A test paper for total cholesterol

Abstract

The application relates to a total cholesterol detection test paper, and belongs to the technical field of medical devices. The total cholesterol detection test paper comprises a substrate layer, an electrode layer, an insulating layer and a middle separation layer which are sequentially stacked; the insulating layer and the middle separation layer are provided with a sample inlet channel to form a test area; the electrode layer comprises a current detection working electrode and a current detection counter electrode which are arranged at intervals, and a first area of the current detection working electrode in the sample inlet channel is smaller than a second area of the current detection counter electrode in the sample inlet channel. In the application, the first area of the current detection working electrode in the sample inlet channel is smaller than the second area of the current detection counter electrode in the sample inlet channel, so that the current gradient of the total cholesterol detection signal can be improved, and the detection result is more accurate.

Description

Technical Field

[0001] This application relates to a total cholesterol test strip, belonging to the field of medical device technology. Background Technology

[0002] With the continuous improvement of living standards, the number of people with high total cholesterol is increasing. Various complications caused by high total cholesterol, such as coronary heart disease and atherosclerosis, pose a significant threat to individual health. Therefore, timely monitoring and control of total cholesterol has become a crucial means for people with high total cholesterol to maintain their health and promptly eliminate potential health risks.

[0003] Total cholesterol test strips are widely used due to their advantages such as ease of use, portability, and real-time detection capabilities. They work by acquiring the electrochemical signal generated by the reaction of total cholesterol in the test sample with the test reagent, and then using data processing equipment to convert this signal into analyte measurement data, thus enabling the detection of total cholesterol. However, the accuracy of existing total cholesterol test strips is relatively low and requires further optimization and improvement. Utility Model Content

[0004] To address the aforementioned issues, this application proposes a total cholesterol test strip. By setting the first area of ​​the current detection working electrode within the sample injection channel to be smaller than the second area of ​​the current detection counter electrode within the sample injection channel, the current gradient of the total cholesterol detection signal can be improved, resulting in more accurate detection results.

[0005] This application provides a total cholesterol test strip, comprising: A substrate layer, an electrode layer, a reagent layer, an insulating layer, and a partition layer are sequentially stacked; the insulating layer and the partition layer are provided with sample injection channels to form a test area; The electrode layer includes a current detection working electrode and a current detection counter electrode arranged at intervals. The first area of ​​the current detection working electrode located in the sample injection channel is smaller than the second area of ​​the current detection counter electrode located in the sample injection channel.

[0006] Optionally, the ratio of the first area to the second area is in the range of 0.5 to 1.0.

[0007] Optionally, the electrode layer further includes an impedance detection working electrode and an impedance detection counter electrode arranged at intervals.

[0008] Optionally, the electrode layer further includes a wire, one end of which forks to form two connecting lines, one connecting line being connected to the impedance detection electrode and the other connecting line being connected to the current detection electrode.

[0009] Optionally, the area ratio of the impedance detection working electrode to the impedance detection counter electrode is 1.0 to 1.5.

[0010] Optionally, the distance between the impedance detection working electrode and the impedance detection counter electrode is 0.6~1.0 mm.

[0011] Optionally, the distance between the current detection working electrode and the current detection counter electrode is 0.25~1.0 mm.

[0012] Optionally, the impedance detection working electrode and the impedance detection counter electrode are disposed at one end of the sample injection channel inlet, and the current detection working electrode and the current detection counter electrode are disposed at the other end of the sample injection channel inlet.

[0013] Optionally, the sample inlet channel width at the impedance detection working electrode and the impedance detection counter electrode is smaller than the sample inlet channel width at the current detection working electrode and the current detection counter electrode.

[0014] Optionally, the partition layer includes a hydrophilic membrane layer and a double-sided adhesive layer, with vent holes provided above the hydrophilic membrane layer.

[0015] Optionally, the diameter of the vent hole is 0.3~0.5mm.

[0016] Optionally, the number of vent holes is 1 to 4.

[0017] Optionally, the insulating layer has a first opening, and the double-sided adhesive layer has a second opening corresponding to the first opening, the first opening and the second opening together forming the sample inlet channel.

[0018] Optionally, the electrode layer further includes a sample injection detection electrode, which is spaced apart from the current detection working electrode and the current detection counter electrode.

[0019] Optionally, a shielding layer may also be included, wherein the electrode layer, reagent layer, insulating layer and interlayer are all located between the base layer and the shielding layer.

[0020] Optionally, it also includes a back card insulating layer and a back card silver layer, wherein the back card insulating layer is disposed on both sides of the base layer opposite to the electrode layer, and the back card silver layer is disposed on the back card insulating layer.

[0021] Optionally, the sample detection electrode is a silver electrode.

[0022] Optionally, the impedance detection working electrode, impedance detection counter electrode, current detection working electrode, and current detection counter electrode are carbon electrodes.

[0023] Optionally, the conductor is a precious metal conductor.

[0024] Optionally, the conductor is a silver conductor.

[0025] Optionally, the detection reagents in the reagent layer include one or more of cholesterol oxidase, cholesterol esterase, and horseradish peroxidase.

[0026] The beneficial effects that this application may produce include, but are not limited to: The total cholesterol test strip provided in this application comprises a base layer, an electrode layer, a reagent layer, an insulating layer, and a spacer layer stacked sequentially. The electrode layer includes a current detection working electrode and a current detection counter electrode arranged at intervals. Through experimental research, the applicant discovered that setting the first area of ​​the current detection working electrode in the sample injection channel to be smaller than the second area of ​​the current detection counter electrode in the sample injection channel can improve the electron transfer efficiency in the reaction process between total cholesterol in the test sample and the reagent layer, enhance the current gradient of the electrochemical signal for total cholesterol detection, and make the detection results more accurate. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the exploded structure of the total cholesterol test strip involved in the embodiments of this application; Figure 2 This is a schematic diagram of the electrode layer distribution of the total cholesterol test strip according to an embodiment of this application; Figure 3 This is a comparison graph of the current of samples 1 to 3 involved in this application; Figure 4 The diagram shows the impedance comparison results of samples 4 to 6 involved in this application.

[0028] List of components and reference numerals: 1-Shielding layer, 2-Intermediate layer, 3-Reagent layer, 4-Insulating layer, 5-Front carbon layer, 6-Front silver layer, 7-Base layer, 8-Back card insulating layer, 9-Back card silver layer, 10-Electrode layer, 11-Impedance detection working electrode, 12-Impedance detection counter electrode, 13-Current detection counter electrode, 14-Current detection working electrode, 15-Sample injection detection electrode, 16-Sample injection channel. Detailed Implementation

[0029] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0030] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0032] Furthermore, it should be understood in the description of this application that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0036] refer to Figures 1-2 The present application discloses a total cholesterol test strip, comprising: a base layer, an electrode layer, a reagent layer, an insulating layer and a partition layer stacked sequentially; the insulating layer and the partition layer are provided with sample injection channels to form a test area; the electrode layer includes a current detection working electrode and a current detection counter electrode arranged at intervals, wherein the first area of ​​the current detection working electrode located in the sample injection channel is smaller than the second area of ​​the current detection counter electrode located in the sample injection channel.

[0037] In this application, by setting the first area of ​​the current detection working electrode in the sample injection channel to be smaller than the second area of ​​the current detection counter electrode in the sample injection channel, that is, the area of ​​the current detection counter electrode is larger, which can improve the electron transfer efficiency in the reaction process between total cholesterol in the test sample and the reagent layer, enhance the current gradient of the electrochemical signal for total cholesterol detection, and make the detection results more accurate.

[0038] It is important to note that the current gradient is one of the core performance indicators of total cholesterol test strips. Existing test strips often suffer from insufficient current gradients, leading to "signal saturation" at high total cholesterol concentrations (meaning the current signal no longer increases with concentration) and "signal drowning" at low concentrations (meaning the current signal approaches background noise). However, an increased current gradient allows for a wider range of current information within the same concentration range, enabling accurate detection of both low and high concentrations, reducing the probability of exceeding the detection range, and improving the accuracy of test results. Furthermore, an increased current gradient reduces the proportion of background noise caused by impurities or environmental factors in the test sample, improving the test strip's anti-interference ability and sensitivity. Even minute fluctuations in total cholesterol concentration can be detected, further enhancing the accuracy of test results. Additionally, a low current gradient requires a large sample size to generate a detectable current signal, while an increased current gradient requires only a small sample to generate a clear signal, making it suitable for populations with difficult blood collection and reducing the failure rate due to insufficient sample volume.

[0039] In one implementation, the ratio of the first area to the second area ranges from 0.5 to 1.0, with specific values ​​including but not limited to 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0. When the ratio of the first area to the second area is within the above range, the current gradient of the total cholesterol detection signal is significantly increased, resulting in more accurate detection results.

[0040] In one implementation, the electrode layer also includes impedance detection working electrodes and impedance detection counter electrodes spaced apart. By setting impedance detection electrodes, the need for a blood filtration membrane to eliminate the influence of red blood cell percentage can be avoided, thereby reducing the required blood volume and shortening the detection time.

[0041] It should be noted that in the process of total cholesterol testing of blood samples, if the red blood cell percentage is too high, the sample passes through the injection channel more slowly, shortening the reaction time between the total cholesterol and the reagent layer, which may lead to incomplete reaction and a lower detection value. Conversely, if the red blood cell percentage is too low, the sample permeates too quickly, rapidly diluting the reagent layer, which also affects reaction efficiency and leads to inaccurate detection values. Therefore, it is necessary to detect the volume percentage of red blood cells in the blood sample as a calibration basis to improve the accuracy of total cholesterol test results. The red blood cell percentage can be calculated by detecting the impedance value of the blood sample.

[0042] In one implementation, the area ratio of the impedance detection working electrode to the impedance detection counter electrode is 1.0 to 1.5, and the specific values ​​include, but are not limited to, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5.

[0043] In one implementation, the electrode layer also includes a wire, one end of which branches to form two connecting lines. One connecting line is connected to the impedance detection electrode, and the other connecting line is connected to the current detection electrode.

[0044] By setting the impedance detection electrode and the current detection electrode to share a single wire, the structure of the test strip can be simplified without affecting the detection function, reducing manufacturing difficulty and production costs. Furthermore, it can avoid coupling interference between multiple wires due to excessively close proximity, resulting in a more stable detection signal.

[0045] In one implementation, the distance between the impedance detection working electrode and the impedance detection counter electrode is 0.6 mm to 1.0 mm.

[0046] In one implementation, the distance between the current sensing working electrode and the current sensing counter electrode is 0.25 mm to 1.0 mm.

[0047] In one implementation, the impedance detection working electrode and impedance detection counter electrode are located at one end of the sample injection channel inlet, while the current detection working electrode and current detection counter electrode are located at the other end of the sample injection channel inlet. Impedance detection is performed first at the start of sample injection, ensuring the accuracy of the red blood cell percentage detection.

[0048] In one implementation, the sample channel width at the impedance detection working electrode and impedance detection counter electrode is smaller than that at the current detection working electrode and current detection counter electrode. The current detection working electrode and current detection counter electrode are covered with a reagent layer, requiring a certain width to expose the detection reagents. Since impedance detection requires less blood sample than total cholesterol detection, this design reduces the required blood volume.

[0049] In one implementation, the partition layer includes a hydrophilic film layer and a double-sided adhesive layer, with the hydrophilic film layer adhered and fixed to the insulating layer using the double-sided adhesive layer. A vent is provided above the hydrophilic film layer, located above the sample inlet channel, to ensure uniform diffusion of the test sample within the sample inlet channel.

[0050] In one implementation, the diameter of the vent hole is 0.3~0.5mm.

[0051] In one implementation, the number of vents is 1 to 4.

[0052] In one embodiment, the insulating layer has a first opening, and the double-sided adhesive layer has a second opening corresponding to the first opening. The first opening and the second opening together form a sample inlet channel.

[0053] It should be noted that this application does not impose any limitations on the position of the current detection working electrode and the current detection counter electrode. Figures 1-2 For illustrative purposes only, in other examples, the test sample may pass through the current detection counter electrode and then the current detection working electrode in the injection channel.

[0054] In one implementation, the electrode layer also includes a sample injection detection electrode, which is spaced apart from the current detection working electrode and the current detection counter electrode. The sample injection detection electrode is located at the end of the sample injection channel away from the inlet, that is, the test sample passes through the area where the sample injection detection electrode is located last in the sample injection channel.

[0055] As one implementation, the total cholesterol test strip also includes a shielding layer. The electrode layer, reagent layer, insulating layer, and interlayer are all located between the base layer and the shielding layer. The shielding layer can protect the inside of the test strip from contamination and ensure the accuracy of the test results.

[0056] In one implementation method, the sample injection detection electrode is a silver electrode. Using metallic silver as the electrode material eliminates the need to add enzyme solution or increase the excitation voltage to boost the detection current signal, and also avoids the problem of low test results due to insufficient sample injection.

[0057] In one implementation, the impedance detection working electrode, impedance detection counter electrode, current detection working electrode, current detection counter electrode, and sample injection detection electrode are each configured as a carbon layer electrode and connected to corresponding wires. It should be noted that the current signals generated by the reactions on each electrode are transmitted to a data processing device via wires, where the data processing device processes these current signals to obtain the final total cholesterol detection data.

[0058] In one implementation, the conductor is a metal conductor.

[0059] In one implementation method, the conductor is a silver conductor.

[0060] In one embodiment, the total cholesterol test strip also includes a back card insulating layer and a back card silver layer. The back card insulating layer is disposed on both sides of the base layer opposite to the electrode layer, and the back card silver layer is disposed on the back card insulating layer.

[0061] It should be noted that the insulating layer and silver layer on the back card are used to provide the data processing equipment with relevant parameters of the test strip, such as test strip type, calibration parameters, sensitivity range, etc. The data processing equipment processes the acquired current signal accordingly based on the above parameters.

[0062] It should be noted that the setup of the aforementioned data processing equipment and the data processing process can be implemented using existing technologies, and will not be elaborated upon here.

[0063] In one implementation, the detection reagents in the reagent layer include one or more of cholesterol oxidase, cholesterol esterase, and peroxidase.

[0064] The technical solution of this application is illustrated below using experimental examples 1 and 2.

[0065] Experimental Example 1 like Figure 1 and Figure 2 As shown, a total cholesterol test strip sample 1 is provided, in which the area ratio of the current detection working electrode to the current detection counter electrode is 1.3, and the two are spaced 0.5 mm apart. Table 1 shows the current performance of sample 1 at different total cholesterol concentrations.

[0066] As shown in Table 1, the total cholesterol concentration (Chol) increased from 3.14 mmol / L to 10.21 mmol / L, and the average current (AV) increased from 1.3 μA to 2.4 μA. The standard deviation of current (SD) remained low, and the current gradient was 1.1 μA. When the total cholesterol concentration was high, the coefficient of variation of current (CV) was slightly higher, and the fluctuation of the test results was relatively high.

[0067] Table 1. Current performance of Sample 1 at different total cholesterol concentrations

[0068] like Figure 1 and Figure 2 As shown, a total cholesterol test strip sample 2 is provided, in which the area ratio of the current detection working electrode to the current detection counter electrode is 1.0, and the two are spaced 0.5 mm apart. Table 2 shows the current performance of sample 2 at different total cholesterol concentrations.

[0069] As can be seen from the results in Table 2, the total cholesterol concentration (Chol) increased from 3.14 mmol / L to 10.21 mmol / L, and the average current (AV) increased from 1.2 μA to 3.4 μA, with a current gradient of 2.2 μA, which is significantly higher than that of sample 1.

[0070] like Figure 1 and Figure 2 As shown, a total cholesterol test strip sample 3 is provided, in which the area ratio of the current detection working electrode to the current detection counter electrode is 0.5, and the two are spaced 0.5 mm apart. Table 3 shows the current performance of sample 3 at different total cholesterol concentrations.

[0071] Table 2. Current performance of Sample 2 at different total cholesterol concentrations

[0072] Table 3. Current performance of Sample 3 at different total cholesterol concentrations.

[0073] As shown in Table 3, the total cholesterol concentration (Chol) increased from 3.14 mmol / L to 10.21 mmol / L, and the average current (AV) increased from 1.7 μA to 4.5 μA, with a current gradient of 2.8 μA, representing a further improvement compared to sample 2. Additionally, combined with... Figure 3It can be seen that by adjusting the area ratio of the current detection working electrode and the current detection counter electrode, the current gradients of samples 2 and 3 are larger, and the corresponding current detection accuracy is also higher than that of sample 1.

[0074] Experiment Example 2 like Figure 1 and Figure 2 As shown, total cholesterol test strip sample 4 is provided, in which the area ratio of the impedance detection working electrode and the impedance detection counter electrode is 1.0, and the two are spaced 0.7 mm apart. Table 4 shows the impedance performance of sample 4 under the same total cholesterol concentration and different hematocrit (HCT) conditions.

[0075] Table 4. Impedance performance of Sample 4 under different HCT conditions

[0076] As can be seen from the results in Table 4, the HCT value increased from 30% to 60%, and the impedance gradient calculated from the average current signal AV was around 7000. The impedance was clearly distinguished under each HCT condition, and the impedance coefficient of variation CV was low, indicating high detection accuracy.

[0077] like Figure 1 and Figure 2 As shown, total cholesterol test strip sample 5 is provided, in which the area ratio of the impedance detection working electrode to the impedance detection counter electrode is 1.5, and the two are spaced 0.7 mm apart. Table 5 shows the impedance performance of sample 5 under the same total cholesterol concentration and different HCT conditions.

[0078] As can be seen from the results in Table 5, the HCT value increased from 30% to 60%, and the impedance gradient calculated from the average current signal AV was around 7700. The impedance was clearly distinguished under each HCT condition, and the impedance coefficient of variation CV was low, indicating high detection accuracy.

[0079] Table 5. Impedance performance of Sample 5 under different HCT conditions.

[0080] Table 6. Impedance performance of Sample 6 under different HCT conditions

[0081] like Figure 1 and Figure 2 As shown, a total cholesterol test strip sample 6 is provided, in which the area ratio of the impedance detection working electrode to the impedance detection counter electrode is 1.8, and the two are spaced 0.7 mm apart. Table 6 shows the impedance performance of sample 6 under the same total cholesterol concentration and different HCT conditions.

[0082] As can be seen from the results in Table 6, as the HCT value increased from 30% to 60%, the impedance gradient calculated using the average current signal AV was approximately 5500. The impedance differentiation under each HCT condition was lower compared to samples 4 and 5. Furthermore, combined with... Figure 4 It can be seen that the impedance gradients of samples 4 and 5 are relatively large, and the corresponding detection accuracy is also relatively high.

[0083] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0084] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A total cholesterol test strip, characterized in that, include: A substrate layer, an electrode layer, a reagent layer, an insulating layer, and a partition layer are sequentially stacked; the insulating layer and the partition layer are provided with sample injection channels to form a test area; The electrode layer includes a current detection working electrode and a current detection counter electrode arranged at intervals. The first area of ​​the current detection working electrode located in the sample injection channel is smaller than the second area of ​​the current detection counter electrode located in the sample injection channel.

2. The total cholesterol test strip according to claim 1, characterized in that, The ratio of the first area to the second area ranges from 0.5 to 1.

0.

3. The total cholesterol test strip according to claim 1, characterized in that, The electrode layer also includes impedance detection working electrodes and impedance detection counter electrodes arranged at intervals.

4. The total cholesterol test strip according to claim 3, characterized in that, The electrode layer also includes a wire, one end of which forks to form two connecting lines. One connecting line is connected to the impedance detection electrode, and the other connecting line is connected to the current detection electrode.

5. The total cholesterol test strip according to claim 3, characterized in that, The area ratio of the impedance detection working electrode to the impedance detection counter electrode is 1.0 to 1.

5.

6. The total cholesterol test strip according to claim 1, characterized in that, The partition layer includes a hydrophilic membrane layer and a double-sided adhesive layer, and the hydrophilic membrane layer has ventilation holes on its upper part.

7. The total cholesterol test strip according to claim 6, characterized in that, The insulating layer has a first opening, and the double-sided adhesive layer has a second opening corresponding to the first opening. The first opening and the second opening together form the sample inlet channel.

8. The total cholesterol test strip according to claim 1, characterized in that, The electrode layer also includes a sample injection detection electrode, which is spaced apart from the current detection working electrode and the current detection counter electrode.

9. The total cholesterol test strip according to claim 1, characterized in that, It also includes a shielding layer, wherein the electrode layer, reagent layer, insulating layer and intermediate layer are all located between the base layer and the shielding layer.

10. The total cholesterol test strip according to claim 1, characterized in that, It also includes a back card insulating layer and a back card silver layer, wherein the back card insulating layer is disposed on both sides of the base layer opposite to the electrode layer, and the back card silver layer is disposed on the back card insulating layer.

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