Flexible wearable sweat multi-parameter detection micro-fluidic chip as well as preparation method and application thereof

Abstract

The invention discloses a flexible wearable sweat multi-parameter detection micro-fluidic chip as well as a preparation method and application thereof, and belongs to the technical field of micro-fluidic chips. The micro-fluidic chip comprises a sealing cover layer, a PDMS circulation channel layer with a micro-fluidic channel and a detection chamber, a paper chip modified by a detection reagent and a bonding layer, the PDMS circulation channel layer is filled with the detection reagent modified paper chip, the PDMS circulation channel layer is covered with the sealing cover layer, and the bonding layer is located below the PDMS circulation channel layer. The flexible micro-fluidic detection chip has the beneficial effects that the flexible micro-fluidic detection chip can be directly worn on the surface of skin, can realize simultaneous, in-situ and rapid detection of various markers, perspiration rate and temperature in sweat without complex pretreatment steps such as sweat collection, sampling and sample preparation, avoids pollution and evaporation of sweat, and improves the detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of microfluidic chips, and in particular to a flexible wearable sweat multi-parameter detection microfluidic colorimetric chip and a preparation method and application thereof. Background Art

[0002] Sweat is a physiological fluid that is easy to obtain and can be collected in a completely non-invasive way. Sweat contains a variety of biomarkers, which are closely related to a variety of diseases. For example, the chloride ion content in sweat is a detection indicator of cystic fibrosis, the pH value of sweat is an indicator of metabolic alkalosis, the urea concentration in sweat can be used as a monitoring indicator of kidney function, and the magnesium ion concentration in sweat is closely related to diseases such as muscle health and arrhythmia. Detecting changes in sweat rate in different parts of the body provides important clues for autonomic thermal regulation and recovery in stroke patients. In addition, simultaneous monitoring of sweat rate, electrolyte concentration and temperature can provide important clues for understanding the possibility of heat exhaustion and heat stroke under extreme environmental conditions. The detection of sweat biomarkers, sweat rate and temperature provides the possibility of non-invasive human health monitoring, disease diagnosis and personalized health management. Traditional sweat detection methods usually require the use of absorbent pads, and sweat samples are collected manually, and then the content of related components is detected by laboratory instruments. This detection mode has problems such as complex detection methods, long detection time, large consumption of samples, reagents and labor, possible contamination of samples, and delayed detection information.

[0003] Microfluidic chips integrate sample collection, transportation, reaction, separation, detection and other operation units, and have the advantages of high efficiency, rapidity, low cost, portability, and low consumption of samples and reagents. The development of flexible wearable microfluidic detection chips that can fit tightly to the surface of human skin can realize in-situ sampling, transportation, flow control, storage, reaction and detection of trace sweat, avoid cumbersome sweat collection and pretreatment, improve the accuracy and efficiency of sweat detection, and is a good platform for real-time and rapid detection of sweat. In recent years, the research and development of flexible wearable sweat sensors has attracted the attention of more and more researchers. However, there are still few flexible wearable microfluidic chips that can realize rapid detection of multiple parameters in sweat at the same time.

[0004] The Chinese patent application document with publication number CN115791935A discloses a microfluidic chip for parallel detection of sweat multi-parameters. After three parallel reaction chambers are inserted into three electrode mechanisms, glucose, lactate and Na can be detected. +Detection of content. Microfluidic detection chips based on electrochemical detection technology usually require external power supplies and circuit systems, which are costly and not conducive to portable detection. Microfluidic colorimetric detection chips do not require power supplies and circuit systems, and have the advantages of simple device, easy operation, portability, and low cost. They occupy an important position in the development of wearable detection devices. Therefore, the development of flexible wearable sweat multi-parameter detection microfluidic colorimetric chips to realize real-time and rapid detection of multiple markers, sweat rate and temperature in sweat is of great significance for the detection of various diseases and personal health monitoring. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to provide a flexible wearable sweat multi-parameter detection microfluidic chip and its preparation method and application, so as to solve the technical problems that the existing commercial sweat detection methods require manual sampling, offline detection, are not portable, and have difficulty in achieving simultaneous rapid detection of multiple markers and physical indicators in sweat.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] The first aspect of the present invention provides a flexible wearable sweat multi-parameter detection microfluidic chip, comprising a capping layer, a PDMS flow channel layer with a microfluidic channel and a detection chamber, a paper chip modified with a detection reagent, and an adhesive layer;

[0008] The detection reagent modified paper chip is loaded on the PDMS flow channel layer, the capping layer covers the PDMS flow channel layer, and the adhesive layer is located below the PDMS flow channel layer;

[0009] The center, inner periphery and outer periphery of the PDMS flow channel layer are sequentially provided with a sweat temperature detection area, a multi-marker detection area and a sweat rate detection area; the sweat temperature detection area includes a central chamber and a flow channel connected to the atmosphere; the multi-marker detection area is divided into a plurality of groups of detection areas, each group of detection areas includes a sampling hole and a plurality of branched detection chambers connected by capillary rupture valves (CBVs) with different bursting pressures; the sweat rate detection area is composed of a sampling hole and a curved flow channel containing a plurality of small chambers;

[0010] The detection reagent modified paper chip is obtained by modifying filter paper with different detection reagents or dyes of different colors.

[0011] Preferably, the multi-marker detection zone includes a pH detection zone, a urea detection zone, a chloride ion detection zone and a magnesium ion detection zone.

[0012] Preferably, the paper chip modified with the detection reagent includes a sweat temperature detection paper chip, a pH detection paper chip, a urea detection paper chip, a chloride ion detection paper chip, a magnesium ion detection paper chip and a sweat rate detection paper chip;

[0013] The sweat temperature detection paper chip, pH detection paper chip, urea detection paper chip, chloride ion detection paper chip, and magnesium ion detection paper chip are respectively matched with the chambers of the sweat temperature detection area, pH detection area, urea detection area, chloride ion detection area, magnesium ion detection area, and sweat sweat rate detection area on the PDMS flow channel layer.

[0014] Preferably, the sweat temperature detection paper chip is obtained by coating a ternary cholesteric liquid crystal mixture consisting of cholesterol oleyl carbonate (COC), cholesterol nonanoate (CN) and 2,4-dichlorobenzoic acid cholesterol ester (CD) on a filter paper.

[0015] The pH detection paper chip is obtained by dripping a pH detection reagent onto a filter paper sheet, wherein the pH detection reagent is a mixed solution of bromocresol purple, bromocresol green and bromothymol blue.

[0016] The urea detection paper chip is obtained by dissolving p-dimethylaminobenzaldehyde in a sulfuric acid solution and then dripping the solution onto a filter paper.

[0017] The chloride ion detection paper chip is a mixture of mercuric thiocyanate ethanol solution and Fe(NO 3 ) 3 The solution is added dropwise onto a filter paper.

[0018] The magnesium ion detection paper chip is obtained by dropping an chrome black T solution onto a filter paper sheet.

[0019] The sweat rate detection paper chip is obtained by respectively soaking a plurality of filter paper sheets in dyes of different colors, so as to obtain a plurality of sweat rate detection paper chips of different colors.

[0020] Preferably, the capping layer is made of PDMS film or other flexible transparent materials such as nano glue, PET film, etc. Preferably, the thickness of the capping layer is 0.2 mm.

[0021] Preferably, the adhesive layer is any one of a PDMS film treated with oxygen plasma or an adhesive, a transparent medical double-sided tape, and a double-sided adhesive film; a plurality of injection ports are provided on the adhesive layer. Preferably, the thickness of the adhesive layer is 0.2 mm.

[0022] Preferably, the injection port on the adhesive layer corresponds to the injection hole of the PDMS flow channel layer.

[0023] The second aspect of the present invention proposes a method for preparing the above-mentioned flexible wearable sweat multi-parameter detection microfluidic chip, comprising the following steps: loading the paper chip modified with the detection reagent into the chamber corresponding to the PDMS flow channel layer, covering the capping layer on the PDMS flow channel layer, placing the adhesive layer under the PDMS flow channel layer, and encapsulating the adhesive layer after the injection port of the adhesive layer corresponds to the injection hole position of the PDMS flow channel layer.

[0024] The third aspect of the present invention proposes the application of the above-mentioned flexible wearable sweat multi-parameter detection microfluidic chip in sweat multi-parameter detection.

[0025] Preferably, the method comprises the following steps:

[0026] (1) A flexible wearable sweat multi-parameter detection microfluidic chip is attached to different parts of human skin, and sweat is produced by exercise, and the sweat flows into the chip through the sampling port of the microfluidic chip;

[0027] (2) After the sweat flows through each detection chamber or small chamber of the microfluidic chip and a color reaction occurs, a color image of the microfluidic chip is obtained by taking a photo, and the RGB value of the image of each detection area is further obtained using image editing software. The concentration of various biomarkers in the sweat is calculated, the body surface temperature is read through the color information, and the sweat rate is calculated through the color bar and the detection time.

[0028] The application of the flexible wearable sweat multi-parameter detection microfluidic chip of the present invention is to use the flexible wearable microfluidic chip for simultaneous detection of multiple markers in sweat, epidermal sweat temperature and sweat rate, and comprises the following steps:

[0029] Step 1: Referring to the above preparation method, according to the type of sweat biomarker to be measured, the corresponding detection reagent is modified on the paper chip, and loaded into the corresponding detection chamber of the PDMS flow channel layer, and then packaged to prepare a flexible wearable sweat multi-parameter detection microfluidic chip.

[0030] Step 2: Stick the prepared flexible wearable sweat multi-parameter detection microfluidic chip to different parts of human skin, sweat through exercise or other means, and the sweat flows into the microfluidic chip through the inlet of the microfluidic chip.

[0031] Step 3: After the sweat flows through the various detection chambers of the microfluidic chip and a color reaction occurs, a photo is taken with a mobile phone to obtain a color image of the microfluidic chip. The RGB value of the image of each detection area is further obtained using image editing software (such as ImageJ software). The concentration of various biomarkers in sweat is calculated according to the calculation formula, the body surface temperature is read through the colorimetric information, and the sweat rate is calculated through the colorimetric bar and the detection time.

[0032] The beneficial effects of the present invention are:

[0033] 1. The flexible microfluidic detection chip of the present invention can be directly worn on the skin surface without complicated pretreatment steps such as sweat collection, sampling, and sample preparation, and can realize simultaneous, in-situ, and rapid detection of multiple markers in sweat, thus avoiding contamination and evaporation of sweat and improving the accuracy of detection.

[0034] 2. The flexible wearable sweat multi-parameter detection microfluidic chip of the present invention is easy to prepare, low-cost, simple to operate, portable, and uses less reagents and samples. The main part of the microfluidic chip is reusable. Combined with smartphone detection software, it can realize simultaneous, real-time and rapid detection of multiple markers and physical indicators in sweat, and has important application prospects in personal health monitoring and disease early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural diagram of the PDMS flow channel layer with microfluidic channels and detection chambers and an enlarged structural diagram of the detection area of ​​the flexible wearable sweat multi-parameter detection microfluidic chip in Example 1.

[0036] Figure 2 It is a three-dimensional structural diagram of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 1.

[0037] Figure 3 This is a bending photo of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 1.

[0038] Figure 4 This is a picture of the pH detection chamber of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 2 when sweat of different pH values ​​are present ( Figure 4 a) and the correlation fitting diagram between the R, G, B value change rate of the detection chamber image and the sweat pH ( Figure 4 b).

[0039] Figure 5 This is a picture of the urea detection chamber of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 2 when urea of ​​different concentrations are present ( Figure 5 a) and the correlation fitting diagram between the B value change rate of the detection chamber image and the sweat urea concentration ( Figure 5 b).

[0040] Figure 6 This is a picture of the chloride ion detection chamber of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 2 when different concentrations of chloride ions exist ( Figure 6 a) and the correlation fitting diagram of the G value change rate of the detection chamber image and the sweat chloride ion concentration ( Figure 6 b).

[0041] Figure 7This is a picture of the magnesium ion detection chamber of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 2 when different concentrations of magnesium ions are present ( Figure 7 a) and the correlation fitting diagram between the R value of the detection chamber image and the sweat magnesium ion concentration ( Figure 7 b).

[0042] Figure 8 This is a picture of the temperature detection chamber of the flexible wearable sweat multi-parameter detection microfluidic chip on the skin surface at different temperatures in Example 2 ( Figure 8 a) and the correlation fitting diagram between the R, G, B values ​​of the temperature detection chamber image and the skin temperature ( Figure 8 b).

[0043] Fig. 9 These are photos of the flexible wearable sweat multi-parameter detection microfluidic chip in Example 2 when sweat at different flow rates flows through cavities of different colors in the sweat rate detection channel. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0046] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0047] Embodiment 1:

[0048] A flexible wearable sweat multi-parameter detection microfluidic chip comprises a capping layer, a PDMS flow channel layer with a microfluidic channel and a detection chamber, a paper chip modified with a detection reagent, and an adhesive layer; the paper chip modified with the detection reagent is loaded on the PDMS flow channel layer, the capping layer covers the PDMS flow channel layer, and the adhesive layer is located below the PDMS flow channel layer;

[0049] The center, inner periphery and outer periphery of the PDMS flow channel layer are successively provided with a sweat temperature detection area, a multi-marker detection area and a sweat rate detection area; the sweat temperature detection area includes a central chamber and a flow channel connected to the atmosphere; the inner periphery multi-marker detection area is divided into four groups of detection areas, each of which includes an injection hole and three branched detection chambers connected by capillary rupture valves (CBVs) with different burst pressures. By changing the geometric structure of the CBV valve and adjusting the burst pressure of the three valves, sweat can flow into the three detection chambers in turn, realizing continuous detection of sweat markers over a period of time. Three neck-shaped slender pressure relief channels with high burst pressure CBV valves are designed on the other side of each chamber to avoid the situation where the reservoir cannot be filled due to the back pressure of the chamber during the process of sweat filling the chamber. After filling one chamber, the sweat will accumulate pressure to open the next CBV valve on the main channel and flow to the next chamber. Finally, the sweat fills the three chambers, the slender pressure relief channel ruptures, and the sweat finally gathers in the annular drainage flow channel outside the detection area. The annular drainage flow channel is connected in parallel to four groups of sweat biomarker detection areas and is connected to the external atmosphere. The four groups of detection areas have a total of 12 detection chambers, which are filled with paper chips modified with different detection reagents, and can be used for the simultaneous detection of multiple markers; the peripheral sweat sweat rate detection area consists of an injection hole and a curved flow channel containing four small chambers. The sweat rate is measured by the color bars of different colors produced by sweat flowing through different chambers and the time required.

[0050] Prepare a flexible wearable sweat multi-parameter detection microfluidic chip. The specific production and assembly process is as follows:

[0051] 1) First, use SolidWorks software to design the positive mold three-dimensional structure of the PDMS circulation channel layer, and prepare the positive mold mold by 3D printing or soft lithography technology. The design parameters of the mold are as follows: the diameter of the circular mold base is 42mm, the thickness is 2mm, a protruding pattern is set on the base, the pattern protrusion height is 0.3mm, and a circle of 2mm high fence is added to the outside of the mold. The protruding pattern includes four groups of detection area positive mold patterns. Each group of detection area positive mold patterns includes 3 CBV valves connected by a protruding channel with a width of 0.3mm, 3 circular protrusions with a diameter of 3mm, and each circular protrusion is connected to the outside of three neck-shaped slender pressure relief protrusion channels with a width of 0.2 at the thin part and a width of 0.3mm at the wide part, and is connected to a peripheral annular pressure relief protrusion channel with a width of 0.5mm. The protruding pattern also includes a circular protrusion with a central diameter of 3mm connected to a linear protrusion channel with a width of 0.2mm. The protruding pattern also includes a surrounding curved protruding channel with a peripheral width of 0.8 mm, and the channel includes four circular protrusions with a diameter of 1.4 mm.

[0052] 2) A flexible PDMS flow channel layer with microfluidic channels and detection chambers was prepared by the reverse molding method. The structure diagram is shown in the attached figure. Figure 1 As shown. The preparation process is as follows: the main agent and curing agent for preparing PDMS are mixed in a ratio of 10:1, stirred in a beaker for 30 minutes at a speed of 150rpm to form a PDMS prepolymer, the PDMS prepolymer is placed in a vacuum chamber to remove excess bubbles, and finally poured evenly into the processed circular mold, placed in a drying oven at 70°C for 2 hours, and finally demolded to obtain a PDMS circulation channel layer with a microfluidic channel and a detection chamber. The size of the PDMS circulation channel layer with microfluidic channels and chambers is 40mm in diameter and 0.3mm in thickness. The depth of the microfluidic channel and the detection chamber is 0.3mm. A non-ionic surfactant is used to perform surface hydrophilic modification on the PDMS channel layer with microfluidic channels and chambers. Finally, a PDMS puncher is used to punch 6 injection holes with a diameter of 0.3mm at specific positions of the PDMS channel layer.

[0053] 3) Prepare the paper chip modified with the detection reagent. The preparation steps are as follows:

[0054] First, prepare the various detection reagents needed. Use a plotter to prepare Whatman No. 1 filter paper into a circular filter paper sheet with a diameter of 3 mm.

[0055] 3 μL of pH detection reagent was added dropwise onto the circular filter paper and dried for 5 min to obtain a pH detection paper chip. The pH detection reagent was a mixed solution of bromocresol purple, bromocresol green and bromothymol blue.

[0056] The urea detection reagent is 0.1450 g of p-dimethylaminobenzaldehyde dissolved in 4.0 mol / L sulfuric acid solution. 3 μL of urea detection reagent is added dropwise to a circular filter paper and dried for 3 min to obtain a urea detection paper chip.

[0057] The chloride ion detection reagent is 5g / L mercuric thiocyanate ethanol solution and 8g / L Fe(NO 3 ) 3 On the circular filter paper, add 3 μL of mercuric thiocyanate ethanol solution and dry for 1 min, then add 2 μL of Fe(NO 3 ) 3 The solution was dried for 2 min to obtain a chloride ion detection paper chip.

[0058] The magnesium ion detection reagent is 1 mM chrome black T solution. 3 μL of chrome black T solution is added dropwise onto a circular filter paper sheet and dried for 3 min to obtain a magnesium ion detection paper chip.

[0059] The sweat temperature detection reagent is a ternary cholesteric liquid crystal mixture composed of 40wt% cholesterol oleyl carbonate (COC), 40wt% cholesterol nonanoate (CN) and 20wt% 2,4-dichlorobenzoic acid cholesterol ester (CD). The mixture is applied on a circular filter paper taped with black tape to obtain a paper chip for sweat detection liquid temperature.

[0060] The circular filter paper pieces were immersed in yellow, green, orange and blue dyes respectively, taken out and dried for 3 minutes to obtain four colors of sweat rate detection paper chips.

[0061] 4) Commercially available nano glue was used as the capping layer, with a diameter of 40 mm and a thickness of 0.2 mm.

[0062] 5) Use a hole puncher to punch six 2 mm injection holes at specific locations of the double-sided medical tape and use it as the adhesive layer. The adhesive layer has a diameter of 40 mm and a thickness of 0.2 mm.

[0063] 6) Packaging and assembly method of flexible wearable sweat multi-parameter detection microfluidic chip Figure 2 shown.

[0064] A flexible wearable sweat multi-parameter detection microfluidic chip was assembled and prepared using a capping layer, a PDMS flow channel layer with microfluidic channels and chambers, a paper chip modified with a detection reagent, and an adhesive layer. The specific assembly scheme is as follows:

[0065] The paper chip modified with the detection reagent is embedded in the circular detection chamber corresponding to the prepared PDMS channel layer with microfluidic channels and chambers. Specifically, three paper chips for detecting sweat pH, urea, chloride ions and magnesium ions are respectively loaded into three detection chambers corresponding to the four detection areas, so that the four markers can be detected simultaneously. The paper chip for detecting epidermal temperature is placed in the central chamber. The four colors of yellow, green, orange and blue paper chips for sweat rate detection are loaded into the four small chambers of the peripheral sweat rate detection channel in order.

[0066] The capping layer is covered on the PDMS flow channel layer filled with the paper chip, and the adhesive layer is placed under the PDMS flow channel layer. The center position of the 6 injection holes of the adhesive layer corresponds to the position of the 6 injection holes of the PDMS flow channel layer, and the PDMS microfluidic channel can be encapsulated to obtain a flexible wearable sweat multi-parameter detection microfluidic chip. The flexible wearable sweat multi-parameter detection microfluidic chip prepared by artificial bending still maintains a good structure, indicating that the prepared flexible wearable sweat multi-parameter detection microfluidic chip has good flexibility, such as Figure 3 shown.

[0067] Embodiment 2:

[0068] In order to demonstrate the beneficial effects of the present invention, the flexible wearable sweat multi-parameter detection microfluidic chip of Example 1 was used to detect multiple biomarkers, epidermal temperature and sweat rate in sweat. The specific method is as follows:

[0069] 1) First, a flexible wearable sweat multi-parameter detection microfluidic chip was prepared according to Example 1.

[0070] 2) Prepare simulated sweat standard solutions containing markers at different concentrations.

[0071] 3) The simulated sweat standard solutions containing different concentrations of markers were injected into the six injection holes of the microfluidic chip. In the marker detection area, the sweat flowed from the four injection holes into four groups of detection areas in four directions. The sweat flowed into the three detection chambers of each detection area in turn through the CBV valve until the paper chips in the three chambers were soaked. After reacting at room temperature for 1 minute, the excess sweat was collected in the outer annular drainage flow channel.

[0072] 4) Take photos with a smartphone to obtain image data of the flexible wearable sweat multi-parameter detection microfluidic chip. Use ImageJ software to obtain the RGB value of the paper chip image in the detection area, and use origin software to process the experimental data for quantitative calculation.

[0073] As the pH of sweat changes from 4.0 to 7.5, the paper chip in the pH detection chamber changes from yellow to green and then to blue, achieving visual detection of sweat pH. Figure 4 A linear fitting curve is drawn between the sweat pH and the RGB colorimetric signal of the detection area, as shown in Figure 4 b. Based on the change rate of the R, G and B values ​​in the detection area relative to the blank paper chip, the quantitative determination of pH can be achieved.

[0074] The yellow color of the paper chip in the urea detection chamber gradually deepens as the urea concentration increases. Figure 5 A linear fitting curve is drawn between the sweat urea concentration and the change rate of the detection area R value relative to the blank paper chip, as shown in Figure 5 According to the change rate of the R value in the detection area, the quantitative determination of urea can be achieved, and the detection range is 0-200mM.

[0075] The reddish brown color of the paper chip in the chloride ion detection chamber gradually deepens as the chloride ion concentration increases. Figure 6 A linear fitting curve is drawn between the sweat chloride ion concentration and the change rate of the G value in the detection area, as shown in Figure 6 According to the change rate of the G value in the detection area, the quantitative determination of chloride ions can be achieved, and the detection range is 0-160mM.

[0076] The color of the paper chip in the magnesium ion detection chamber gradually changes from blue to purple as the magnesium ion concentration increases. Figure 7 A linear fitting curve is drawn between the sweat magnesium ion concentration and the R value change value of the corresponding detection area, as shown in Figure 7 According to the change of R value in the detection area, the quantitative determination of magnesium ions can be achieved, and the detection range is 0-10mM.

[0077] The microfluidic chip epidermal sweat temperature detection area is black when the sweat temperature is 31°C or below. When the sweat temperature is from 32°C to 33.5°C, the detection area gradually changes from pink to a deeper red, from 34°C to 36°C, it gradually changes from green to blue, and from 36°C to 38°C, it gradually changes from blue to purple. Therefore, visual monitoring of epidermal sweat within the range of 31-37°C can be achieved based on the chromaticity of the central temperature detection area. Figure 8 shown.

[0078] The peristaltic pump flow rate is changed to simulate sweat with different sweat rates (0.12-1.2 μL / min). Sweat with different sweat rates will flow through the four chambers of different colors in the sweat rate detection channel of the microfluidic chip in sequence after different time periods, producing chromaticity bars of different colors, such as Fig. 9 The time required for sweat of different sweat rates to flow through the four color chambers of the sweat rate detection channel is shown in Table 1. The sweat rate of sweat can be calculated based on the time required for sweat to flow through the detection chambers of different colors.

[0079] Table 1. The time required for sweat of different sweat rates to flow through the four color sweat rate detection chambers

[0080]

[0081]

[0082] Embodiment 3:

[0083] In order to demonstrate the beneficial effects of the present invention, the flexible wearable sweat multi-parameter detection microfluidic chip of Example 1 was used to detect biomarkers, epidermal temperature and sweat rate in actual sweat of healthy human body, and the specific method was as follows:

[0084] 1) First, a flexible wearable sweat multi-parameter detection microfluidic chip was prepared according to Example 1.

[0085] 2) The prepared flexible wearable sweat multi-parameter detection microfluidic chip is attached to the arm of the athlete until the sweat soaks the detection area paper chip through capillary action. After 1 minute, take a picture to obtain the image data of the microfluidic chip, use ImageJ software to obtain the RGB value of each detection area of ​​the microfluidic chip, and further calculate the pH, urea, chloride ion and magnesium ion concentration in the actual sweat according to the linear fitting curve of Example 2. According to the chromaticity information of the central temperature detection area, the epidermal sweat temperature is obtained. According to the time required for sweat to flow through the yellow detection chamber of sweat rate, the sweat sweat rate is calculated. The test results are shown in Table 2.

[0086] Table 2. Flexible wearable sweat multi-parameter detection microfluidic chip for healthy human sweat detection data

[0087]

[0088]

[0089] The above test results are consistent with the corresponding biomarker content, epidermal temperature and sweat rate in normal human sweat. Therefore, the flexible wearable sweat multi-parameter detection microfluidic chip of the present invention can be used for simultaneous detection of multiple biomarkers, epidermal sweat temperature and sweat rate in actual human sweat.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible wearable sweat multi-parameter detection microfluidic chip, characterized in that: It comprises a capping layer, a PDMS flow channel layer, a paper chip modified with a detection reagent and an adhesive layer; the paper chip modified with the detection reagent is loaded on the PDMS flow channel layer, the capping layer covers the PDMS flow channel layer, and the adhesive layer is located below the PDMS flow channel layer; the center, inner periphery and outer periphery of the PDMS flow channel layer are sequentially provided with a sweat temperature detection area, a multi-marker detection area and a sweat sweat rate detection area; the sweat temperature detection area comprises a central chamber and a flow channel connected to the atmosphere; the multi-marker detection area is divided into a plurality of groups of detection areas, each group of detection areas comprises a sampling hole and a plurality of branched detection chambers connected by capillary rupture valves (CBVs) with different bursting pressures; the sweat sweat rate detection area consists of a sampling hole and a curved flow channel containing a plurality of small chambers; the paper chip modified with the detection reagent is obtained by modifying filter paper with different detection reagents or dyes of different colors.

2. The flexible wearable sweat multi-parameter detection microfluidic chip according to claim 1, characterized in that: The multi-marker detection area includes a pH detection area, a urea detection area, a chloride ion detection area and a magnesium ion detection area; the detection reagent-modified paper chip includes a sweat temperature detection paper chip, a pH detection paper chip, a urea detection paper chip, a chloride ion detection paper chip, a magnesium ion detection paper chip and a sweat rate detection paper chip.

3. The flexible wearable sweat multi-parameter detection microfluidic chip according to claim 2 is characterized in that: The sweat temperature detection paper chip, pH detection paper chip, urea detection paper chip, chloride ion detection paper chip, and magnesium ion detection paper chip are respectively matched with the chambers of the sweat temperature detection area, pH detection area, urea detection area, chloride ion detection area, magnesium ion detection area, and sweat sweat rate detection area on the PDMS flow channel layer.

4. The flexible wearable sweat multi-parameter detection microfluidic chip according to claim 1, characterized in that: The sweat temperature detection paper chip is obtained by coating a ternary cholesteric liquid crystal mixture composed of cholesterol oleyl carbonate (COC), cholesterol nonanoate (CN) and 2,4-dichlorobenzoic acid cholesterol ester (CD) on a filter paper; the pH detection paper chip is obtained by dripping a pH detection reagent on a filter paper, and the pH detection reagent is a mixed solution of bromocresol purple, bromocresol green and bromothymol blue; The urea detection paper chip is obtained by dissolving p-dimethylaminobenzaldehyde in a sulfuric acid solution and then dripping it onto a filter paper; the chloride ion detection paper chip is obtained by dripping a mercuric thiocyanate ethanol solution and a Fe(NO3)3 solution onto a filter paper; the magnesium ion detection paper chip is obtained by dripping an chrome black T solution onto a filter paper; the sweat rate detection paper chip is obtained by soaking a plurality of filter papers in dyes of different colors, thereby obtaining sweat rate detection paper chips of a plurality of different colors.

5. The flexible wearable sweat multi-parameter detection microfluidic chip according to claim 1, characterized in that: The sealing layer is made of PDMS film or nano glue, PET film material; the thickness of the sealing layer is 0.2mm.

6. The flexible wearable sweat multi-parameter detection microfluidic chip according to claim 1, characterized in that: The adhesive layer is any one of an adhesive-treated PDMS film, a transparent medical double-sided tape, and a double-sided adhesive film; a plurality of injection ports are arranged on the adhesive layer; and the thickness of the adhesive layer is 0.2 mm.

7. The flexible wearable sweat multi-parameter detection microfluidic chip according to claim 1, characterized in that: The injection port on the adhesive layer corresponds to the injection hole of the PDMS flow channel layer.

8. The method for preparing the flexible wearable sweat multi-parameter detection microfluidic chip according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: loading a paper chip modified with a detection reagent into a chamber corresponding to a PDMS circulation channel layer, covering the PDMS circulation channel layer with a capping layer, placing an adhesive layer under the PDMS circulation channel layer, and encapsulating the adhesive layer after the injection port of the adhesive layer corresponds to the injection hole position of the PDMS circulation channel layer.

9. Application of the flexible wearable sweat multi-parameter detection microfluidic chip according to any one of claims 1 to 7 or the microfluidic chip prepared by the preparation method according to claim 8 in sweat multi-parameter detection.

10. The use according to claim 9, characterized in that: The following steps are involved: (1) A flexible wearable sweat multi-parameter detection microfluidic chip is attached to different parts of human skin, and sweat is produced by exercise, and the sweat flows into the chip through the sampling port of the microfluidic chip; (2) After the sweat flows through each detection chamber or small chamber of the microfluidic chip and a color reaction occurs, a color image of the microfluidic chip is obtained by taking a photo, and the RGB value of the image of each detection area is further obtained using image editing software. The concentration of various biomarkers in the sweat is calculated, the body surface temperature is read through the color information, and the sweat rate is calculated through the color bar and the detection time.

Images