CN110836915A

CN110836915A - Non-embedded blood sugar detection system and construction method and detection method thereof

Info

Publication number: CN110836915A
Application number: CN201911142758.8A
Authority: CN
Inventors: 苗凤娟; 陶佰睿; 苗瑞; 武文逸
Original assignee: Qiqihar University
Current assignee: Qiqihar University
Priority date: 2019-11-20
Filing date: 2019-11-20
Publication date: 2020-02-25

Abstract

The invention discloses a non-embedded blood sugar detection system and a construction method and a detection method thereof, wherein the non-embedded blood sugar detection system is based on an electrochemical sensor and comprises a microcontroller module, a power supply voltage stabilization module, a digital-to-analog conversion module, a glucose sensor module, a data transmission module, a background server module, a data calibration module, a data analysis module, a liquid crystal display and a PC (personal computer) end and mobile end display module; the specific construction method comprises the steps of preparing the glucose sensor, testing the performance of the glucose sensor, designing hardware of a detection system, realizing a wireless transmission function and designing a display client. The system adopts a non-invasive detection method to judge the blood glucose concentration of the human body, can perform wireless transmission, cloud storage, real-time viewing and online analysis on data, and has an obvious auxiliary effect on the healthy life of people.

Description

Non-embedded blood sugar detection system and construction method and detection method thereof

Technical Field

The invention relates to the field of blood sugar detection systems, in particular to a non-embedded blood sugar detection system and a construction method and a detection method thereof.

Background

Diabetes is one of the most important chronic non-infectious diseases threatening the global human health at present, and according to the latest statistics of the international diabetes union, the number of the global diabetes patients reaches 3.82 hundred million, wherein the number of the national diabetes patients reaches 1.14 hundred million. The diabetes is serious in harm, and serious complications caused by the diabetes, such as diabetic nephropathy, diabetic cataract, diabetic foot and the like seriously threaten the health and life safety of patients except that the diabetes is difficult to completely cure. For diabetic patients, blood sugar control is the only effective treatment means at present, so accurate detection of blood sugar in human bodies is necessary. The traditional method for detecting the blood sugar needs to extract blood in a human body firstly and then carry out detection, so that the skin is injured, improper treatment can cause infection, and the detection flow is complicated.

Disclosure of Invention

In view of the above problems, the present invention provides a non-invasive method for determining blood glucose level of a human body by detecting saliva excreted from the human body with an electrochemical sensor with ultra-high sensitivity.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

non-embedded blood sugar detecting system, its characterized in that: the system comprises a microcontroller module, a power supply voltage stabilization module, a digital-to-analog conversion module, a glucose sensor module, a data transmission module, a background server module, a data calibration module, a data analysis module, a liquid crystal display and PC (personal computer) end and mobile end display modules;

the microcontroller module comprises a microcontroller and a minimum system circuit, wherein the minimum system circuit comprises a download filter circuit and a reset circuit; the download filter circuit adopts capacitor filtering to obtain a voltage signal with a stable waveform; the download filter circuit and the reset circuit realize the burning of the program of the micro-controller and the reset restart of the whole system; the microcontroller completes normal operation and control work of the whole system;

the power supply voltage stabilizing module realizes the functions of power supply voltage transformation and voltage stabilization;

the digital-to-analog conversion module realizes a digital-to-analog conversion function and is connected with the microcontroller module;

the glucose sensor module converts the change of the glucose concentration in the solution into the change of voltage and feeds the change of voltage back to the microcontroller module for processing and analysis;

the data transmission module realizes wireless data transmission;

the background server module analyzes the uploaded data, then stores the data into a database, and waits for the calling of the client;

the data calibration module calibrates data;

the data analysis module analyzes and processes the trend and the trend of the data;

the liquid crystal screen display and PC end and mobile end display module displays the data which are calibrated and analyzed;

the microcontroller module controls the digital-to-analog conversion module to output triangular wave voltage to act on the glucose sensor module; the glucose sensor module feeds the measured voltage value back to the microcontroller module, the microcontroller module displays the measured voltage value on a liquid crystal display screen, and the data transmission module is used for transmitting data to the background server module through a wireless transmission technology; the data calibration module performs software calibration on the tested data; the data analysis module calls data of nearly seven tests in the memory for data trend analysis; and finally, displaying the data result after processing and analysis on a PC (personal computer) end and a mobile end display module.

Further, the glucose sensor module comprises a three-electrode measurement system, and the three electrodes are respectively a reference electrode, a counter electrode and a working electrode.

Further, the working electrode is a Pd-G-ZnO/NiF electrode.

Further, the construction method of the non-embedded blood sugar detection system is characterized by comprising the following steps:

s1: preparing a glucose sensor;

s2: testing the performance of the glucose sensor;

s3: detecting system hardware design;

s4: realizing a wireless transmission function;

s5: and displaying the design of the client.

Further, the specific operation of step S1 includes:

s11: cutting the NiF plate into NiF sheets, cleaning and drying;

s12: taking a copper wire as a lead at one corner of the treated NiF sheet, coating silver paste on the joint, and drying in a drying oven; completely isolating the copper wire and the silver paste by using epoxy resin, and drying after sealing glue each time;

s13: dispersing ZnO in ethanol and carrying out ultrasonic treatment to obtain a solution A; dispersing graphene into ethanol for ultrasonic treatment to form a solution B;

s14: dropwise adding the solution A into the solution B under the stirring condition, and performing ultrasonic treatment at room temperature for more than 20min to obtain a graphene/zinc oxide mixed solution;

s15: covering the mixed solution on the NiF sheet processed in the step S13 by a dripping method, and drying to obtain a G-ZnO/NiF electrode;

s16: weighing quantitative NH₄Dissolving Cl and ethylene diamine tetraacetic acid in the aqueous solution, fixing the volume of the solution, magnetically stirring for 20min, and performing ultrasonic treatment for 10min to obtain a plating solution;

s17: dropwise adding ammonia water into the plating solution to adjust the pH value of the solution until the pH value is increased to 8-8.5;

s18: weighing quantitative PdCl2 powder, adding into the plating solution, and ultrasonically mixing until the solution becomes bright yellow transparent liquid;

s19: and assembling the prepared G-ZnO/NiF electrode and a platinum electrode to obtain the glucose sensor.

Further, the performance test of the glucose sensor in the step S2 includes a characterization test and an electrochemical test; the characterization test comprises scanning electron microscope characterization, X-ray diffraction characterization, X-ray photoelectron characterization and determination of electrode surface area; the electrochemical test includes tests for sensitivity, selectivity, and stability of the glucose sensor.

Further, step S3 adopts embedded technology to design the hardware of the detection system.

Further, the detection method of the non-embedded blood sugar detection system is characterized by comprising the following steps:

s1: debugging a blood sugar detection system to ensure that the blood sugar detection system can be normally used;

s2: collecting saliva of a human body in a clean container, and placing the saliva in a beaker;

s3: diluting with KOH solution in saliva sample;

s4: measuring the diluted solution by using a non-embedded blood sugar detection system;

s5: the peak voltage obtained by the test of the non-embedded blood sugar detection system is displayed on the liquid crystal screen;

s6: the result of the data calibration data analysis is displayed on the PC terminal and the mobile terminal display module for the user to check.

The invention has the beneficial effects that:

1. the core technology in the blood sugar detection system is a glucose electrochemical sensor, and the sensitivity of the Pd-G-ZnO/NiF electrode to glucose is utilized, so that the blood sugar detection system has high detection precision and good selectivity.

2. The blood sugar detection system of the invention utilizes the embedded technology to simulate a large-scale electrochemical workstation to carry out CV test, realizes the miniaturization of equipment, reduces the equipment cost, simplifies the complexity of operation, has simple operation and small volume, and can be carried conveniently;

3. the blood sugar detection system can realize wireless transmission, cloud storage, real-time viewing and online analysis of data, can monitor the blood sugar change condition of a human body in real time, and has an obvious auxiliary effect on the healthy life of people.

Drawings

FIG. 1 is a CV diagram of the reaction of an electrode of the present invention with glucose;

FIG. 2a is a CV diagram of a Pd-G-ZnO/NiF electrode with 1, 2, 3, 10, 20, 30mM glucose added to a 0.1M/L KOH solution according to the present invention;

FIG. 2b is the CV diagram of the Pd-G-ZnO/NiF glucose electrode with 0.1, 0.3, 0.4, 0.5, 0.8, 1.0M added to the KOH solution of 1M/L of the present invention;

FIG. 3 is a circuit logic and functional block diagram of the non-embedded blood glucose detecting system based on electrochemical sensor according to the present invention;

FIG. 4 is a logic diagram of an analog electrochemical workstation of the non-embedded blood glucose monitoring system based on electrochemical sensors according to the present invention;

FIG. 5 is a flow chart of a method for constructing a non-embedded blood glucose monitoring system based on an electrochemical sensor according to the present invention;

FIG. 6 is a schematic view of the fabrication process of the ZnO/NiF electrode of the present invention;

FIG. 7 is a schematic view of the manufacturing process of Pd-G-ZnO/NiF electrode plating according to the present invention;

FIG. 8 is an SEM image of the surface morphology of the Pd-G-ZnO/NiF electrode of the invention;

FIG. 9a is an XRD spectrum of a G-ZnO/NiF electrode of the present invention;

FIG. 9b is an XRD spectrum of a Pd-G-ZnO/NiF electrode of the present invention;

FIG. 10a is an XPS spectrum of a Pd-G-ZnO/NiF electrode of the present invention;

FIG. 10b is an XPS spectrum of a Ni peak of the invention;

FIG. 10c is an XPS spectrum of Pd according to the invention;

FIG. 10d is an XPS spectrum of ZnO of the present invention;

fig. 10e is an XPS spectrum of graphene of the present invention;

FIG. 11 is a graph showing the results of nitrogen adsorption testing of the Pd-G-ZnO/NiF electrode of the present invention;

FIG. 12a is a graph showing the current-time response of a Pd-G-ZnO/NiF electrode in the present invention with continuous addition of glucose to a 0.1M KOH solution at 0.3mM each time over the concentration range of 0 to 6 mM;

FIG. 12b is a graph showing the current-time response of a Pd-G-ZnO/NiF electrode in the present invention with continuous addition of glucose to a 0.1M KOH solution at 50. mu.M each time in the concentration range of 5 to 250. mu.M;

FIG. 13 is a graph of current versus time for a Pd-G-ZnO/NiF electrode of the present invention with the continuous addition of 1mM glucose, 1mM DA, 1mM AA, 1mM UA, 1mM fructose, 1mM D (+) -sucrose, 1mM lactose, 1mM glucose and 1mM glucose at 0.1M KOH, 0.2V;

FIG. 14a is a graph showing the results of 30 CV tests in 0.1M KOH (containing 20mM glucose) for a Pd-G-ZnO/NiF electrode according to the present invention;

FIG. 14b is a graph showing the results of 30 CV tests in 1M KOH (containing 0.5M glucose) for a Pd-G-ZnO/NiF electrode according to the present invention;

FIG. 14c is a graph showing the 1000s amperometric response of the Pd-G-ZnO/NiF electrode of the present invention at 0.2V in 1M KOH +0.5M glucose;

FIG. 14d is a graph showing the 1000s amperometric response of the Pd-G-ZnO/NiF electrode of the present invention at 0.2V in 0.1M KOH +20M glucose;

FIG. 15 is a flow chart of the detection system hardware design in accordance with the present invention;

FIG. 16 is a flow chart of the design of the connection platform in the wireless transmission function according to the present invention;

FIG. 17 is a flow chart of NB-IoT transmission process in a wireless transmission function according to the present invention;

FIG. 18 is a flow chart of the PC side application display design of the present invention;

FIG. 19 is a flow chart of the mobile-side application display design of the present invention;

FIG. 20 is a graph of a fit of a correlation between measured glucose concentration and current response according to one embodiment of the present invention;

FIG. 21 is a histogram of peak current response in a second embodiment of the present invention;

FIG. 22 is a histogram of peak current response in the third embodiment of the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following further describes the technical solution of the present invention with reference to the drawings and the embodiments.

As shown in fig. 3 and fig. 4, the non-embedded blood sugar detecting system includes a microcontroller module, a power supply voltage stabilizing module, a digital-to-analog conversion module, a glucose sensor module, a data transmission module, a background server module, a data calibration module, a data analysis module, a liquid crystal display, and a PC end and mobile end display module;

the microcontroller module comprises a microcontroller circuit and a minimum system circuit, wherein the minimum system circuit comprises a download filter circuit and a reset circuit; the filter circuit adopts capacitance filtering to obtain a voltage signal with a stable waveform. The download filter circuit and the reset circuit have the main functions of realizing the burning of the program of the micro-controller and the reset restart of the whole system. The microcontroller Circuit (CPU) mainly completes the normal operation and control work of the whole system.

The power supply voltage stabilizing module mainly achieves the functions of voltage transformation and voltage stabilization of power supply, and because the power supply of most components in a hardware circuit needs 3.3V, 5V voltage provided by a USB is converted into needed 3.3V voltage through a voltage stabilizing chip AMS 1117.

The digital-to-analog conversion module mainly realizes the digital-to-analog conversion function. The digital signal can be converted into an analog signal or the analog signal can be converted into a digital signal by the digital-to-analog conversion module. By controlling the TLV5638 using the SPI function in the microcontroller, the driver program control of the microcontroller is changed to generate the required linear triangular wave voltage.

The glucose sensor module mainly realizes that the change of the concentration of glucose in a solution is converted into the change of voltage, and the change of voltage is fed back to the microcontroller for processing and analysis.

The data transmission module mainly utilizes a BC95 module in NB-IoT technology to realize the function of data wireless transmission. Firstly, after the BC-95 module is successfully connected with the platform, the BC95 module sends data to the platform in a framing mode of sending a data packet, a micro controller establishes a sending task by using a COAP protocol, and the data packet is uploaded to a server for storage through an IOT core network and a cloud platform.

And the background server module analyzes the uploaded data and analyzes the data packet according to the same rule to obtain the measured data. And storing the data in a MySql database, and waiting for the calling of the client.

The data calibration module further calibrates the test result to enable the data to be more accurate and error-free; the implementation method comprises the steps of repeatedly taking values of the peak current three times in the test process, and then carrying out average value calculation on the three measured peak values through a software programming method to obtain more stable and accurate peak current value data and better determine the content of glucose;

the data analysis module is used for analyzing and processing the test result of the data. The test values of the fifth time are subjected to curve drawing through a software programming method, a curve graph is displayed at a PC end or a mobile end, the trend of the test result is displayed, and the test result and the trend are displayed more clearly and clearly;

the liquid crystal display module and the PC end and mobile end display module have the main functions of displaying detected data, drawing and displaying an I-V curve in real time through the application of the PC end and the mobile end, carrying out preliminary analysis on the data in application, and reflecting the change trend of the glucose concentration by using the change of peak current.

The minimum system circuit is directly connected with a microcontroller (CPU) so that the microcontroller can normally operate. The power supply voltage stabilizing module is directly connected with the VCC of the microcontroller to supply power to the whole system. An I/O digital port in the microcontroller is connected with the digital-to-analog conversion module and outputs the required triangular wave linear scanning voltage. The digital-to-analog conversion module is connected with the constant potential measuring circuit, scanning voltage is input into the constant potential measuring circuit in the microcontroller module, the constant potential circuit applies the voltage to the sensor electrode, and a generated current signal is converted into a voltage value through trans-resistance amplification and I/V conversion. And the voltage value is transmitted to a high-precision ADC (analog to digital converter) of the microcontroller through the constant potential measuring circuit for digital-to-analog conversion. And finally, carrying out data framing on the voltage value to wait for the data transmission module to transmit, and displaying the converted voltage value on a liquid crystal display screen. And the detected voltage value is transmitted to a background server through a data transmission module, the data is calibrated through a data calibration module, and the trend of the data is analyzed and processed through a data analysis module. And finally, displaying the data after calibration and analysis on the PC side and the mobile side.

Specifically, because the Pd-G-ZnO/NiF electrode has good sensitivity to glucose, the invention combines the electrochemical sensor technology with blood glucose detection. The blood glucose concentration of a human body is judged by detecting saliva excreted by the human body by utilizing the high sensitivity, low detection limit and anti-interference capability of the electrochemical sensor to glucose; and compared with a biological enzyme sensor, the electrochemical sensor is more convenient to store, can be reused and has relatively stable precision.

Furthermore, the glucose sensor module utilizes the sensitivity of the Pd-G-ZnO/NiF electrode to glucose. When a voltage excitation source is added into the Pd-G-ZnO/NiF electrode, glucose and the electrode generate an oxidation-reduction reaction, and the oxidation-reduction peak value of the electrode is increased. As shown in FIG. 1 (see FIG. 1 of the substantive review references), the solid line in the inset is the experimental result in a blank background solution. The short dashed line is the CVs response of the Pd-G-ZnO/NiF electrode after addition of 0.5M glucose, and the comparison shows a large change. On the forward scan, a very distinct anodic peak was observed at 0.742V, when glucose was directly oxidized to form intermediates, resulting from the synergistic oxidation of glucose among the various electrocatalysts. One of the main reasons is the oxidation of glucose by PdNPs, which electrically adsorb glucose and then release a proton to form intermediates, such as Pd + glucose → Pd-H + intermediates.

As the intermediates accumulate on the surface of Pd-G-ZnO/NiF, the intermediates gradually occupy the active sites of the electrocatalyst, resulting in a decrease in peak current. Meanwhile, in the alkaline solution, Pd (OH) x species continue to adsorb partial OH along with the gradual positive shift of the potential^-The valence of Pd is continuously increased, and the formula shows that Pd + xOH^-→PdOHx+xe^-。

In the negative scanning, an oxidation peak appears at the potential of-0.23V, the current is increased sharply, the oxidized PdNPs are reduced at-0.2V, the active sites are updated, and the glucose is oxidized continuously, such as the formula PdOHx + intermediates → Pd + glucolactone or gluconic acid. Meanwhile, the intermediate is further oxidized into gluconic acid PdOHx + glucose → Pd + glucolactone or gluconic acid.

In addition, the NiF substrate is oxidized by glucosePlays an important role in the process. In the vicinity of 0.8V, NiF oxidizes glucose to gluconic acid, as in the formula Ni +2OH^-→Ni (OH)₂+2e^-；Ni(OH)₂+OH^-→NiOOH+H₂O+e-；NiOOH+glucose →Ni(OH)₂+ glucolactone; meanwhile, in an alkaline solution, ZnO has a catalytic oxidation effect on glucose. Glucose + O₂+H₂O gluconic acid+H₂O₂，H₂O₂→ O₂+2H⁺+2e^-。

As shown in FIG. 2a (see FIG. 2a of the parenchymal examination reference), CV tests were performed by adding 1, 2, 3, 10, 20, 30mM glucose in 0.1M/L KOH solution at a scan rate of 50mVs-1 as shown in FIG. 2a (see FIG. 2a of the parenchymal examination reference). When the glucose concentration increases, the oxidation peak current increases with a concomitant increase in oxidation peak potential. The increase in peak current can be attributed to the fact that as the glucose concentration increases, more glucose participates in the reaction through a diffusion effect. The inset shows the correlation of glucose concentration with the oxidation peak current density of the Pd-G-ZnO/NiF electrode, R₂A good linear relationship is demonstrated at 0.904.

On the other hand, as shown in FIG. 2b (see FIG. 2b in the parentage reference), CV curves of Pd-G-ZnO/NiF glucose electrodes at a scan rate of 50mV s-1 were added at 1M/LKOH at 0.1, 0.3, 0.4, 0.5, 0.8, 1.0M. It can be observed that the peak potential shifts positively and the peak current increases with increasing glucose concentration. However, when the glucose concentration exceeds 0.5M/L, the oxidation peak current decreases due to the following reasons: first, the electrode surface is saturated with active sites and does not provide more active sites for glucose oxidation, thereby accelerating oxidation. Secondly, the intermediate product may cover and poison the active species on the electrode surface, reducing its catalytic activity. Finally, the higher the glucose concentration, the higher the solution viscosity, the poorer the mass transfer effect, and the lower the mass transfer rate. Analysis can clearly show that the concentration of the glucose has a good linear relation with the CV redox peak value, and the concentration of the glucose can be well reflected by the CV redox peak value, so that the concentration of the glucose in the solution can be detected.

Further, the invention also uses a narrowband Internet of things (NB-IoT) wireless transmission technology in the system. The narrow-band Internet of things (NB-IoT) wireless transmission technology can transmit the results detected by the electrochemical sensor to a background human-computer interaction interface in real time, so that a detector can quickly and intuitively see the detection analysis results.

Furthermore, the invention also utilizes the embedded technology to simulate a large-scale electrochemical workstation to carry out CV test, realizes the miniaturization of equipment, reduces the equipment cost, simplifies the complexity of operation and is more convenient for the use and popularization of the system.

Furthermore, the data and signaling exchange between the sensor and the cloud server is completed through the IoT cloud platform, and the Visual Studio and the Android Studio are respectively used for designing PC end software and smart phone application to graphically display the data, so that the functions of real-time data viewing and online data analysis through the terminal by a user are realized.

Preferably, the microcontroller module adopts an STM32 microcontroller;

preferably, the data transmission module adopts BC95 data transmission;

the BC95 data transmission module realizes a data wireless transmission function by utilizing NB-IoT technology, firstly, after the BC-95 module is successfully connected with a platform, the BC95 module sends data to the platform in a framing mode of sending a data packet by utilizing a CoAP protocol, the MCU controls and establishes a sending task, and the data packet is uploaded to a background server for storage through an IOT core network and a cloud platform. And analyzing the uploaded data, and analyzing the data packet according to the same rule to obtain measured data. And uploading the data to an IoT platform, connecting the platform with a background server, storing the data to a MySql database, and waiting for the call of a client.

Further, as shown in fig. 5, the method for constructing the non-embedded blood sugar test system comprises the following steps:

s1: preparing a glucose sensor;

s2: testing the performance of the glucose sensor;

s3: detecting system hardware design;

s4: realizing a wireless transmission function;

s5: and displaying the design of the client.

Specifically, firstly, a sensor electrode with a micro-nano structure is prepared, and the performance of the electrode is tested to obtain the electrochemical sensor meeting the design requirement. Secondly, a portable sensor system is further designed through an embedded technology, and a microcontroller is used for simulating a glucose test method of an electrochemical workstation, so that the miniaturization of the system is realized. And then, a wireless data transmission function is realized through an NB-IoT technology, and the south equipment and the north application server of the platform are developed around the OceanConnect Internet of things cloud platform. And finally, designing client applications on the smart phone and the PC respectively to carry out graphical display on the uploaded data through the software design of the terminal display client, and realizing real-time viewing and online analysis of the data.

Further, as shown in FIGS. 6 to 7, the specific operation of the glucose sensor preparation in step S1 is,

s11: cutting NiF plate into 1cm²Ultrasonically cleaning a NiF sheet with the size of 5min in deionized water to remove water-soluble impurities; ultrasonically cleaning in acetone for 10min to remove liposoluble impurities; and then ultrasonically cleaning the sample in deionized water for 5min, ultrasonically cleaning the sample in 2mol/L diluted hydrochloric acid for 10min to remove oxides, and then washing residual reagents by using a large amount of deionized water. And drying the treated NiF sheet in a closed drying box at 60 ℃ for 30 min.

S12: the treated NiF uses a copper wire as a lead at one corner, and a proper amount of silver paste is smeared at the joint to enhance the conductivity; drying in a 60 deg.C drying oven for 30 min. Then, the copper wire and the silver paste are completely isolated by epoxy resin, and in order to prevent large-area diffusion, a small amount of glue is applied for multiple times, drying is carried out at 60 ℃ after each time of glue sealing, and 6 times of glue sealing are carried out at intervals of 30 min.

S13: dispersing 0.05g ZnO in 50ml ethanol, and subjecting to ultrasonic treatment for 10min to obtain solution A (concentration of 1 g/L)^-1). Dispersing 1g of graphene into 50ml of ethanol, and carrying out ultrasonic treatment for 30min to form a solution B.

S14: under the condition of stirring, 1 ml of A is dropwise added into 5 ml of solution B, and ultrasonic treatment is carried out at room temperature for more than 20min to obtain a graphene/zinc oxide (G-ZnO) mixed solution.

S15: and covering the mixed solution on the cleaned NiF by a dripping method, wherein the G-ZnO mixed solution is required to be excessively saturated and completely soaked on the NiF. And finally, drying at 60 ℃ for 2h to obtain the G-ZnO/NiF electrode. As shown in fig. 6.

S16: weighing quantitative NH4Cl and EDTA, dissolving in water solution to constant volume, magnetically stirring for 20min, and performing ultrasonic treatment for 10min to obtain mixed suspension, i.e. plating solution.

S17: and dropwise adding ammonia water into the plating solution to adjust the pH value of the solution until the pH value is increased to about 8-8.5. The phenomenon observed at this time was that the suspension became clear and the substance in the solution was mostly dissolved.

S18: weighing a certain amount of PdCl2 powder, adding the powder into the plating solution, and carrying out ultrasonic mixing until the solution becomes bright yellow transparent liquid.

S19: the prepared G-ZnO/NiF electrodes are connected according to the device diagram of the electroplating instrument shown in the attached figure 7, the G-ZnO/NiF electrodes are connected to a cathode as working electrodes, a platinum electrode is used as an anode, a programmable direct current power supply is set to be in a constant current mode, the current density is 10mAcm < -2 >, and the electroplating time is 30 minutes.

And further, carrying out performance test on the prepared Pd-G-ZnO/NiF electrode.

Specifically, the prepared Pd-G-ZnO/NiF electrode is subjected to characterization test.

Specifically, the prepared Pd-G-ZnO/NiF electrode is detected by a scanning electron microscope. The SEM morphology of the Pd-G-ZnO/NiF electrode is shown in FIG. 8 (see FIG. 8 in the parenchymal examination reference).

In FIG. 8a (see FIG. 8a of the substantive review reference), the Pd-G-ZnO/NiF electrode surface is magnified 300 times, and the SEM image of pure NiF is shown in the inset, and the comparison between the two shows that the original smooth nickel foam surface is obviously covered with layer-like wrinkles and burred protrusions.

The SEM image of the Pd-G-ZnO/NiF electrode after further magnification to 1500 times is shown in FIG. 8b (refer to FIG. 8b in the substantive examination reference), which clearly shows the sheet structure of graphene, and the inset shows pure nano-ZnO.

FIG. 8c (see FIG. 8c of the substantive review reference) is a 3000-fold magnification of the surface of the Pd-G-ZnO/NiF electrode, and it can be observed that both the G-ZnO surface and the NiF surface are deposited with palladium nanoparticles (PdNPs).

FIG. 8d (see FIG. 8d of the parenchymal examination reference) is an enlargement of the edge portion of the surface of the Pd-G-ZnO/NiF electrode, and it can be observed that dendritic PdNPs pillars are grown due to electrodeposition unevenness.

Fig. 8e (see fig. 8e of the substantive review reference) is a 5000-fold magnification of the counter electrode surface, and the layered structure of graphene, the agglomeration of zinc oxide, and the growth of both Pd particles and dendrites can be seen clearly.

FIG. 8f (see FIG. 8f of the parenchymal review references) is an enlargement of the dendrites PdNPs. The result shows that the change of the morphology leads the specific surface area of the original electrode to be greatly increased, and the PdNPs are successfully deposited on the surface of the electrode and grow in two forms of granular and dendritic shapes.

Further, the prepared Pd-G-ZnO/NiF electrode was subjected to X-ray diffraction (XRD) and the results are shown in FIG. 9a (see FIG. 9a in the parenchymal examination reference) and FIG. 9b (see FIG. 9b in the parenchymal examination reference).

XRD characterization is carried out on the G-ZnO/NiF electrode and the Pd-G-ZnO/NiF electrode, and the phases of the surfaces of the samples are analyzed. The XRD pattern of G-ZnO/NiF is shown in FIG. 9a (refer to FIG. 9a in the physical examination reference), and the matching of a standard PDF card (JCPDS 00-033-0214) is performed. It can be seen that the major phases of the electrode surface consist of Ni and ZnO. The XRD pattern showed three peaks associated with Ni. Around 44.5 °, 51.9 ° and 76.4 °, respectively. The diffraction peaks of ZnO are located at 2 θ of 31.7 °, 34.4 °, 36.2 °, 47.5 °, 56.7 °, 62.8 ° and 67.9 °, respectively, corresponding to the ZnO (100), (002), (101), (102), (110), (103) and (112) planes. This study showed that the formation of ZnO nanostructures was pure phase and no other crystalline phase was observed.

FIG. 9b (see FIG. 9b of the substantive examination reference) shows XRD analysis of the prepared Pd-G-ZnO/NiF electrode. It can be seen that the diffraction peaks attributed to Pd are located at 2 θ ═ 40.2 °, 46.5 °, 68.1 ° and 82.2 °, respectively, and are attributed to the (111), (200), (220) and (311) crystal plane diffraction peaks, respectively. In addition, the NiF substrate exhibits main characteristic peaks at 44.5 °, 51.8 ° and 76.4 ° 2 θ: (111) the (200) and (220). The results further confirm that PdNPs were successfully electrodeposited on NiF. ZnO-G is loaded on NiF and covered by high-density Pd nano-particles, and the diffraction peak is not obvious.

In order to find the diffraction peak of ZnO, its XRD pattern (2. theta. at 30 to 38) was further enlarged in the inset of FIG. 9b (see FIG. 9b of the substantive examination reference). Partial diffraction peaks appearing on the (100), (002) and (101) planes of the hexagonal wurtzite structure of ZnO were observed at 2 θ of 31.7 °, 34.4 ° and 36.2 °. The experimental result proves that the nano ZnO and PdNPs are successfully assembled on the surface of the electrode; the peak of graphene does not appear, possibly because the sample has a small amount of graphene, or the graphene is better dispersed without agglomeration, and another explanation is that the graphene is higher in exfoliation degree and better in quality, and cannot easily form a diffraction peak of the graphene at about 2 θ ═ 20 °.

Further, the prepared Pd-G-ZnO/NiF electrode is subjected to X-ray photoelectron spectroscopy detection, and the results are shown in the attached figures 10a-10 e.

As can be seen from FIG. 10a, Pd-G-ZnO/NiF contains Pd, Zn, O and C, but the response signal of Ni in Pd-G-ZnO/NiF is not obvious, probably because the Pd-G-ZnO nanocomposite covers NiF as a substrate, and the XPS has a scanning depth of about 5-10nm, and there may be a case that NiF is not scanned. The presence of the O element therein is attributed to the O element contained in ZnO or surface oxidation and oxygen adsorption caused when it comes into contact with air. The diffraction peaks for Ni2p 3/2 and Ni2p 1/2 were at 856.08eV and 872.58eV, respectively, as shown in FIG. 10 b.

Notably, in the Ni2p region, there are some additional satellite peaks around the expected Ni2p 3/2 and Ni2p 1/2 signal peaks. The high resolution magnified map of Pd3d showed two peaks associated with the Pd3d 5/2 and Pd3d 3/2 spin orbital states as shown in FIG. 10 c.

For the Pd-G-ZnO/NiF electrode, the strong signals shown at 335.78eV and 340.98eV correspond to Pd 0. The peak signal of Pd3d corresponds to the binding energy of Pd, and further supports the conclusion that PdNPs are effectively deposited on the surface of the G-ZnO-NiF electrode.

As shown in fig. 10d, XPS spectra of the corresponding Zn2p3 peaks for nano ZnO were at 1021.58eV and 1045.68eV, respectively, and the appearance of Zn2p3 peaks indicates that ZnO was successfully loaded on the NiF substrate surface.

As shown in fig. 10e (see fig. 10e in parenchymal review reference), in XPS spectra of graphene, a peak fit was made to the entire C peak, with three component peaks at 284.7eV, 285.8eV, and 287.8eV, respectively, corresponding to C-C, C-O and C ═ O bonds, respectively. The C-O and C ═ O components occupy a smaller proportion, confirming that the content of oxygen-containing groups in graphene is smaller and that graphene is not converted into graphene oxide.

Further, the surface area of the prepared Pd-G-ZnO/NiF electrode was measured by the Brunauer Emmett Teller (BET) method. At the liquid nitrogen temperature, the adsorption amount of nitrogen on the solid surface depends on the relative pressure of nitrogen (P/P0), P is the partial pressure of nitrogen, and P0 is the saturated vapor pressure of nitrogen at the liquid nitrogen temperature.

The mesoporous nitrogen adsorption test used herein is shown in FIG. 11 (see FIG. 11 of the substantive review references). The non-limiting adsorption of high P/P0 exhibited by the Pd-G-ZnO/NiF electrode exhibited a type IV hysteresis curve characteristic. The result shows that the specific surface area of the clean NF is 0.212m 2G 1, the specific surface area of the Pd-G-ZnO/NiF electrode is 0.974m 2G 1 which is 4.6 times that of the pure NiF, and the specific surface area of the Pd-G-ZnO/NiF is obviously improved relative to that of the pure NiF.

Further, the prepared Pd-G-ZnO/NiF electrode is subjected to electrochemical test.

In particular, the prepared Pd-G-ZnO/NiF electrode is sensitively tested.

And testing the application potential of the Pd-G-ZnO/NiF electrode as a sensitive electrode of the current type glucose sensor by using a chronoamperometry. Concentration step experiments under a chronoamperometric method are carried out on the Pd-G-ZnO/NiF electrode, namely under a fixed potential, the continuously increased glucose concentration is measured, and the continuous current response of the Pd-G-ZnO/NiF electrode in 0.1M/L KOH is measured. And (3) carrying out sensitivity analysis on the Pd-G-ZnO/NiF electrode in two concentration ranges respectively. The Pd-G-ZnO/NiF electrode has a peak potential of glucose oxidation between 0.05V and 0.2V in 0.1M KOH/L solution, i.e., the reaction of glucose oxidation occurs here, and the potential shifts to the right with increasing concentration, so 0.2V is set to a fixed potential.

FIGS. 12a (see FIG. 12a in the substantive review reference) and 12b (see FIG. 12b in the substantive review reference) are typical current-time responses of Pd-G-ZnO/NiF electrodes in glucose solutions.

FIG. 12a (see FIG. 12a for substantive review) shows a typical current-time response of a Pd-G-ZnO/NiF electrode in solutions with successively increasing glucose concentrations to 0.1M KOH solution, with an operating potential of 0.2V, with 0.3mM glucose added each time, with glucose concentrations ranging from 0 to 6 mM. The oxidation current increases linearly with the addition of glucose, exhibiting a step-like current response, and the corresponding correlation is shown in the inset of fig. 12 a. The regression equation is I (μ a) ═ 229.21+129.44C (μ M), and the correlation coefficient is 0.98. It can be seen that there is a good linear relationship between the response current and the glucose concentration. The sensitivity of the electrode under the condition is 129.44 mu AmM-1cm-2, and the electrode has good linearity in the range of 0-6 mM. The lowest detection limit was calculated to be 0.288M (S/N-3).

To further explore the amperometric response of the Pd-G-ZnO/NiF electrode at lower glucose concentrations, the amount per glucose addition was reduced from 3mM to 5. mu.M with a concentration change in the range of 0-250. mu.M, and the results are shown in FIG. 12b (see FIG. 12b of the censorship reference). The step-like current response is still significant. The regression equation is that I (μ a) ═ 62.6+2133C (μ M), and R2 ═ 0.98949. The sensitivity to glucose concentration was 213.3. mu. AmM-1 cm-2. Comparing two experiments, the amperometric response of the Pd-G-ZnO/NiF at low concentration has higher sensitivity.

Furthermore, the prepared Pd-G-ZnO/NiF electrode is subjected to a selectivity test.

Selectivity is also an important criterion for the evaluation of sensor performance, so we have designed an interference test, adding several interfering substances to the solution: ascorbic Acid (AA), Dopamine (DA), Uric Acid (UA), Sucrose (fructose), fructose (D (+) -Sucrose), lactose (lactose). AA. DA and UA appear in the blood circulation of human body, and others are similar to glucose. The experiment was carried out by chronoamperometry by adding 1mM glucose, 1mM DA, 1mM MAA, 1mM UA 1mM fructose, 1mM sucrose, 1mM lactose, 1mM glucose and 1mM glucose in succession to 0.1M/LKOH, and observing the current response, the results are shown in FIG. 13.

The result shows that the content of the interference substance in the blood is one tenth of that of the glucose, and the electrode has no obvious response to the addition of the interference substance, so that the Pd-G-ZnO/NiF electrode has good selectivity and can be used as an application scene of blood glucose detection.

Further, the prepared Pd-G-ZnO/NiF electrode is subjected to stability test.

The Pd-G-ZnO/NiF electrode was subjected to 30 cyclic voltammetry tests under two conditions of 0.1MKOH +20mM glucose and 1MKOH +0.5M glucose to examine the stability of the electrode, and the corresponding results are shown in FIGS. 14a (refer to FIG. 14a in the parentage reference materials) and 14b (refer to FIG. 14b in the parentage reference materials), respectively. The peak current of the Pd-G-ZnO/NiF electrode as a function of increasing cycle number is shown in the inset as a bar graph.

In fig. 14a (see fig. 14a for substantive review reference), the CV curve did not change significantly, and the peak current remained 98.2% after 30 scans. The result shows that the Pd-G-ZnO/NiF electrode has good stability in the electrolyte environment of 0.1M KOH +20mM glucose.

In FIG. 14b (see FIG. 14b of the parenchymal examination reference), the peak current increases with the number of cycles in the first three periods due to the large electrolyte concentration, high solution viscosity, low mass transfer efficiency, and the time required for glucose to fully penetrate the electrode surface. In the fourth cycle, the peak current reached a maximum of 179.6 mA. Subsequently, the peak current gradually decreased with successive scans, and finally remained 87.15% of the maximum after 30 cycles. The result shows that the Pd-G-ZnO/NiF electrode also has good stability. The loss of catalytic activity at the electrode in the glucose oxidation reaction can be explained by the mechanism of poisoning by intermediate species.

Chronoamperometry test Pd-G-ZnO/NiF for 1000s Ampere response in 1M KOH +0.5M glucose and 0.1M KOH +20mM glucose electrolytes as shown in FIG. 14c (see FIG. 14c in the parentage reference) and FIG. 14d (see FIG. 14d in the parentage reference). The current response did not drop significantly after 1000s of redox reaction. The result shows that the Pd-G-ZnO/NiF has good stability for glucose sensing.

Further, the design specific operation of the system hardware detected in step S3 is:

as shown in fig. 15, first, a microcontroller and a minimum system circuit are built, so that the microcontroller can perform overall control of the system. And secondly, a power supply circuit is set up to supply power to the microcontroller, the minimum system and the whole system. And then the display circuit is connected to the I/O port of the microcontroller to display the detected data. Then, data conversion is carried out through a digital-to-analog conversion module, and triangular waves are output through the control of a microcontroller to excite the glucose sensor. And finally, detecting the voltage generated by the glucose sensor through the constant potential acquisition circuit, transmitting the voltage through the I/O port, and transmitting data to the microcontroller.

Further, the implementation of the wireless transmission function in step S4 is implemented by:

the flow of the wireless transmission function and the connection platform is shown in fig. 16. Firstly, registering an account number on an OceanConnect platform, and informing a client by the platform in an email form to confirm the information of the client when the user opens an account; a user logs in an SPProtal platform to register and log in, manage equipment and establish application, and the platform can automatically record an application ID and generate a password; then, a user writes and uploads a Profile file, writes a coding and decoding plug-in, and performs quality inspection and signature on the coding and decoding plug-in; contacting and e-mail submitting the coding and decoding plug-in to a telecommunication service manager to register and bind equipment; and finally, the equipment uploads the data, joint debugging of the northbound interface of the platform is carried out, the test module is connected with the platform, and the storage function of the test data is tested. Because the platform does not store data, the northbound application server is opened in 24 hours, and when the NB module needs to upload data, the platform automatically establishes connection between the NB module and the northbound application server to perform further data and signaling exchange.

The NB-IoT transport programming flow diagram is shown in fig. 17. Firstly, initializing the module, sending a login program response packet, and detecting whether the communication with the server is available. And then sending a module configuration parameter packet, and configuring some states (AT instructions, part of AT instructions are lost due to power failure, and the AT instructions need to be reconfigured after restarting) to establish communication connection. And after the communication connection is established, waiting for response of the NB module, sending an end packet, and completing preparation work before connection with the platform. And after the configuration is finished, entering an IDLE state, wherein the equipment which has finished the configuration can directly enter the IDLE state.

After entering IDLE state, NB module waits to connect network, if no action is done for a long time (30min), it returns to initialization state and waits to enter next connection. And if the network connection is successful, sending a login packet to the platform, and registering the IMEI number of the module on the Huawei platform. The platform responds after receiving the response packet, returns the response packet and establishes connection. Then the module starts to communicate with the platform, enters a waiting-sending state, and the equipment sends a heartbeat packet (the state of the other party is notified at regular time between the module and the server and sent at a certain time interval) and a fault packet (the fault is reported at a time) while sending a data packet to the platform. And waiting for the platform to respond, continuing to send if the platform successfully accepts, and returning to the idle state if the platform fails to accept until the NB module finishes the communication with the platform.

And uploading the data to an IoT platform, connecting the platform with a server, storing the data in a MySql database, storing the data and waiting for calling of a client.

Further, the step S5 shows that the design of the client specifically includes:

as shown in fig. 18, after the application is opened, the system is initialized to log on the user; and if the login is successful, the platform and the server are communicated. The data retrieved from the server is received in the form of data packets that need to be further deframed. And storing the actual measurement data obtained after the frame is unframed into a local database, so that the drawing tool of the graph can be conveniently called later. The tool for drawing the graph adopts a TeeChart tool which is used as a strong drawing control, and various 2D and 3D graphs can be drawn through the TeeChart tool, so that the tool is attractive and practical. And (4) drawing points and drawing the data, counting the peak values, expressing the trend by using a histogram, and finally realizing the visualization of the data. The obtained data is stored in the local server, so that the calling is convenient.

As shown in fig. 19, initialization is performed first, and the execution order of some files and the assignment of some rights are marked by a Manifest file. And then entering a login page, setting an Android program inlet by using a ManiActivity function, and entering software.

JDBC (Java Database connectivity) provides a standard JavaAPI for executing SQL statements independent of platform, which can conveniently realize the unified operation of various relational databases. When the JDBC is used for connecting the Mysql database, the DbUtils is used as a subclass library for simplifying the operation of the JDBC, and a lot of convenience is provided for development. Next, buttons are defined and button functions are assigned. And pulling the measured data, and drawing a curve through LineChart in an MPAndriod Chart tool.

The specific flow of curve drawing is as follows:

1. adding a dependent GitHub address of the MPChartView and opening the dependent GitHub address to be dependent on the android studio;

2. setting chartview, setting legends, description, displaying characters and the like;

3. setting a Y axis and an X axis;

4. setting data, acquiring a coordinate data set, and creating a package class of the data; setting the color of the fold line, the filling color and the like.

In order to test the performance of the electrochemical sensor-based non-embedded blood glucose monitoring system of the present invention, the following examples were conducted.

The first embodiment is as follows:

solutions with glucose concentrations of 0. mu. mol/L, 5. mu. mol/L, 15. mu. mol/L, 28. mu. mol/L, 35. mu. mol/L, 45. mu. mol/L, and 55. mu. mol/L were prepared using KOH and glucose, respectively. And then testing the prepared solution by using the assembled non-embedded blood glucose detection system, and obtaining the corresponding relation between the glucose concentration and the peak current through the oxidation-reduction reaction carried out under different glucose concentrations. The test results are shown in table 1.

TABLE 1 data sheet of peak current values measured at different glucose concentrations

The correlation between the glucose concentration and the peak current is obtained through tests, and a fitted relation graph is shown in fig. 20, and the linear correlation equation of the glucose concentration and the current response is 0.278 x + 1.83. Glucose concentration has a good correlation with the measured peak current (R)₂0.8475) indicating that the system can react to changes in minute glucose concentrations by changes in peak current, which can be used to detect glucose concentrations on the order of a minute.

Example two:

the correlation between the saliva glucose concentration and the blood glucose concentration is verified by taking normal fasting saliva and blood as samples. The blood glucose concentration was measured by a large-scale biochemical analyzer in a regular hospital, and the measurement of the saliva glucose concentration was measured by the blood glucose detecting system of the present invention. Salivary glucose concentration measurements were made at the same time period after hospital blood glucose measurements.

Rinsing mouth with clear water for 3 times, adding clean and dry absorbent cotton ball into mouth, taking out cotton ball after saliva is naturally secreted, and placing into clean beaker. Then removing the cotton ball, standing to take 10ml of upper saliva sample, diluting to 20ml with KOH solution, and performing repeated measurement for 30 times by using a non-embedded blood glucose detection system to obtain a statistical result of peak current response. The data extraction was finally analyzed as shown in fig. 21. The results of 30 measurements were counted and are shown in Table 2. Mean deviation utilityFormula (II)

The calculation result is 3.7%, and the electrode is proved to have good repeatability.

TABLE 2 data statistics Table for 30 tests of saliva using the non-embedded blood glucose test system of the present invention

The mean value of the peak currents of the measured saliva was 6.7mA, and the glucose concentration in the saliva was calculated to be 36.08. mu. mol/L. The fasting blood glucose concentration of the day measured by the biochemical analyzer of the hospital is 4.6mmol/L, and the result of comparing the glucose concentration in saliva with that in blood is 78%, the result is in line with the expectation.

Example three:

to further verify that the blood glucose test system of the present invention has high accuracy for testing glucose in saliva of different persons, we collected blood and saliva of five normal persons in fasting state. The blood glucose concentration was measured by a large-scale biochemical analyzer in a regular hospital, and the measurement of the saliva glucose concentration was measured by the blood glucose detecting system of the present invention.

First, 10ml of saliva was diluted to 20ml with KOH solution for 5 individuals, respectively. Then, the measurement is performed by using a non-embedded blood glucose detection system, the measurement result is shown in table 4, and the comparison between the test result and the blood glucose value result measured by the hospital is shown in table 5. The final results of the peak current responses at different saliva are shown in FIG. 22.

TABLE 4 data statistics Table for 5-person saliva detection using the non-embedded blood glucose detection system of the present invention

Different persons	1	2	3	4	5
						Current value (mA)	6.95mA	6.9mA	6.98mA	6.97mA	6.96mA

TABLE 5 comparison of data obtained by testing saliva of 5 persons with the non-embedded blood sugar test system of the present invention and blood sugar values measured in hospitals

As can be seen from tables 4 and 5, the measured saliva peak currents of 5 persons were calculated to have glucose concentrations in saliva of 3.742mmol/L, 3.712mmol/L, 3.755mmol/L, 3.798mmol/L and 3.744mmol/L, respectively. The fasting blood glucose concentration of the day measured by a biochemical analyzer of a hospital is respectively 4.7mmol/L, 4.6mmol/L, 4.8mmol/L and 4.7mmol/L, and compared with the glucose concentration of saliva is 79%, 80%, 78% and 79% of the blood, the result is in accordance with the expectation.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. Non-embedded blood sugar detecting system, its characterized in that: the system comprises a microcontroller module, a power supply voltage stabilizing module, a digital-to-analog conversion module, a glucose sensor module, a data transmission module, a background server module, a data calibration module, a data analysis module, a liquid crystal display and PC (personal computer) end and mobile end display modules;

the microcontroller module comprises a microcontroller and a minimum system circuit, wherein the minimum system circuit comprises a download filter circuit and a reset circuit; the download filter circuit adopts capacitor filtering to obtain a voltage signal with a stable waveform; the download filter circuit and the reset circuit realize the burning of the program of the microcontroller and the reset restart of the whole system; the microcontroller completes normal operation and control work of the whole system;

the glucose sensor module converts the change of the glucose concentration in the solution into voltage change and feeds the voltage change back to the microcontroller module for processing and analysis;

the data transmission module realizes wireless data transmission;

the data calibration module calibrates data;

the microcontroller module controls the digital-to-analog conversion module to output triangular wave voltage to act on the glucose sensor module; the glucose sensor module feeds the measured voltage value back to the microcontroller module, the microcontroller module displays the measured voltage value on the liquid crystal display screen, and the data transmission module is used for transmitting the data to the background server module through a wireless transmission technology; the data calibration module performs software calibration on the tested data; the data analysis module calls data of the last seven tests in the memory for data trend analysis; and finally, displaying the data result after processing and analysis on a PC (personal computer) end and a mobile end display module.

2. The non-embedded blood glucose detection system of claim 1, wherein: the glucose sensor module comprises a three-electrode measuring system, wherein the three electrodes are respectively a reference electrode, a counter electrode and a working electrode.

3. The non-embedded blood glucose detection system of claim 2, wherein: the working electrode is a Pd-G-ZnO/NiF electrode.

4. The method of constructing a non-embedded blood glucose test system of any one of claims 1-3, comprising the steps of:

s1: preparing a glucose sensor;

s2: testing the performance of the glucose sensor;

s3: detecting system hardware design;

s4: realizing a wireless transmission function;

s5: and displaying the design of the client.

5. The method for building a non-embedded blood glucose detecting system of claim 4, wherein the specific operations of step S1 include:

s11: cutting the NiF plate into NiF sheets, cleaning and drying;

6. The method of claim 4, wherein the performance test of the glucose sensor in step S2 includes a characterization test and an electrochemical test; the characterization test comprises scanning electron microscope characterization, X-ray diffraction characterization, X-ray photoelectron characterization and determination of electrode surface area; the electrochemical test includes tests for sensitivity, selectivity, and stability of the glucose sensor.

7. The method for constructing a non-embedded blood glucose detecting system of claim 4, wherein step S3 is implemented by using embedded technology to design the hardware of the detecting system.

8. The method for testing a non-embedded blood glucose test system of any one of claims 1-3 and 5-7, comprising the steps of:

s3: diluting with KOH solution in saliva sample;