Method for in-situ synthesis of nano material by using PDMS microneedle

Abstract

The invention relates to the field of microneedle technology and nano material preparation, and particularly discloses a method for in-situ synthesis of a nano material on a PDMS microneedle. The method comprises the following steps: dropwise adding an ascorbic acid solution on the surface of the PDMS microneedle, then adding a silver nitrate solution, mixing and reacting the ascorbic acid solution and the silver nitrate solution to form a silver nano-material, and washing the microneedle to obtain the PDMS microneedle with the surface modified with nano-particles. Preferably, the concentration of ascorbic acid is 125 mM, the concentration of silver nitrate is 100 mM, and the reaction time is about 10 minutes. The prepared microneedle can be used as a flexible surface enhanced Raman scattering (SERS) substrate and has high sensitivity and uniformity, and the preparation method is simple and convenient to operate, mild and free of complex equipment. The invention provides a simple, convenient and efficient preparation method of a microneedle nano material, and a new technical approach is provided for application of the microneedle in the fields of biosensing and nano detection.

Description

Technical Field

[0001] This invention relates to the field of microneedle technology, and more specifically to a method for in-situ synthesis of nanomaterials on PDMS microneedles. Background Technology

[0002] Microneedles (MNs) are tiny needle-like structures with lengths ranging from 100 to 1000 µm. As an emerging drug delivery technology, they have attracted widespread attention in recent years. The concept of microneedles was first proposed in the 1970s, but their application remained largely theoretical due to limitations in microfabrication technology at the time. With the development of microfabrication technology in the 1990s, microneedle fabrication gradually became a reality, and their length, size, and shape can be individually designed according to treatment needs. Over the past two decades, microneedle technology has developed rapidly, giving rise to various types, including solid microneedles, hollow microneedles, coated microneedles, soluble microneedles, and hydrogel microneedles.

[0003] However, existing microneedle technology is mainly used for drug delivery or active substance transport, and there is still a lack of methods for directly synthesizing nanomaterials in situ on the surface of microneedles. This leads to the traditional microneedle nanomaterial composite process requiring the preparation of nanoparticles first, and then loading them onto the microneedle surface, which suffers from problems such as complex steps, poor uniformity, and low preparation efficiency. Therefore, developing a simple method to generate nanomaterials in situ on the surface of microneedles has significant technical importance and application potential. Summary of the Invention

[0004] To address the problems of complex loading methods and poor uniformity of nanomaterials on microneedle surfaces in existing technologies, this invention provides a method for in-situ synthesis of nanomaterials on PDMS microneedles.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention discloses a method for in-situ synthesis of nanomaterials on PDMS microneedles, comprising the following steps: (1) Add 10 μL of 125 mM ascorbic acid solution to the surface of PDMS microneedles to fully wet the surface of the microneedles; (2) Then add 10 μL of 100 mM silver nitrate solution to mix the solution evenly. After the reaction is complete, silver nanomaterials are formed on the surface of the microneedles. (3) After the reaction is complete, the microneedles are washed to obtain PDMS microneedles with silver nanomaterials on the surface.

[0006] Preferably, the reaction time is 10 minutes.

[0007] Preferably, the method for preparing the PDMS microneedles is as follows: using SYLGARD... TMIn the 184 Silicone Elastomer Kit, components A and B are mixed evenly in a mass ratio of 10:1 and refrigerated until the bubbles disappear to obtain PDMS. The PDMS is then added to a PDMS microneedle negative mold, and vacuum is applied to remove excess solution. After drying / curing, the PDMS microneedles are finally demolded to obtain the PDMS microneedles.

[0008] The present invention has the following beneficial effects: ① Silver nanomaterials can be synthesized in situ on the surface of flexible PDMS microneedles, simplifying the preparation steps; ② The prepared microneedles can be used as flexible surface-enhanced Raman scattering (SERS) substrates, with high sensitivity and uniformity; ③ The method is simple and gentle to operate, requires no complicated equipment, and is easy to promote and apply. Attached Figure Description

[0009] Figure 1 This is a photograph of the in-situ synthesis of silver nanomaterials on PDMS microneedles. Figure 2 Field emission scanning electron microscope image of silver nanomaterials synthesized in situ on PDMS microneedles; Figure 3 Surface-enhanced Raman spectra of silver nanomaterials synthesized in situ on PDMS microneedles prepared with different concentrations of ascorbic acid and silver nitrate; Figure 4 The images show the surface-enhanced Raman spectra of silver nanomaterials synthesized in situ on PDMS microneedles with different concentrations of 4-MBA. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] Unless otherwise specified, the technical means used in the implementation examples are conventional means well known to those skilled in the art.

[0012] This invention discloses a method for in-situ synthesis of nanomaterials on PDMS microneedles, comprising the following steps: (1) Microneedle preparation Mix components A and B of the SYLGARD™ 184 Silicone Elastomer Kit at a mass ratio of 10:1 until homogeneous, and refrigerate until the bubbles disappear to obtain PDMS (polydimethylsiloxane); pour the PDMS into a microneedle mold, remove excess solution by vacuuming, and demold after drying / curing to obtain PDMS microneedles.

[0013] (2) In-situ synthesis of silver nanomaterials 10 μL of 125 mM ascorbic acid solution was dropped onto the surface of PDMS microneedles, followed by 10 μL of 100 mM silver nitrate solution. After mixing thoroughly and reacting for about 10 minutes, the mixture was washed to obtain PDMS microneedles with silver nanoparticles on the surface (see...). Figure 1 and Figure 2 ). Surface-enhanced Raman spectroscopy (SERS) tests showed that the nanoparticles on the microneedle surface exhibited a significant Raman enhancement effect (see...). Figure 3 This indicates that it has high sensitivity.

[0014] (3) 4-MBA test Different concentrations of 4-MBA (4-mercaptobenzoic acid, 10 μM, 0.1 μM, 1 nM) were coated onto the silver nanomaterial-modified microneedles described above. After reacting for 30 minutes, the coating was washed off, and Raman signal testing was performed. The results showed that even at a low concentration (1 nM), Raman signals could still be detected on the surface of the microneedles, verifying their high sensitivity performance (see...). Figure 4 ).

[0015] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for in-situ synthesis of nanomaterials on PDMS microneedles, characterized by: 10 μL of 125 mM ascorbic acid solution was added to the PDMS microneedle, followed by 10 μL of 100 mM silver nitrate solution, mixed well, and after the reaction was completed, washing was performed, and in-situ synthesis of silver nanomaterials on the PDMS microneedle was completed.

2. The method of claim 1, wherein: The reaction time was 10 min.

3. The method of claim 1, wherein: The preparation method of the PDMS microneedle is as follows: uniformly mixing components A and B in Silicone Elastomer Kit in a mass ratio of 10:1, and refrigerating until bubbles disappear to obtain PDMS; and adding the PDMS into a PDMS microneedle negative mold, vacuumizing, and removing excess solution. TM 184 uniformly mixing components A and B in Silicone Elastomer Kit in a mass ratio of 10:1, and refrigerating until bubbles disappear to obtain PDMS; and adding the PDMS into a PDMS microneedle negative mold, vacuumizing, and removing excess solution. Drying / curing was performed, and finally, the PDMS microneedle was demolded.

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