paper fibers as a carrier, employing a simple and efficient in-situ synthesis technique to stably load AuNPs onto a paper substrate, thus achieving uniform dispersion and long-term stability of the nanoparticles.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. Simple and cost-effective process: This invention simplifies the preparation of AuNPs by optimizing the synthesis process. The entire synthesis process does not require complex surface modification or other protective steps, and only utilizes the natural porous structure of paper fibers to achieve stable loading and dispersion of nanoparticles, significantly reducing production costs.

[0024] 2. Significantly Enhanced Stability: By loading AuNPs onto a paper substrate, the nanoparticles are effectively protected by a physical barrier, preventing aggregation and growth between particles, thus maintaining their unique nanoscale properties. Simultaneously, the network structure of the paper fibers provides AuNPs with a larger specific surface area, enabling them to exhibit higher activity during catalysis, particularly a significant enhancement of catalase-like catalytic activity.

[0025] 3. Process Repeatability and Scalability: This method is simple and easy to implement, with high process repeatability, making it suitable for large-scale production. Furthermore, the selection of filter paper materials and processing conditions can be adjusted according to specific applications, thus extending to the preparation of other types of metal nanoparticles.

[0026] 4. Strong anti-interference ability: Unlike traditional free AuNPs, AuNPs loaded on paper substrates exhibit stronger resistance to common environmental factors such as pH fluctuations and ion interference, making them more reliable and stable in the detection of complex samples.

[0027] 5. Broad application potential: The technical solution of this invention is not only applicable to the preparation of gold nanoparticles, but can also be extended to the synthesis of other metal nanoparticles, such as silver, copper, and platinum, thereby playing a role in a wider range of fields, including but not limited to catalyst preparation, sensor development, and medical diagnostics.

[0028] In summary, this invention proposes a method for synthesizing AuNPs based on paper fiber structure. By utilizing the natural advantages of the paper substrate, it achieves efficient stabilization of gold nanoparticles and enhanced catalytic performance, which has significant scientific research value and promising industrial application prospects. Attached Figure Description

[0029] Figure 1 This is a schematic flowchart illustrating the method for synthesizing paper-based nanoparticles according to the present invention. Figure 1 The labels in the text are explained as follows: 1-Filter paper; 2-Chloroauric acid solution; 3-Pretreated filter paper; 4-Trisodium citrate solution; 5-Gold nanoparticles based on paper fiber structure.

[0030] Figure 2 This is a real-life image of AuNPs based on paper fiber structures.

[0031] Figure 3 This is a scanning electron microscope image of AuNPs based on paper fiber structures. Detailed Implementation

[0032] The following is in conjunction with the attached diagram ( Figures 1-3 The present invention will be described in conjunction with the embodiments.

[0033] Figure 1 This is a schematic flowchart illustrating the method for synthesizing paper-based nanoparticles according to the present invention. Figure 2 This is a real-life image of AuNPs based on paper fiber structures. Figure 3 Scanning electron microscope (SEM) images of AuNPs based on paper fiber structures. (Reference) Figures 1 to 3 As shown, a method for synthesizing paper-based gold nanoparticles includes the following steps: Step 1, cleaning and activating the paper to maintain and strengthen its three-dimensional network fiber structure; Step 2, immersing the cleaned and activated paper in a solution of chloroauric acid, a gold precursor, to allow chloroauric acid molecules to be fully adsorbed into the three-dimensional network fiber structure of the paper; Step 3, using a reducing agent to reduce the chloroauric acid molecules in the three-dimensional network fiber structure into gold nanoparticles to achieve in-situ synthesis of AuNPs; Step 4, drying the paper from which AuNPs have been synthesized in situ and storing it under cold conditions.

[0034] The cleaning process in Step 1 includes removing impurities and / or contaminants from the paper surface using deionized water and / or ethanol solution. The activation process in Step 1 includes activating the paper fibers by ultraviolet light irradiation to enhance the interaction between the paper fibers and the gold precursor, thereby improving the adsorption capacity of the paper fibers for the gold precursor.

[0035] Step 2 involves using a rotary oscillation device to treat the chloroauric acid solution by rotation and agitation, followed by rinsing with deionized water and / or ethanol solution to remove chloroauric acid molecules not adsorbed by the paper fibers. Step 3 involves using trisodium citrate as a reducing agent and using a rotary oscillation device to treat the trisodium citrate solution soaking the paper by rotation and agitation under heating conditions, followed by rinsing with deionized water and / or ethanol solution.

[0036] The concentration of the chloroauric acid solution is 10 nanomolar. The concentration of the trisodium citrate solution is 1 wt%.

[0037] A paper-based nanoparticle device is fabricated using the aforementioned paper-based nanoparticle synthesis method, which includes cutting paper from which AuNPs are synthesized in situ and stored under refrigeration into devices of different shapes or sizes.

[0038] An application of a paper-based nanoparticle device includes applying the aforementioned paper-based nanoparticle device to environmental pollutant detection, medical diagnosis, and / or industrial catalysis.

[0039] This invention relates to the fields of nanomaterials and biocatalysis, specifically to a novel method for in-situ synthesis of gold nanoparticles (AuNPs) on a porous fiber paper substrate, and the applications of the thus prepared AuNPs in biocatalysis and environmental monitoring. Gold nanoparticles, due to their unique physicochemical properties, have broad application prospects in catalysis, biosensing, and medical diagnostics. However, the tendency of gold nanoparticles to aggregate in solution leads to unstable catalytic performance, limiting their effectiveness in practical applications.

[0040] This invention utilizes the natural porous structure of paper fibers to directly synthesize and load AuNPs onto a paper substrate, effectively avoiding particle aggregation problems. The three-dimensional network structure of paper fibers not only stably supports nanoparticles but also provides additional protection, enabling AuNPs to exhibit superior anti-interference ability and stability in complex environments. The AuNPs prepared by this invention exhibit excellent catalase-like catalytic performance, making them particularly suitable for practical applications in environmental pollutant detection, medical diagnostics, and industrial catalysis.

[0041] This invention provides an innovative method for synthesizing gold nanoparticles (AuNPs) based on a porous fiber paper substrate. The aim is to address the problem of AuNPs' tendency to aggregate in solution, leading to a decline in catalytic performance, and to enhance their stability and anti-interference ability, thereby improving their catalase-like catalytic performance. This method utilizes the natural porous structure of paper fibers as a carrier, employing a simple and efficient in-situ synthesis technique to stably load AuNPs onto a paper substrate, thus achieving uniform dispersion and long-term stability of the nanoparticles.

[0042] Specifically, the technical solution of the present invention includes the following steps:

[0043] 1. Pretreatment of the paper substrate: 8 mm diameter filter paper was selected as the substrate material and pretreated. First, the paper underwent surface cleaning and activation. Cleaning was performed using deionized water and ethanol solution to remove any impurities and contaminants that might be present on the surface. Next, the paper fibers were activated by ultraviolet light irradiation to enhance their interaction with the gold precursor (chloroauric acid), thereby improving the adsorption capacity of the gold precursor. This pretreatment step not only ensured the uniformity of subsequent synthesis but also enhanced the adhesion stability of AuNPs on the paper substrate.

[0044] 2. In-situ Synthesis of Gold Nanoparticles - Step 1: Pretreated filter paper was immersed in a chloroauric acid solution (0.5 mL, 10 nanomolar concentration) and then shaken at 90 rad / s for 20 minutes on a rotary shaker. This step aims to ensure that chloroauric acid molecules are fully adsorbed into the pores of the filter paper, thus laying the foundation for subsequent nanoparticle synthesis. After shaking, the paper was rinsed twice with deionized water and ethanol solution, respectively, to remove unadsorbed chloroauric acid molecules and other impurities.

[0045] 3. In-situ Synthesis of Gold Nanoparticles - Step Two: AuNPs are synthesized in situ on the filter paper treated in the previous step. The specific steps include immersing the rinsed filter paper in a filtered trisodium citrate solution (0.5 mL, 1% concentration), followed by rotation and shaking at 80°C for 30 minutes. During this process, trisodium citrate acts as a reducing agent, reducing chloroauric acid adsorbed in the pores of the filter paper to gold nanoparticles. The gold nanoparticles form directly on the paper fibers and adhere firmly to the paper substrate. Unlike traditional chemical reduction methods, this invention does not require the addition of additional surfactants or protective agents; it utilizes only the structural characteristics of the paper fibers to achieve stable dispersion of AuNPs. After shaking, the filter paper is rinsed twice with deionized water and ethanol solution respectively to remove excess chemicals.

[0046] 4. Post-processing and Application: The synthesized AuNPs-loaded filter paper is further stabilized through drying and refrigerated storage. After these processing steps, the filter paper exhibits excellent stability and catalytic performance, making it particularly suitable for applications such as environmental monitoring, biosensing, and industrial catalysis. Due to the flexibility and cutability of the paper substrate, these AuNPs-loaded filter papers can also be further processed into devices of different shapes or sizes according to specific application requirements.

[0047] This invention discloses a method for synthesizing AuNPs nanoparticles based on the porous structure of paper fibers and their catalytic applications with enhanced stability. Taking the catalytic reaction of hydrogen peroxide as an example, the method includes the following steps:

[0048] 1. At the same time, take another centrifuge tube and add the following to the tube in sequence: 80 μL of 10 mM 3,3′,5,5′-tetramethylbenzidine (TMB) solution, 100 μL of 0.1% hydrogen peroxide (H2O2), and incubate for 10 minutes.

[0049] 2. Then add a piece of the synthesized paper-based AuNPs to step 1.

[0050] 3. The change in the solution from colorless to blue in step 2 demonstrates that the paper-based AuNPs have excellent stability and catalytic performance.

[0051] 4. Explanation of chemical reaction mechanisms:

[0052] Paper-based AuNPs can catalyze the oxidation of TMB to its oxidized form TMBox in the presence of H2O2, because AuNPs have peroxidase-like catalytic activity.

[0053] The specific mechanism can be explained in the following steps:

[0054] a. Surface active sites: AuNPs have highly active uncoordinated gold atoms on their surface, which can adsorb and activate hydrogen peroxide molecules. The nanoscale size and high specific surface area of ​​AuNPs make their surface active sites more abundant, thereby enhancing catalytic efficiency.

[0055] b. Dissociation of H2O2: On the surface of AuNPs, H2O2 can dissociate into reactive oxygen species (such as hydroxyl radicals OH• and peroxyl radicals HO2•) through catalytic action on the AuNPs surface. These reactive oxygen species are strong oxidants and can further initiate oxidation reactions.

[0056] c. Oxidation of TMB: Under the influence of these reactive oxygen species, TMB molecules are oxidized into blue-tinged oxidation products called TMBox. Specifically, the amine group (–NH2) in the TMB molecule is oxidized to form an amine radical, which is then further oxidized to finally generate the blue-tinged oxidized TMBox.

[0057] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features.

[0058] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, and / or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A method for synthesizing paper-based nanoparticles, characterized in that, Includes the following steps: Step 1: Clean and activate the paper to maintain and strengthen its three-dimensional network fiber structure. Step 2: Immerse the cleaned and activated paper in a solution of chloroauric acid, the gold precursor, so that the chloroauric acid molecules are fully adsorbed into the three-dimensional network fiber structure of the paper itself. Step 3: A reducing agent is used to reduce chloroauric acid molecules in the three-dimensional network fiber structure into gold nanoparticles to achieve in-situ synthesis of AuNPs; Step 4: After drying the paper from which AuNPs were synthesized in situ, store it under cold storage. The activation process in step 1 includes activating the paper fibers by ultraviolet light irradiation to enhance the interaction between the paper fibers and the gold precursor, thereby improving the adsorption capacity of the paper fibers for the gold precursor. Step 3 includes using trisodium citrate as a reducing agent and using a rotating oscillation device to rotate and oscillate the trisodium citrate solution soaking the paper under heating conditions, followed by rinsing with deionized water and / or ethanol solution.

2. The method for synthesizing paper-based nanoparticles according to claim 1, characterized in that, The cleaning process in step 1 includes removing impurities and / or contaminants from the paper surface using deionized water and / or ethanol solutions.

3. The method for synthesizing paper-based nanoparticles according to claim 1, characterized in that, Step 2 involves using a rotary oscillation device to treat the chloroauric acid solution by rotation and oscillation, followed by rinsing with deionized water and / or ethanol solution to remove chloroauric acid molecules that have not been adsorbed by the paper fibers.

4. The method for synthesizing paper-based nanoparticles according to claim 1, characterized in that, The concentration of the chloroauric acid solution is 10 nanomolar.

5. The method for synthesizing paper-based nanoparticles according to claim 1, characterized in that, The concentration of the trisodium citrate solution is 1 wt%.

6. A paper-based nanoparticle device, manufactured using the paper-based nanoparticle synthesis method described in any one of claims 1-5, characterized in that, This includes cutting refrigerated paper containing in-situ synthesized AuNPs into devices of different shapes or sizes.

7. An application of a paper-based nanoparticle device, characterized in that, This includes applying the paper-based nanoparticle device described in claim 6 to environmental pollutant detection, medical diagnosis, and / or industrial catalysis.

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