A 4D printing-based solid phase extraction micro-column array chip and a construction method and application thereof

Abstract

This invention discloses a 4D-printed solid-phase extraction micropillar array chip, its construction method, and its applications, belonging to the field of separation and analysis detection technology. The micropillar array chip includes a microextraction device, which comprises magnetically responsive micropillars formed by multiple magnetic flowers connected in series. The construction method of the micropillar array chip includes the following steps: printing magnetic flowers; connecting multiple magnetic flowers in series to form magnetically responsive micropillars; combining the micropillars with a micropillar shell to obtain the microextraction device; and combining multiple microextraction devices with an array shell to obtain the micropillar array chip. This invention integrates 4D-printed magnetically responsive structures into microfluidic channels, introducing intelligence, dynamism, and real-time processing into the sample pretreatment process to achieve dynamic control of the solid-phase extraction process. It has advantages such as high efficiency, high accuracy, and high flexibility, and is suitable for solid-phase extraction and speciation analysis of metal elements.

Description

Technical Field

[0001] This invention relates to the field of solid-phase extraction micropillar array chip technology, specifically to a solid-phase extraction micropillar array chip based on 4D printing, its construction method, and its application. Background Technology

[0002] The analysis of metallic speciation is of great significance in fields such as environmental monitoring, materials science, and life sciences, because different speciations and states of existence of metals directly affect their properties and reactivity. However, accurately and efficiently analyzing the different speciations of metallic elements remains a challenging task. Traditional analytical methods often suffer from poor selectivity, cumbersome operations, and complex sample pretreatment when dealing with different metallic speciations. Solid-phase microextraction based on microcolumns can effectively improve enrichment efficiency, performing enrichment and separation within the column and reducing sample loss during the enrichment process. The microcolumn-based extraction process eliminates the need for multiple pipetting and sample transfers, reducing the risk of operational errors and making it particularly suitable for automated analytical workflows. Furthermore, integrating multiple microcolumns onto a chip to construct a microextraction chip platform enables high-throughput sample processing.

[0003] In recent years, 3D printing technology has made the design of solid-phase extraction microcolumns highly flexible and customizable. Researchers can precisely design the structure, shape, and channels of the column according to specific analytical needs to adapt to the properties of different analytes. This personalized design helps improve the selectivity and efficiency of analysis. However, traditional 3D printing technology is static in the time dimension and cannot adapt to the needs of material morphology changes.

[0004] To overcome the shortcomings of traditional 3D printing technology in solid-phase extraction, the introduction of 4D printing technology can provide a more innovative solution. 4D printing adds a time dimension to 3D printing, enabling materials to undergo morphological and property changes in response to external stimuli, bringing multiple advantages to the solid-phase extraction process. First, 4D printing technology allows for real-time material response, enabling dynamic adjustments to the solid-phase extraction process based on actual conditions. For example, temperature-sensitive materials can be designed to undergo morphological changes with temperature, thereby controlling the extraction process. Such real-time adjustments enhance the selectivity and efficiency of extraction. Second, 4D printing technology introduces greater controllability and precision to the solid-phase extraction process. By designing material structures with specific responsive characteristics, fine-tuning of key parameters such as extraction rate and carrier selection can be achieved. This controllability facilitates more precise operation during extraction, resulting in more reliable analytical results.

[0005] Therefore, this invention provides a method for constructing a solid-phase extraction micropillar array chip based on 4D printing, combining 3D printing technology, 4D printing technology, and a microfluidic system to build a solid-phase microextraction microfluidic chip platform. As an innovative tool, the microfluidic chip has the characteristic of precisely manipulating trace amounts of liquid, enabling minimal reagent consumption, high-throughput analysis, and rapid experimental processes. By integrating 4D-printed magnetically responsive structures into the microfluidic channels, dynamic control of the solid-phase extraction process can be achieved, thereby improving selectivity and extraction efficiency. Summary of the Invention

[0006] To address the shortcomings of the existing technologies, one of the objectives of this invention is to provide a solid-phase extraction micropillar array chip based on 4D printing. This invention provides a solid-phase extraction micropillar array chip that integrates 4D-printed magnetic responsive structures in a microfluidic channel, introducing intelligent, dynamic, and real-time capabilities into the sample pretreatment process to achieve dynamic control of the solid-phase extraction process. It has advantages such as high efficiency, high accuracy, and high flexibility, and can realize solid-phase extraction and speciation analysis of metal elements.

[0007] To achieve the above objectives, the specific technical solution of the present invention is as follows:

[0008] A solid-phase extraction micropillar array chip based on 4D printing, the solid-phase extraction micropillar array chip includes a microextraction device; the microextraction device includes magnetically responsive micropillars formed by multiple magnetic flowers connected in series; the raw material of the magnetic flowers includes a blend of PDMS / Fe3O4 / SiO2.

[0009] Preferably, the mass ratio of PDMS, Fe3O4, and SiO2 is 1:(0.5~3):(0.01~1).

[0010] More preferably, the mass ratio of PDMS, Fe3O4, and SiO2 is 1:2:0.02.

[0011] The above-mentioned method for constructing a solid-phase extraction micropillar array chip based on 4D printing includes the following steps:

[0012] (1) Preparation of magnetic flowers: PDMS / Fe3O4 / SiO2 blend was used to make magnetic flowers;

[0013] (2) Preparation of microextraction device: Multiple magnetic flowers are connected in series to form a microcolumn with magnetic response, and the microcolumn is combined with the shell of the microcolumn to obtain the microextraction device;

[0014] (3) Chip fabrication: Multiple microextraction devices are combined with an array shell to obtain a micropillar array chip.

[0015] Preferably, the magnetic flower is obtained by direct ink writing (DIW) printing; the micropillar shell and the array shell are both obtained by LCD (Liquid-crystal display) printing.

[0016] Preferably, the diameter of the magnetic flower is 0.2~20 mm and the thickness is 0.1~2 mm.

[0017] Preferably, the magnetic flower has ≥3 petals.

[0018] Preferably, the micropillar is formed by connecting multiple magnetic flowers in series through capillary tubes.

[0019] Preferably, in step (3), nine microextraction devices are combined with an array shell to obtain a micropillar array chip.

[0020] This invention utilizes a PDMS / Fe3O4 / SiO2 blend as a material with shape memory effect, enabling shape changes under magnetic field stimulation. Fe3O4 acts as a magnetic response source, imparting shape changes to the magnetic flowers in a magnetic field. PDMS, as an elastic and biocompatible material, is used to prepare printable inks. The incorporation of SiO2 promotes the uniform dispersion of Fe3O4 in PDMS, enhancing the mechanical strength of the magnetic flowers. The magnetic flowers constructed by layer-by-layer deposition of the PDMS / Fe3O4 / SiO2 blend under applied pressure exhibit shape memory behavior, deforming under magnetic field stimulation and recovering their initial shape by controlling the magnetic field. A similar phenomenon occurs when multiple magnetic flowers are arranged in series to form micropillars under a magnetic field. It is precisely because of the presence of magnetically responsive micropillars with shape memory behavior that the solid-phase extraction micropillar array chip of this invention possesses advantages such as high efficiency, high accuracy, and high flexibility.

[0021] The present invention also provides the application of the above-mentioned solid phase extraction micropillar array chip in solid phase extraction and speciation analysis of metal elements.

[0022] Preferably, the metallic element includes metallic silver; the silver is in the form of silver nanoparticles (Ag NPs) and silver ions (Ag). + ).

[0023] The technical principle of this invention is as follows: Based on 4D printing, an array of solid-phase extraction micropillar chips is constructed. Under the action of a magnetic field, the magnetically responsive micropillars constructed by multiple magnetic flowers in series promote the adsorption of metal elements, further realizing solid-phase microextraction of metal elements on a microfluidic platform, and achieving element speciation analysis through sequential desorption.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] (1) The method provided by the present invention combines 3D printing technology, 4D printing technology and microfluidic chip technology to construct an array solid phase extraction micropillar chip with magnetic response, giving full play to the advantages of 3D printing technology, 4D printing technology and microfluidic chip technology;

[0026] (2) The method provided by the present invention integrates 4D printed magnetic responsive structures in microfluidic channels, introducing intelligent, dynamic and real-time processing into the sample pretreatment process, so as to realize dynamic control of the solid phase extraction process, which has the advantages of high efficiency, high accuracy and high flexibility.

[0027] (3) The method provided by the present invention combines the characteristics of different 3D printing technologies to integrate multiple micropillars into a microfluidic chip, thereby realizing high-throughput analysis and rapid experimental process;

[0028] (4) The solid-phase extraction micropillar array chip constructed by the method of the present invention has a structure of multiple magnetic flowers connected in series. By optimizing the desorbent, sequential desorption can be performed, and the analysis and quantitative recovery of metal elements can be realized. Attached Figure Description

[0029] Figure 1 This is an image of the solid-phase extraction micropillar array chip prepared in Example 1 based on 4D printing; wherein, Figure 1 a. Design drawings and actual photos of magnetic flowers with magnetic response characteristics manufactured based on direct ink writing 3D printing; Figure 1 b shows actual photos and design drawings of micropillars based on DIW printing and micropillar shells based on LCD printing; Figure 1 c shows a photograph and design drawing of the assembled micropillar and shell; Figure 1 d is the design diagram of the micropillar array; Figure 1 e and f are actual photographs of the micropillar array;

[0030] Figure 2 It is a photograph of the shape of a single magnetic flower with magnetic response characteristics under the influence of a magnetic field;

[0031] Figure 3 The figure shows the optimization results of the adsorption efficiency of the solid-phase extraction micropillar array chip applied in Example 1; among them, Figure 3 a represents the effect of pH on adsorption efficiency; Figure 3 b represents the effect of the number of tandem magnetic flowers on the adsorption efficiency; Figure 3 c represents the influence of micropillar structure and composition on adsorption efficiency;

[0032] Figure 4 The figure shows the optimization results of the adsorption efficiency of the solid-phase extraction micropillar array chip applied in Example 2; among them, Figure 4 a~c represent the effect of sample flow rate on adsorption efficiency; Figure 4 d represents the effect of magnetic field current on adsorption efficiency;

[0033] Figure 5 The figure shows the optimization results of the solid-phase extraction micropillar array chip desorbent applied in Example 3;

[0034] Figure 6 Example 4 is used to examine sample volume and Ag. + The results of the ratio of Ag NPs and the effect of Ag NPs particle size on recovery rate are shown in the figure.

[0035] Figure 7 This is the result graph of the application example 5 to examine the reusability of the chip. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below. 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.

[0037] This invention provides a solid-phase extraction micropillar array chip based on 4D printing. The solid-phase extraction micropillar array chip includes a microextraction device; the microextraction device includes magnetically responsive micropillars formed by multiple magnetic flowers connected in series; the raw material of the magnetic flowers includes a blend of PDMS / Fe3O4 / SiO2.

[0038] In some examples, the mass ratio of PDMS, Fe3O4, and SiO2 is 1:(0.5~3):(0.01~1).

[0039] This invention also provides a method for constructing the above-mentioned solid-phase extraction micropillar array chip based on 4D printing, comprising the following steps:

[0040] (1) Preparation of magnetic flowers: PDMS / Fe3O4 / SiO2 blend was used to make magnetic flowers;

[0041] (2) Preparation of microextraction device: Multiple magnetic flowers are connected in series to form a microcolumn with magnetic response, and the microcolumn is combined with the shell of the microcolumn to obtain the microextraction device;

[0042] (3) Chip fabrication: Multiple microextraction devices are combined with an array shell to obtain a micropillar array chip.

[0043] In some examples, the diameter of the magnetic flower is 0.2 to 20 mm and the thickness is 0.1 to 2 mm.

[0044] In some examples, the magnetic flower has ≥3 petals.

[0045] In the following specific embodiments, the diameter of the magnetic flower is 6 mm, the thickness is 0.2 mm, and the number of petals of the magnetic flower is 6; the magnetic flower is obtained by DIW printing; the micro-pillar shell and the array shell are both obtained by LCD printing using DLP rigid resin as raw material; the micro-pillar is formed by multiple magnetic flowers connected in series through capillaries; in step (3), nine micro-extraction devices are combined with the array shell to obtain a micro-pillar array chip.

[0046] Example 1

[0047] A solid-phase extraction micropillar array chip based on 4D printing is constructed as follows:

[0048] (1) After mixing the PDMS / Fe3O4 / SiO2 blend in a homogenizer for 5 min (2500 r / min), it is loaded into a DIW printing syringe and then placed in a homogenizer for 5 min (2500 r / min) to remove air bubbles; the syringe is connected to the printing needle and the air path to print the magnetic flower; the mass ratio of PDMS, Fe3O4 and SiO2 is 1:2:0.02. Figure 1 Image a shows a photograph of a magnetic flower manufactured by DIW printing of a PDMS / Fe3O4 / SiO2 blend. The magnetic flower has a diameter of 6 mm, a thickness of 0.2 mm, and 6 petals. The printed object is consistent with the design size, and the reproducibility of multiple printings is good. Figure 2 A photograph showing the shape of a single magnetic flower with magnetic response characteristics under the influence of a magnetic field.

[0049] (2) Multiple magnetic flowers are connected in series through capillary tubes to form a micro-column structure with magnetic response. The micro-column shell is made by LCD printing. The micro-column and the micro-column shell are combined to construct a micro-extraction device containing an inlet (1 mm id), an outlet (1 mm id), and a micro-column. Figure 1 Figure b shows actual photos and design drawings of the micropillar based on DIW printing and the micropillar shell based on LCD printing, and the specific dimensions are marked in the design drawing of the micropillar shell; Figure 1 Figure c shows a photograph and design drawing of a microextraction device including an inlet, an outlet, and a microcolumn.

[0050] (3) Further array shells were constructed using LCD printing to integrate multiple micropillars to build a solid-phase extraction micropillar array chip; a nine-array was designed for Ag. + Simultaneous extraction of 10-15 nm Ag NPs and 50 nm Ag NPs under the same magnetic field, with three replicates for each sample. Figure 1 Figure d shows the design diagram of the micropillar array. Figure 1 Images e and f show actual photographs of the micropillar array.

[0051] Unless otherwise specified, the following application examples 1-5 all use the solid-phase extraction micropillar array chip constructed in Example 1 for Ag. + Solid-phase extraction and speciation analysis were performed on 10-15 nm Ag NPs and 50 nm Ag NPs.

[0052] Application Example 1

[0053] This application example examines the effects of sample pH, number of magnetic flowers, extraction column structure, and composition on adsorption efficiency.

[0054] like Figure 3 As shown in Figure a, the adsorption efficiency gradually increases with increasing pH, reaching a quantitative level; considering that Ag > 7.7, + Hydrolysis begins to form a precipitate, and pH 7 is selected for subsequent optimization of the number of magnetic flowers in the microcolumn.

[0055] The optimization results for the number of magnetic flowers in the micropillars, such as Figure 3 As shown in b, Ag can be achieved when the number of magnetic flowers in a single micropillar reaches 20 or more. + Quantitative adsorption of Ag NPs.

[0056] Figure 3 c represents the influence of micropillar structure and composition on adsorption efficiency; such as Figure 3 As shown in Figure c, the micropillars are cylindrical and magnetic flower structures, respectively. The components of the micropillars, from left to right, are: PDMS, PDMS / Fe3O4 (PDMS:Fe3O4 = 1:2), and PDMS / Fe3O4 / SiO2 (PDMS:Fe3O4:SiO2 = 1:2:0.02). The volumes of the cylindrical and magnetic flower pillars made from these components remain unchanged. As can be seen from the figure, the micropillars with a magnetic flower structure and the PDMS / Fe3O4 / SiO2 composition exhibit the highest adsorption efficiency.

[0057] Application Example 2

[0058] This application example uses 10~50 μL min -1 The effect of sample flow rate on adsorption efficiency was investigated within a certain range:

[0059] like Figure 4 As shown in figures a~4c, under non-magnetic field conditions, the magnetic flower micropillars for Ag + The adsorption efficiency of AgNPs is relatively low; under the action of a magnetic field (magnetic field strength 68.8~304.6 mT), the adsorption efficiency is 10~20 μL / min. -1 Ag can be achieved at all flow rates + Quantitative adsorption of AgNPs was observed; the adsorption efficiency gradually decreased with further increase in flow rate, therefore a flow rate of 20 μL / min was selected. -1The sample flow rate was then used for subsequent condition optimization. Different currents in the electromagnetic field correspond to different magnetic field strengths, and the effect of different currents in the electromagnetic field on adsorption was further investigated. Figure 4 As shown in d, the changes in current (1A, 2A, 3A) for Ag + The magnetic flower micropillars have little effect on 10-15 nm AgNPs and can achieve quantitative adsorption. This may be because the magnetic flower is thin and can achieve good deformation and shape memory at low current. Increasing the current can promote the adsorption of 50 nm AgNPs by the magnetic flower micropillars.

[0060] Application Example 3

[0061] This application example examines the desorption effect of the desorbent at different concentrations:

[0062] Studies have found that Na₂S₂O₃ has a good desorption effect on Ag NPs, and thiourea has a good desorption effect on Ag NPs. + It has good desorption effect. At a Na₂S₂O₃ concentration of 2 mmol / L... -1 ~20 mmol L -1 Its elution effect on Ag speciation was investigated, such as... Figure 5 As shown in Figure a, when the Na₂S₂O₃ concentration is greater than 10 mmol / L... -1 Ag NPs can be quantitatively recovered when the Na2S2O3 concentration is less than 10 mmol / L. -1 At that time, Ag + The recovery rate (<8%) was negligible. Further investigation was conducted using 2 mol L of thiourea containing 0.1%–4% thiourea. -1 The elution effect of HNO3 on Ag speciation, such as Figure 5 As shown in b, when the thiourea concentration reaches 1% (w / v), Ag + It can be quantitatively recovered, as evidenced by the use of 10 mM Na2S2O3 and 2 mol L of thiourea containing 1% (w / v) respectively. -1 HNO3 can realize Ag NPs and Ag + Sequential desorption to achieve Ag NPs and Ag + Separation of the two Ag speciations. Subsequently, the effect of different concentrations of nitric acid in 1% thiourea on the recovery rates of the two Ag speciations was investigated, such as... Figure 5 As shown in Figure c, the recovery rates of both Ag forms continuously increase with increasing nitric acid concentration. When the HNO3 concentration is 0.5 mol / L... -1 At that time, Ag + It can be quantitatively recovered when the HNO3 concentration reaches 2 mol L. -1 Ag NPs have not yet achieved quantitative recovery. Figure 5b shows that the two Ag forms in 2 mol L of thiourea containing 4% (w / v) -1 Quantitative recovery was achieved in HNO3 solution, but considering that excessively high concentrations of nitric acid might damage Fe3O4 in the microcolumn, 10 mM Na2S2O3 and 0.5 mol L of thiourea containing 1% (w / v) were ultimately chosen. -1 HNO3 solution was used as Ag NPs and Ag, respectively. + Sequential desorbents.

[0063] With a fixed sample volume of 1 mL, samples were prepared using 10 mM Na₂S₂O₃(a) and 0.5 mol L⁻¹ thiourea containing 1% (w / v) thiourea. -1 HNO3(b) solution as Ag NPs and Ag + The effects of different eluent dosages on AgNPs and Ag in sequential desorption were investigated. + The effect of recovery rate. The target Ag speciation was sequentially desorbed using four 50 μL portions of each of the two desorbents, and the results are as follows: Figure 5 As shown in d and 5e, when the volume of desorbent (a) reaches 100 μL, quantitative desorption of Ag NPs can be achieved; when the volume of desorbent (b) is 50 μL, quantitative desorption of Ag NPs can be achieved. + Quantitative desorption was performed; therefore, Ag NPs and Ag were selected. + The desorption volumes were 100 and 50 μL, respectively.

[0064] Application Example 4

[0065] This application example examines sample volume and Ag. + The effect of Ag NP concentration ratio and Ag NP particle size on recovery rate:

[0066] Sample volume is closely related to the analytical speed and enrichment fold of the method. With the amounts of the two Ag speciations in the sample fixed at 10 ng each, the effect of sample volume on Ag NPs and Ag enrichment was investigated within the range of 0.1–5.0 mL. + The impact of recovery rate. For example... Figure 6 As shown in a, within the scope of the investigation, the microcolumns can achieve quantitative recovery of both Ag forms.

[0067] Considering both enrichment factor and analysis speed, 1.0 mL was chosen as the sample volume. This is because Ag in actual samples... + The concentrations of Ag and Ag NPs are uncertain, and there is an interconversion between them; therefore, it is necessary to investigate different proportions of Ag. + The effect of / Ag NPs. This method on Ag + The linear ranges for Ag NPs and Ag NPs are 0.01–100 μg / L, respectively.-1 0.02~100 μg / L -1 In Ag + The effect of sequential desorption on the recovery of the two Hg speciations was investigated within the concentration ratio of / Ag NPs ranging from 1:9 to 9:1. The results are as follows: Figure 6 As shown in b. The results indicate that Ag + Both Ag and Ag NPs can be quantitatively recovered within the studied range, indicating that this method can recover a certain proportion of Ag in actual samples. + Ag NPs analysis has good application potential.

[0068] Considering that the particle size of Ag NPs in actual samples is uncertain, the adsorption and desorption behavior of Ag NPs with different particle sizes was investigated. The results are as follows: Figure 6 As shown in Figure c, it can be seen that the recovery rate of Ag NPs decreases slightly with increasing particle size, but this does not affect the recovery rate of Ag. + The method achieves a high recovery rate, enabling quantitative recovery of Ag NPs (4~70 nm) over a wide particle size range.

[0069] Application Example 5

[0070] This comparative example examines the reusability of solid-phase extraction micropillar array chips:

[0071] After extracting Ag speciation using the prepared chip under optimal conditions, the chip micropillars were regenerated with HNO3 and NH4Ac solutions. For example... Figure 7 As shown, after the same chip is used 200 times, Ag + Both Ag NPs and Ag NPs can be recovered quantitatively, and the recovery rate does not decrease significantly.

[0072] Example 2

[0073] A solid-phase extraction micropillar array chip based on 4D printing is constructed in a manner that is basically the same as in Example 1, except that the mass ratio of PDMS, Fe3O4, and SiO2 in this example is 1:0.5:0.01.

[0074] Example 3

[0075] A solid-phase extraction micropillar array chip based on 4D printing is constructed in a manner that is basically the same as in Example 1, except that the mass ratio of PDMS, Fe3O4, and SiO2 in this example is 1:3:0.01.

[0076] Example 4

[0077] A solid-phase extraction micropillar array chip based on 4D printing is constructed in a manner that is basically the same as in Example 1, except that the mass ratio of PDMS, Fe3O4, and SiO2 in this example is 1:0.5:1.

[0078] Example 5

[0079] A solid-phase extraction micropillar array chip based on 4D printing is constructed in a manner that is basically the same as that in Example 1, except that the mass ratio of PDMS, Fe3O4 and SiO2 in this example is 1:3:1.

[0080] Example 6

[0081] A solid-phase extraction micropillar array chip based on 4D printing is constructed in a manner that is basically the same as in Example 1, except that the mass ratio of PDMS, Fe3O4, and SiO2 in this example is 1:2:0.5.

[0082] The solid-phase extraction micropillar array chip provided by this invention integrates a 4D-printed magnetically responsive structure in a microfluidic channel, enabling high-throughput analysis and rapid experimental processes. Experimental verification by the inventors shows that the solid-phase extraction micropillar array chips obtained in Examples 2-6 can all be used for solid-phase extraction and speciation analysis of metal elements, possessing advantages such as high efficiency, high accuracy, and high flexibility. Specifically, by optimizing the relevant parameters of the adsorption process of the solid-phase extraction micropillar array chips obtained in Examples 2-6, quantitative adsorption of metal elements can be achieved; and by optimizing the desorption process of the solid-phase extraction micropillar array chips obtained in Examples 2-6, sequential desorption and quantitative recovery of metal speciation can be achieved.

[0083] This invention uses a PDMS / Fe3O4 / SiO2 blend as a material with shape memory effect. Magnetic flowers constructed from the PDMS / Fe3O4 / SiO2 blend exhibit shape memory behavior, deforming under magnetic field stimulation and recovering their initial shape by controlling the magnetic field. Micropillars formed by arranging multiple magnetic flowers closely together in series also exhibit a similar phenomenon under a magnetic field. It is precisely because of the presence of magnetically responsive micropillars with shape memory behavior that the solid-phase extraction micropillar array chip of this invention possesses advantages such as high efficiency, high accuracy, and high flexibility.

[0084] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A solid-phase extraction micropillar array chip based on 4D printing, characterized in that, The solid-phase extraction microcolumn array chip includes a microextraction device; the microextraction device includes a magnetically responsive microcolumn composed of multiple magnetic flowers connected in series; the raw material of the magnetic flowers includes a blend of PDMS / Fe3O4 / SiO2, wherein the mass ratio of PDMS, Fe3O4, and SiO2 is 1:(0.5~3):(0.01~1).

2. The solid-phase extraction micropillar array chip based on 4D printing according to claim 1, characterized in that, The mass ratio of PDMS, Fe3O4, and SiO2 is 1:2:0.

02.

3. A method for constructing a solid-phase extraction micropillar array chip based on 4D printing as described in any one of claims 1 to 2, characterized in that, Includes the following steps: (1) Preparation of magnetic flowers: PDMS / Fe3O4 / SiO2 blend was used to make magnetic flowers; (2) Preparation of microextraction device: Multiple magnetic flowers are connected in series to form a microcolumn with magnetic response, and the microcolumn is combined with the shell of the microcolumn to obtain the microextraction device; (3) Chip fabrication: Multiple microextraction devices are combined with an array shell to obtain a micropillar array chip.

4. The method for constructing a solid-phase extraction micropillar array chip based on 4D printing according to claim 3, characterized in that, The magnetic flowers are obtained by direct ink writing and printing; the micropillar shell and array shell are obtained by LCD printing.

5. The method for constructing a solid-phase extraction micropillar array chip based on 4D printing according to claim 3, characterized in that, The diameter of the magnetic flower is 0.2~20 mm and the thickness is 0.1~2 mm.

6. The method for constructing a solid-phase extraction micropillar array chip based on 4D printing according to claim 3, characterized in that, The micropillar is composed of multiple magnetic flowers connected in series via capillary tubes.

7. The method for constructing a solid-phase extraction micropillar array chip based on 4D printing according to claim 3, characterized in that, In step (3), nine microextraction devices are combined with an array shell to obtain a micropillar array chip.

8. The application of a 4D-printed solid-phase extraction micropillar array chip as described in any one of claims 1 to 2 in solid-phase extraction and morphology analysis of metal elements.

9. The application of a 4D-printed solid-phase extraction micropillar array chip according to claim 8 in solid-phase extraction and speciation analysis of metal elements, characterized in that, The metallic element includes silver.

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