Wireless charging circuit, glucose sensor preparation method and related device and equipment

Abstract

The invention discloses a wireless charging circuit, a glucose sensor preparation method and a related device and equipment, and relates to the technical field of sensors. The wireless charging circuit provided by the invention comprises a receiving antenna, a matching network, a rectifying circuit, a low-pass filter and an energy storage element which are electrically connected in sequence, radio frequency energy in an environment can be converted into direct current electric energy with high power and high efficiency through a specific circuit structure and circuit parameter design, and the wireless charging circuit is combined with a traditional electric storage for hybrid power supply; long-time and seamless power supply for the electronic equipment can be realized; the invention also provides a preparation method of the glucose sensor, and high sensitivity, high specificity and in-situ analysis detection of the glucose sensor are realized by constructing the molecularly imprinted polymer capable of specifically recognizing glucose, introducing the MXene-AuNPs modified layer and the AuNPs doped molecularly imprinted polymer and embedding a redox probe Prussian blue; the invention also provides a wearable sweat glucose sensor device.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a wireless charging circuit, a method for preparing a glucose sensor, and related devices and equipment. Background Art

[0002] With the development of society, the number of patients with sugar metabolism related diseases such as diabetes is large and is showing a high growth and younger trend; the treatment of sugar metabolism related diseases requires long-term medication, regular examinations and treatment of complications, which brings a heavy economic burden to patients' families and society; at the same time, a large amount of medical resources are used for the diagnosis and treatment of sugar metabolism related diseases, which also puts pressure on the medical system.

[0003] For diabetic patients, continuous monitoring of blood sugar levels is the key to disease management. In current research, wearable sweat glucose sensors can provide a non-invasive, continuous blood sugar monitoring method, reducing the pain and inconvenience of frequent blood sampling for patients, and making it easier for patients to understand their blood sugar changes in real time, so that they can adjust their diet, exercise and drug treatment plans in time, better control their condition and reduce the risk of complications. However, traditional wearable sweat glucose sensors mainly rely on electrical storage devices for power supply. Over time, the power of the electrical storage device will be exhausted and need to be recharged, making it impossible to achieve continuous and dynamic monitoring of sweat glucose. In addition, most wearable sweat glucose sensors are based on glucose oxidase for detection, but the biological enzyme has strict storage conditions, is unstable, is easily affected by the external environment, and the activity of the enzyme will decrease with the number of uses. There are major problems with its sensitivity, repeatability and stability. Summary of the invention

[0004] The embodiments of the present application provide a wireless charging circuit, a method for preparing a glucose sensor, and related devices and equipment, aiming to solve the above-mentioned problems.

[0005] The wireless charging circuit provided in the embodiment of the present application includes: a receiving antenna, a matching network, a rectifier circuit, a low-pass filter and an energy storage element electrically connected in sequence;

[0006] The receiving antenna is used to receive radio frequency energy in the environment, and the radio frequency energy is converted into direct current energy after being processed by the matching network, the rectifier circuit, and the low-pass filter and stored in the energy storage element;

[0007] The matching network includes a first capacitor, a first microstrip line and a second microstrip line;

[0008] The first end of the first capacitor is electrically connected to the receiving antenna, and the second end is electrically connected to the first end of the first microstrip line; the second end of the first microstrip line is electrically connected to the rectifier circuit; the second microstrip line is connected in parallel to the first capacitor; the matching network is used to transmit the radio frequency energy received by the receiving antenna to the rectifier circuit at maximum power;

[0009] The rectifier circuit includes a second capacitor, a third capacitor, a first diode and a second diode;

[0010] The first end of the second capacitor is electrically connected to the second end of the first microstrip line, and the second end is electrically connected to the anode of the second diode; the cathode of the second diode is electrically connected to the low-pass filter;

[0011] The first end of the third capacitor is electrically connected to the cathode of the second diode, and the second end is grounded; the cathode of the first diode is electrically connected to the second end of the second capacitor, and the anode is electrically connected to the second end of the third capacitor.

[0012] Optionally, the low-pass filter includes a third diode, a fourth diode, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line and a seventh microstrip line;

[0013] The anode of the fourth diode is electrically connected to the cathode of the second diode, and the cathode is electrically connected to the first end of the seventh microstrip line; the second end of the seventh microstrip line is electrically connected to the energy storage element;

[0014] The cathode of the third diode is electrically connected to the anode of the fourth diode, and the anode is grounded;

[0015] The third microstrip line, the fourth microstrip line, the fifth microstrip line and the sixth microstrip line are open stubs; wherein the first end of the third microstrip line and the first end of the fourth microstrip line are connected in parallel to the first end of the seventh microstrip line, and the second end of the third microstrip line and the second end of the fourth microstrip line are open; the first end of the fifth microstrip line and the first end of the sixth microstrip line are connected in parallel to the second end of the seventh microstrip line, and the second end of the fifth microstrip line and the second end of the sixth microstrip line are open.

[0016] Optionally, the operating frequency of the receiving antenna is 2.45 GHz;

[0017] The capacitance value of the first capacitor is 1.6-1.8 pF, the length of the first microstrip line is 10-13 mm, and the length of the second microstrip line is 27-30 mm.

[0018] Optionally, the forward operating voltage of the first diode and the second diode when the current passing through is 1 mA is 0.32-0.36V, and the peak reverse voltage is 15V; the capacitance value of the second capacitor and the third capacitor is 50-100 μF.

[0019] Optionally, the length of the third microstrip line is 17-19 mm, the length of the fourth microstrip line is 8.5-9.5 mm, the length of the fifth microstrip line is 4-5 mm, the length of the sixth microstrip line is 4-5 mm, and the length of the seventh microstrip line is 17-19 mm.

[0020] Optionally, the receiving antenna is a half-wave dipole antenna;

[0021] The half-wave dipole antenna is composed of two cylindrical copper rods with a length of 54-58 mm and a radius of 1-1.5 mm, and a feeding gap of 1-1.2 mm.

[0022] Optionally, the receiving antenna further comprises a flexible antenna substrate; the half-wave dipole antenna is arranged on the flexible antenna substrate, and forms a flexible patch antenna with the flexible antenna substrate;

[0023] The flexible patch antenna has a width of 37.5 mm, a length of 28.8 mm, and a distance from the edge of the patch to the feeding point of 5 mm.

[0024] A hybrid power supply device provided in an embodiment of the present application includes a control circuit board, an electrical storage device, and the wireless charging circuit described above;

[0025] The control circuit board is electrically connected to the energy storage element in the wireless charging circuit, and is used to connect the wireless charging circuit to power an external device;

[0026] The control circuit board is also electrically connected to the electrical storage device, and is used to connect the electrical storage device to supply power to the external device;

[0027] The control circuit board is also used to monitor the voltage changes of the wireless charging circuit and the electrical storage device.

[0028] Optionally, when the output voltage of the electrical storage device is less than a preset voltage threshold, the control circuit board switches to the wireless charging circuit to power the external device;

[0029] Alternatively, when the output voltage of the wireless charging circuit is less than a preset voltage threshold, the control circuit board switches to the electrical storage device to supply power to the external device.

[0030] Optionally, the control circuit board is integrated with a data transmission module;

[0031] The data transmission module is used to receive a working signal transmitted by an external device and send the working signal to a remote device.

[0032] An electronic device provided in an embodiment of the present application includes a working device and the hybrid power supply device described above; the hybrid power supply device is used to supply power to the working device;

[0033] The working device is at least one of a sensor, a microcontroller, and an implantable medical device.

[0034] The present invention provides a method for preparing a glucose sensor, the method comprising the following steps:

[0035] S1, preparation of MXene-AuNPs modified electrode: dripping MXene-AuNPs aqueous solution on the surface of printed carbon electrode, drying in a vacuum oven, and then dripping perfluorosulfonic acid membrane solution on the electrode surface;

[0036] S2, preparation of molecular imprinting polymerization precursor solution: preparing a phosphate buffer solution containing glucose, 3-hydroxyphenylboronic acid, catechol, chloroauric acid trihydrate, ferric chloride, potassium ferrocyanide, potassium chloride, and hydrochloric acid;

[0037] S3, preparing AuNPs-doped molecularly imprinted polymer by electropolymerization: immersing the MXene-AuNPs modified electrode obtained in step S1 into the molecularly imprinted polymer precursor solution prepared in step S2, and performing electropolymerization by cyclic voltammetry;

[0038] S4, eluting the template molecule: using cyclic voltammetry to elute the template molecule glucose in the molecularly imprinted polymer prepared in step S3 to obtain a working electrode for the glucose sensor.

[0039] Optionally, the preparation method of the MXene-AuNPs aqueous solution is as follows:

[0040] Mix 5-10 mg / mL MXene and 0.02-0.06 mg / mL AuNPs at a volume ratio of 1:1-1:30, and stir at room temperature for 10-15 hours to obtain a mixed solution of MXene and AuNPs;

[0041] The mixed solution of MXene and AuNPs was centrifuged at 15000 rpm for 15-30 minutes, the supernatant was removed, and the product was washed twice with ultrapure water, the centrifugation step was repeated, and the product was dried in a vacuum oven at 60 °C to finally obtain powdered MXene-AuNPs;

[0042] Powdered MXene-AuNPs were dispersed in ultrapure water to prepare a 0.5-2 mg / mL MXene-AuNPs aqueous solution.

[0043] Optionally, in step S1, the amount of the MXene-AuNPs aqueous solution added is 2-8 mL; the drying temperature of the vacuum oven is 60° C.; the concentration of the perfluorosulfonic acid membrane solution is 0.05 wt %, and the amount of the solution added is 2-5 mL.

[0044] Optionally, in step S2, the molecular imprinting polymerization precursor solution is a phosphate buffer solution with a pH of 7.4 containing 1-8 mM glucose, 5-20 mM 3-hydroxyphenylboronic acid, 10-30 mM catechol, 0.1-0.6 mM chloroauric acid trihydrate, 3-20 mM ferric chloride, 3-20 mM potassium ferrocyanide, 0.1-0.3 M potassium chloride, 0.1-0.3 M hydrochloric acid, and 0.01-0.3 M phosphate.

[0045] Optionally, in step S3, the voltage range of electropolymerization is -0.9-1.0 V, the scanning speed is 25-100 mV / s, and the number of scanning circles is 5-20 circles.

[0046] Optionally, in step S4, the elution conditions for eluting the template molecules are: a voltage range of -0.9-1.0 V, a scanning speed of 25-100 mV / s, and a scanning number of 5-20 circles.

[0047] A glucose sensor provided in an embodiment of the present application includes a sensor substrate, and a reference electrode, a counter electrode and a glucose sensor working electrode prepared by the above preparation method, which are arranged on the sensor substrate.

[0048] A wearable sweat glucose sensor device provided in an embodiment of the present application includes a flexible substrate, the hybrid power supply device described above, and the glucose sensor described above;

[0049] The control circuit board of the hybrid power supply device is electrically connected to the glucose sensor, and the hybrid power supply device is used to supply power to the glucose sensor; the hybrid power supply device and the glucose sensor are both arranged on the flexible substrate.

[0050] It can be seen from the above technical solutions that the present invention has the following beneficial effects:

[0051] 1. The wireless charging circuit provided by the present invention can convert the radio frequency energy in the environment into DC power with maximum power and efficiency and store it in the energy storage element, thereby providing a wireless charging solution for various electronic devices. It can be combined with the traditional electrical storage device for hybrid power supply to achieve long-term and seamless power supply for electronic devices.

[0052] 2. The preparation method of the glucose sensor provided by the present invention utilizes MXene-AuNPs to modify the printed carbon electrode, which can greatly enhance the conductivity of the electrode through the synergistic effect, and provide a good channel for the electron transfer between the molecular imprinting cavity and the carbon electrode; at the same time, doping AuNPs in the molecular imprinting polymer can further improve the conductivity of the molecular imprinting polymer; in addition, the present invention embeds the redox probe Prussian blue into the molecular imprinting polymer through a co-electropolymerization method, which can not only improve the electron transfer efficiency together with the doped gold nanoparticles, but also realize the in-situ direct monitoring of glucose without the need for additional redox probes; finally, 3-hydroxyphenylboronic acid and catechol are used as functional monomers, which can form a three-dimensional complementary structure with glucose through multiple interactions such as hydrogen bonds, thereby increasing the specific recognition ability of the molecular imprinting cavity for glucose; therefore, the glucose sensor prepared by this method has the characteristics of high sensitivity, high specificity and in-situ analysis;

[0053] 3. The wearable sweat glucose sensor device provided by the present invention combines all the features of the wireless charging circuit technical solution and the glucose sensor preparation method technical solution, and has the beneficial effects of long-term, seamless power supply as well as high sensitivity, high specificity and in-situ analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0055] Figure 1 This is a circuit structure diagram of an embodiment of a wireless charging circuit of the present invention;

[0056] Figure 2 A circuit diagram of an embodiment of a matching network of the present invention;

[0057] Figure 3 A circuit structure diagram of an embodiment of a rectifier circuit of the present invention;

[0058] Figure 4 A circuit diagram of an embodiment of a low-pass filter of the present invention;

[0059] Figure 5 The reflection response (S11) curve of the matching network at the input end at different frequencies simulated by the LSSP simulator of the present invention;

[0060] Figure 6It is the S11-L2 simulation curve of the matching network of the present invention (L1=10.892mm);

[0061] Figure 7 It is the S11-L2 simulation curve of the matching network of the present invention (L1=9.5mm);

[0062] Figure 8 It is the S11-L2 simulation curve of the matching network of the present invention (L1=11.75mm);

[0063] Fig. 9 is the reflection response (S11) curve of the matching network of the present invention under different L1 and L2 values;

[0064] Fig.10 is a schematic diagram of the structure of the glucose sensor of the present invention;

[0065] Fig.11 is a flowchart of a method for preparing a glucose sensor of the present invention;

[0066] Fig.12 is a structural block diagram of a wearable sweat glucose sensor device of the present invention;

[0067] Fig.13 for Fig.12 Schematic diagram of the assembly of the wearable sweat glucose sensor device shown.

[0068] Description of Figure Numbers:

[0069] 100. Wireless charging circuit; 101. Receiving antenna; 102. Matching network; 103. Rectification circuit; 104. Low-pass filter; 105. Energy storage element; 200. Control circuit board; 300. Electrical storage device; 400. Glucose sensor; 401. Reference electrode; 402. Working electrode; 403. Counter electrode; 404. Sensor substrate; 500. Flexible substrate. DETAILED DESCRIPTION

[0070] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] Explanation of professional terms:

[0072] MXene: Transition metal carbon / nitride two-dimensional nanolayered materials, such as Ti3C2T X 、Ti2CTX 、V2CT X wait;

[0073] AuNPs: gold nanoparticles.

[0074] At present, wearable sweat glucose sensors mainly rely on electrical storage devices for power supply, but when the electrical storage device runs out of power, it needs to be recharged. When the user is out for a long time or replaces the electrical storage device, the traditional wearable sweat glucose sensor powered by the electrical storage device has a single power supply form and cannot achieve long-term, continuous and real-time monitoring. Therefore, how to perform wireless charging and power supply is an urgent problem that needs to be solved to achieve long-term, continuous and dynamic monitoring of wearable sweat glucose sensors.

[0075] There are three main transmission methods for wireless charging: electromagnetic induction, radio frequency, and magnetic field resonance. Among them, electromagnetic induction charging uses an electromagnetic field to transfer energy between two coils (a transmitter and a receiver). This technology is relatively mature (such as wireless charging based on the Q1 standard) and is usually used on charging pads for devices such as smartphones and electric toothbrushes; magnetic field resonance charges through resonant inductive coupling formed by tuning the transmitter and receiver to the same frequency. Magnetic field resonance allows energy transmission at a greater distance and greater spatial freedom.

[0076] After extensive research and investigation, the applicant found that both electromagnetic induction and magnetic field resonance require precise alignment of the transmitter and receiver. A slight deviation in position will affect the charging effect, and the effective transmission distance is usually short. Beyond the range, the efficiency drops significantly. With the popularization of 5G mobile communications and the development of 6G networks in the future, it will become easier and more convenient to obtain electromagnetic wave energy. RF wireless has the advantages of long energy transmission distance, controllable energy transmission direction, and precise positioning. Therefore, RF wireless charging is expected to achieve long-term and seamless power supply for wearable sweat glucose sensors.

[0077] In addition, the applicant also found in the research and investigation that traditional glucose sensors are based on glucose oxidase for detection, but the biological enzyme has strict storage conditions, is unstable, and is easily affected by the external environment, and the activity of the enzyme will decrease with the number of uses; there are also enzyme-free sweat glucose sensors based on nanozymes in current research, such as gold nanoparticles, gold-silver composite nanomaterials, etc., but the specificity and sensitivity of the currently constructed nanozyme glucose sensors are low, which greatly limits its application in the field of wearable sweat sensors; some other studies use molecular imprinting polymer technology to simulate the characteristics of specific interactions between enzymes and substrates, thereby achieving specific and specific identification and detection of targets, but the current glucose sensors based on molecular imprinting polymers have problems such as low sensitivity and the need for additional redox probes; therefore, existing glucose sensors still have major problems in sensitivity, specificity and stability.

[0078] The present invention proposes a wireless charging circuit, which aims to utilize radio frequency energy in the environment to provide a wireless charging solution for electronic devices such as wearable sweat glucose sensors.

[0079] See also Figure 1 In one embodiment, the wireless charging circuit includes: a receiving antenna 101, a matching network 102, a rectifier circuit 103, a low-pass filter 104 and an energy storage element 105 which are electrically connected in sequence;

[0080] The receiving antenna 101 is used to receive radio frequency energy in the environment. The radio frequency energy is processed by the matching network 102 , the rectifier circuit 103 , and the low-pass filter 104 in sequence, and then converted into direct current energy and stored in the energy storage element 105 .

[0081] Among them, radio frequency energy refers to the electromagnetic wave energy of radio frequency wireless signals. Radio frequency wireless signals include electromagnetic waves in frequency bands such as mobile communications (such as 4G, 5G and future 6G), wireless local area networks (such as WiFi, Bluetooth, etc.), wireless broadcasting, and satellite communications.

[0082] In this embodiment, the matching network 102 is used to achieve impedance matching between the source end and the rectifier circuit 103, thereby minimizing signal reflection and improving power transmission efficiency; the rectifier circuit 103 is used to convert the RF signal into a DC signal, that is, to convert the RF energy into DC energy; the low-pass filter 104 is used to control the high-order harmonics generated during the rectification process and improve the power conversion efficiency from RF to DC.

[0083] In this embodiment, the energy storage element 105 can be an energy storage capacitor; in other embodiments, rechargeable batteries, supercapacitors and other energy storage elements with higher energy density can also be selected to meet the demand for longer battery life. Nanostructured energy storage materials or conductive polymer / organic free radical batteries and other new energy storage elements can also be selected to meet the demand for flexibility, electrochemical properties or various unique physical and chemical properties.

[0084] In this embodiment, the specific circuit structure of the wireless charging circuit is as follows:

[0085] The matching network 102 includes a first capacitor C1, a first microstrip line TL1 and a second microstrip line TL2;

[0086] The first end of the first capacitor C1 is electrically connected to the receiving antenna 101, and the second end of the first capacitor C1 is electrically connected to the first end of the first microstrip line TL1; the second end of the first microstrip line TL1 is electrically connected to the rectifier circuit 103; the second microstrip line TL2 is connected in parallel with the first capacitor C1; the matching network 102 is used to transmit the RF energy received by the receiving antenna to the rectifier circuit with maximum power.

[0087] The matching network 102 is a lumped element impedance matching structure and adopts a single shorting rod matching circuit design, the purpose of which is to change the input impedance of the circuit by adding a shorting rod to ensure maximum power transmission or signal transmission efficiency.

[0088] The rectifier circuit 103 includes a second capacitor C2, a third capacitor C3, a first diode D1 and a second diode D2;

[0089] The first end of the second capacitor C2 is electrically connected to the second end of the first microstrip line TL1, and the second end is electrically connected to the anode of the second diode D2; the cathode of the second diode D2 is electrically connected to the low-pass filter 104;

[0090] The first end of the third capacitor C3 is electrically connected to the cathode of the second diode D2, and the second end of the third capacitor C3 is grounded; the cathode of the first diode D1 is electrically connected to the second end of the second capacitor C2, and the anode of the first diode D1 is electrically connected to the second end of the third capacitor C3.

[0091] Specifically, the rectifier circuit 103 is a double voltage RF rectifier structure. The RF signal is input through the second capacitor C2. After being rectified by the first diode D1 and the second diode D2, the second capacitor C2 and the third capacitor C3 store the voltage of the positive half cycle and the negative half cycle respectively, thereby doubling the voltage.

[0092] The low-pass filter 104 includes a third diode D3, a fourth diode D4, a third microstrip line TL3, a fourth microstrip line TL4, a fifth microstrip line TL5, a sixth microstrip line TL6 and a seventh microstrip line TL7;

[0093] The anode of the fourth diode D4 is electrically connected to the cathode of the second diode D2, and the cathode of the fourth diode D4 is electrically connected to the first end of the seventh microstrip line TL7; the second end of the seventh microstrip line TL7 is electrically connected to the energy storage element 105; the cathode of the third diode D3 is electrically connected to the anode of the fourth diode D4, and the anode of the third diode D3 is grounded;

[0094] The first end of the third microstrip line TL3 and the first end of the fourth microstrip line TL4 are connected in parallel to the first end of the seventh microstrip line TL7, and the second end of the third microstrip line TL3 and the second end of the fourth microstrip line TL4 are open; the first end of the fifth microstrip line TL5 and the first end of the sixth microstrip line TL6 are connected in parallel to the second end of the seventh microstrip line TL7, and the second end of the fifth microstrip line TL5 and the second end of the sixth microstrip line TL6 are open.

[0095] Specifically, the third microstrip line TL3, the fourth microstrip line TL4, the fifth microstrip line TL5 and the sixth microstrip line TL6 of the low-pass filter 104 are parallel open-circuit stubs for terminating radio frequency harmonics; the seventh microstrip line TL7 is a main circuit series microstrip line for providing a path for DC signals; the third diode D3 and the fourth diode D4 are used to further rectify the reflected harmonic energy to improve the rectification efficiency.

[0096] The energy storage element 105 may use an energy storage capacitor C5, and the capacitance value of the energy storage capacitor C5 ranges from 0.2 to 0.8 F to meet the wireless charging requirements of small flexible electronic devices such as wearable sweat glucose sensors.

[0097] The wireless charging circuit proposed in the embodiment of the present invention receives radio frequency energy from the environment through the receiving antenna 101, and transmits the maximum power received by the receiving antenna to the rectifier circuit 103 through the matching network 102; the rectifier circuit 103 is responsible for collecting radio frequency energy and converting it into direct current energy and storing it in the energy storage element 105. During the rectification process, some unnecessary high-order harmonics generated can be controlled by the low-pass filter 104; therefore, the wireless charging circuit proposed in the present invention can collect radio frequency energy in the environment with high power and high efficiency to charge electronic devices, which not only provides a solution for wireless charging of electronic devices, but can also be further combined with traditional electrical storage devices for power supply to solve the current problems of single power supply, instability, and inability to be used for a long time in small flexible electronic devices.

[0098] Based on the specific circuit structure of the wireless charging circuit provided in the above embodiment, taking the 2.45 GHz Bluetooth signal frequency band as an example, the circuit parameters of the wireless charging circuit are designed in detail through the following specific embodiments.

[0099] In these embodiments, the operating frequency of the receiving antenna is 2.45 GHz, the maximum operating bandwidth is 500 MHz, and the wavelength λ0 corresponding to the 2.45 GHz frequency band is 74.3487 mm; the 2.45 GHz frequency band has good propagation characteristics and moderate energy density, and is suitable for short-distance and medium-distance wireless charging.

[0100] See also Figure 2 In a specific embodiment, the input power of the matching network is specified to be 30 dBm, and the parameters to be designed for the matching network include: the capacitance value of the first capacitor C1, the length L1 of the first microstrip line TL1, and the length L2 of the second microstrip line TL2. Figure 5 The reflection response (S11) curve of the matching network at the input end at different frequencies simulated using the LSSP (Large Signal S-Parameter) simulator is shown in Figure 1. Figure 5 It can be clearly observed that the operating frequency of the matching network is not 2.45GHz calculated by the Smith Chart tool. This is because the rectifier circuit is nonlinear and its input impedance changes with the input signal. Therefore, when designing a matching circuit, the nonlinear characteristics of the diode must be taken into account, not just the impedance matching at a specific frequency.

[0101] Specifically, the matching network is designed as a single short-circuit rod matching circuit, which can be designed using the following simplified method: a. Since the input capacitance value has little effect on the overall efficiency, the capacitance value of the first capacitor C1 can be selected appropriately to reduce one degree of freedom; b. For the other two degree-of-freedom parameters (L1 and L2), by adjusting L1 and performing S11-L2 simulation at the same time, a set of L1 and L2 values ​​can be found to obtain the best S11 performance, where S11 represents the input end reflection coefficient response.

[0102] The adjustment range of L1 and L2 is 0 to half wavelength, that is, 0 to 37.174 mm. In this design, the L1 value is first fixed to 10.892 mm, and the S11-L2 simulation curve is obtained (see Figure 6 ),from Figure 6 It can be seen that the optimal L2 value is 29.00mm; similarly, for different L1 values, different S11-L2 simulation curves can be obtained, see Figure 7 and Figure 8 , Figure 7 This is the S11-L2 simulation curve when the L1 value is 9.5mm. Figure 8 This is the S11-L2 simulation curve when the L1 value is 11.75mm; combined Figure 6 , Figure 7 and Figure 8 The simulation results show that Fig. 9 , Fig. 9The reflection response (S11) curve of the matching network under different L1 and L2 values.

[0103] Based on the above simulation results, it can be obtained that the capacitance value of the first capacitor C1 of the matching network ranges from 1.6 to 1.8 pF, the length of the first microstrip line TL1 ranges from 10 to 13 mm, and the length of the second microstrip line TL2 ranges from 27 to 30 mm.

[0104] In a preferred embodiment, the capacitance value of the first capacitor C1 is selected to be 1.7 pF, the length of the first microstrip line TL1 is selected to be 11 mm, and the length of the second microstrip line TL2 is selected to be 29 mm.

[0105] See also Figure 3 In a specific embodiment, the forward operating voltage of the first diode D1 and the second diode D2 in the rectifier circuit is 0.32-0.36V when the current passing through is 1mA, and the peak reverse voltage is 15V; the capacitance value of the second capacitor C2 and the third capacitor C3 ranges from 50-100μF.

[0106] In a preferred embodiment, both the first diode D1 and the second diode D2 can be HSMS-2820 diodes.

[0107] In a preferred embodiment, the capacitance values ​​of the second capacitor C2 and the third capacitor C3 are selected to be 60 μF.

[0108] See also Figure 4 In one embodiment, the input impedance Z of the open circuit stub of the low-pass filter is oc In the lossless case, it can be given by formula (1):

[0109] (1)

[0110] in is the wavelength, is the physical length of the open stub; for the 2.45 GHz band, λ=74.3487 mm, the propagation constant .

[0111] When the physical length of the open stub When the input impedance of the open stub is Z oc Satisfies formula (2):

[0112] (2)

[0113] From equation (2), we can see that for the signal corresponding to the operating frequency of 2.45 GHz, the open stub with a length of one quarter wavelength behaves as a short circuit. In addition, for odd harmonic frequencies ( , n is an odd number), the input impedance of an open stub with a length of 18.567 mm is also equivalent to a short circuit, that is:

[0114] , n is an even number; (3)

[0115] The above-mentioned quarter-wavelength 18.567mm open-circuit stub can not only short-circuit the second harmonic signal at the second harmonic frequency, but also short-circuit its odd-order harmonics, that is:

[0116] , n is an even number; (4)

[0117] Therefore, the low-pass filter can cut off up to the 7th harmonic and allow the DC signal to pass. According to the above derivation, the theoretical length of the open-circuit stub in the low-pass filter can be obtained:

[0118] exist The length of the quarter-wavelength open-circuit stub at is:

[0119]

[0120] exist The length of the quarter-wavelength open-circuit stub at is:

[0121]

[0122] exist The length of the quarter-wavelength open-circuit stub at is:

[0123]

[0124] Similarly, for the DC path, The length of the half-wavelength open circuit stub is:

[0125]

[0126] See also Figure 4 , the four parallel open short stubs in the low-pass filter are the third microstrip line TL3, the fourth microstrip line TL4, the fifth microstrip line TL5 and the sixth microstrip line TL6, and the series microstrip line is the seventh microstrip line TL7; based on the above theoretical reference values, it can be obtained that the length range of the third microstrip line TL3 is 17-19mm, the length range of the fourth microstrip line TL4 is 8.5-9.5mm, the length range of the fifth microstrip line TL5 and the sixth microstrip line TL6 are both 4-5mm, and the length range of the seventh microstrip line TL7 is 17-19mm; the cutoff frequencies corresponding to the above open short stubs TL3, TL4, TL5 and TL6 are respectively .

[0127] In a preferred embodiment, the length of the third microstrip line TL3 is 18.6 mm, the length of the fourth microstrip line TL4 is 9.3 mm, the lengths of the fifth microstrip line TL5 and the sixth microstrip line TL6 are both 4.7 mm, and the length of the seventh microstrip line TL7 is 18.6 mm.

[0128] In a preferred embodiment, the forward operating voltage of the third diode D3 and the fourth diode D4 is 0.32-0.36V and the peak reverse voltage is 15V when the current passing through the diode is 1mA.

[0129] In a preferred implementation manner, both the third diode D3 and the fourth diode D4 can be HSMS-2820 diodes.

[0130] In a specific embodiment, Figure 4 The load in the circuit is a storage capacitor, and the capacitance value of the storage capacitor is selected to be 0.5F.

[0131] In a specific embodiment, the receiving antenna is a half-wave dipole antenna, which is composed of two cylindrical copper rods with a length of 54-58 mm and a radius of 1-1.5 mm. The feed gap is represented by g, g=1-1.2 mm.

[0132] In another specific embodiment, the wireless charging circuit provided by the embodiment of the present invention is used for a flexible wearable electronic device, and a flexible antenna is selected as the receiving antenna.

[0133] In a preferred embodiment, the flexible antenna is a rectangular microstrip patch antenna, whose substrate material is made of polyimide (Kapton) and polyethylene terephthalate (PET), the patch width is 36-38 mm, the length is 27-29 mm, the distance from the edge of the patch to the feeding point is 4.5-5.5 mm, and the thickness of the substrate material is 0.08-0.15 mm; the flexible antenna can adapt to various non-planar surfaces, is easy to bend, stretch or compress, and is more durable than traditional rigid antennas.

[0134] In a preferred embodiment, the width of the rectangular microstrip patch antenna is selected to be 37.5 mm, the length is selected to be 28.8 mm, the distance from the edge of the patch to the feeding point is 5 mm, and the thickness of the substrate material is selected to be 0.1 mm.

[0135] It can be seen from the above embodiments that the present invention proposes a wireless charging circuit composed of a receiving antenna, a matching network, a rectifier circuit, a low-pass filter and an energy storage element which are electrically connected in sequence. Through a specific circuit structure design, it is realized to receive radio frequency energy from the environment and convert the radio frequency energy into direct current energy and store it in the energy storage element, and then wirelessly charge the electronic device. Based on this specific circuit structure, the embodiment of the present invention also designs specific circuit parameters corresponding to the wireless charging circuit when the working frequency band is 2.45GHz, so as to realize high-power and high-efficiency radio frequency wireless charging under the 2.45GHz working frequency band.

[0136] It should be noted that the above embodiments are exemplary designs of circuit parameters in the 2.45GHz frequency band. The wireless charging circuit proposed in the present invention is not only applicable to the 2.45GHz frequency band, but also to various radio frequency bands in any environment, such as WIFI frequency band, millimeter wave frequency band, etc. In practical applications, the circuit parameters can be adjusted accordingly according to different frequency band requirements and specific usage scenarios. For example, for other specific frequency bands, it is necessary to recalculate and optimize the parameters of key parts such as matching networks, rectifier circuits, filters, etc. to ensure that the wireless charging circuit can work efficiently and stably in this frequency band.

[0137] Based on the above embodiments of the wireless charging circuit, the present invention provides a hybrid power supply device.

[0138] In some embodiments, the hybrid power supply device includes the wireless charging circuit provided in the above embodiments, as well as a control circuit board and an electrical storage device;

[0139] The control circuit board is electrically connected to the energy storage element in the wireless charging circuit, and is used to connect the wireless charging circuit to power external devices. It is also electrically connected to the electric storage device, and is used to connect the electric storage device to power external devices. The control circuit board is also used to monitor the voltage changes of the wireless charging circuit and the electric storage device.

[0140] Among them, the external device can be a sensor, a microcontroller, an implantable medical device, etc.

[0141] In one embodiment, when the output voltage of the electric storage device is less than a preset voltage threshold, the control circuit board switches to the wireless charging circuit to power the external device; alternatively, when the output voltage of the wireless charging circuit is less than a preset voltage threshold, the control circuit board switches to the electric storage device to power the external device; wherein the preset voltage threshold needs to be set according to the effective working voltage required by the external device in the actual application scenario, for example, the working voltage of the flexible wearable glucose sensor is around 0.1-1V, and the preset voltage threshold can be selected as a suitable value close to 0.1V.

[0142] In addition, the control circuit board can further combine advanced control technology and algorithms to intelligently manage the wireless charging process. For example, by real-time monitoring of charging status and device requirements, the output power can be dynamically adjusted to achieve the best charging effect; using intelligent recognition technology, different types of external devices can be automatically adapted to improve charging compatibility and convenience.

[0143] In another embodiment, the control circuit board is integrated with a data transmission module;

[0144] The data transmission module is used to receive working signals transmitted by external devices, such as detection signals collected by sensors, and send the working signals to remote devices for viewing and analysis.

[0145] It is understandable that in the embodiments of these hybrid power supply devices, the electrical storage device refers to an independent energy storage element such as a battery (lithium-ion battery, polymer battery, zinc battery, micro fuel cell, etc.), a supercapacitor, etc.

[0146] In one embodiment, the power supply voltage of the electrical storage device is 1-2V to meet the power supply requirements of small electronic devices such as flexible wearable sweat glucose sensor devices.

[0147] Compared with the energy storage elements in the wireless charging circuit, the electric storage device has a larger and more stable capacity, but when the power is exhausted, it needs to be replaced with a new one or connected to an external charger for charging, and it is impossible to achieve long-term and seamless power supply.

[0148] Therefore, the hybrid power supply device provided by the present invention combines a wireless charging circuit and an electric storage device to provide hybrid power supply to external devices. When the power of the electric storage device is exhausted and the use environment is not convenient for replacing the electric storage device or external charging of the electric storage device, the wireless charging circuit can use the radio frequency energy in the environment to power the external device in time, thereby achieving long-term and seamless power supply and avoiding the hidden danger of equipment shutdown caused by the single power supply form of the electric storage device.

[0149] Based on the above embodiments of the hybrid power supply device, the present invention further provides an electronic device.

[0150] In some embodiments, the electronic device includes the hybrid power supply device provided in the above embodiments, and a working device, wherein the hybrid power supply device is used to power the working device; the working device is at least one of a sensor, a microcontroller, and an implantable medical device.

[0151] It can be understood that the hybrid power supply device proposed in the above embodiment can be applied to a variety of different electronic devices.

[0152] For example, in a specific embodiment, the hybrid power supply device is used to power a flexible sensor, which may be a glucose sensor, a lactate sensor, a blood pressure sensor, a heart rate sensor, a temperature sensor, etc. One or more of these sensors are used to construct a flexible wearable device. When the user is engaged in outdoor activities, the hybrid power supply device can power the flexible wearable device for a long time and seamlessly, thereby realizing long-term continuous monitoring of human physiological signals.

[0153] In another specific embodiment, the hybrid power supply device is used to power microcontrollers of various small and micro household electronic devices or outdoor electronic devices (such as smart doorbells, small speakers, micro cameras, sports bracelets, etc.) to process sensor data and control device functions; in some environments where wired charging is difficult, such as special industrial monitoring scenarios or outdoor environments, the hybrid power supply device is used to power the microcontroller to ensure continuous operation of the device.

[0154] In another specific embodiment, the hybrid power supply device can also be used to power implantable medical devices, such as smart patch drug delivery systems, wearable rehabilitation equipment, etc. These devices usually require miniaturized, lightweight and stable power supply solutions. The hybrid power supply device provided in the embodiments of the present invention can meet these requirements.

[0155] The present invention also proposes a method for preparing a glucose sensor based on molecular imprinting technology, aiming to solve the problems existing in the detection sensitivity, specificity and stability of current glucose sensors.

[0156] See also Fig.11 In one embodiment, a method for preparing a glucose sensor comprises the following steps:

[0157] S1, preparation of MXene-AuNPs modified electrode: dripping MXene-AuNPs aqueous solution on the surface of printed carbon electrode, drying in a vacuum oven, and then dripping perfluorosulfonic acid membrane solution on the electrode surface;

[0158] S2, preparation of molecular imprinting polymerization precursor solution: preparing a phosphate buffer solution containing glucose, 3-hydroxyphenylboronic acid, catechol, chloroauric acid trihydrate, ferric chloride, potassium ferrocyanide, potassium chloride, and hydrochloric acid;

[0159] S3, preparing AuNPs-doped molecularly imprinted polymer by electropolymerization: immersing the MXene-AuNPs modified electrode obtained in step S1 into the molecularly imprinted polymer precursor solution prepared in step S2, and performing electropolymerization by cyclic voltammetry;

[0160] S4, eluting the template molecule: using cyclic voltammetry to elute the template molecule glucose in the molecularly imprinted polymer prepared in step S3 to obtain a working electrode for the glucose sensor.

[0161] In this embodiment, step S1 modifies MXene-AuNPs on the printed carbon electrode, greatly enhancing the conductivity of the electrode through a synergistic effect, and providing a good channel for electron transfer between the molecular imprinted cavity and the carbon electrode; the perfluorosulfonic acid film can improve the interface compatibility and conductivity of the electrode, and provide a protective film for the electrode to prevent the electrode from being affected by the external environment.

[0162] In step S3, 3-hydroxyphenylboronic acid and catechol are used as functional monomers. The hydroxyl group, benzene ring, etc. in their structures can form hydrogen bonds with the hydroxyl group, carbonyl group, etc. in glucose molecules. In addition to hydrogen bonding, there may be other interactions between the functional monomers and glucose, such as π-π stacking, electrostatic interaction, etc. 3-hydroxyphenylboronic acid and catechol form a three-dimensional complementary structure with glucose molecules through multiple interactions such as hydrogen bonding under electropolymerization reaction, thereby increasing the specific recognition ability of the molecular imprinting cavity for glucose.

[0163] In step S3, the trivalent gold ions in chloroauric acid trihydrate are reduced to gold nanoparticles (AuNPs). AuNPs are doped in the molecularly imprinted polymer, which can further improve the conductivity of the molecularly imprinted polymer, and can greatly improve the electron transfer efficiency inside the molecularly imprinted polymer, thereby improving the detection sensitivity.

[0164] In step S3, ferric chloride and potassium ferrocyanide react under appropriate conditions to generate Prussian blue (ferric ferrocyanide) precipitate. Prussian blue has a good skeleton structure, can be combined with other materials to form a ternary structure, and has good redox activity. The redox probe Prussian blue is embedded into the molecular imprinted polymer by co-electropolymerization, which can not only improve the electron transfer efficiency together with the doped gold nanoparticles, but also realize the in situ direct monitoring of glucose without the need for additional redox probes.

[0165] In step S4, after the template molecules are eluted, three-dimensional holes matching the shape, size and functional group arrangement of the template molecules are left in the molecularly imprinted polymer; these holes have selective recognition properties for the template molecules and their analogs, and can specifically recognize and bind to glucose molecules.

[0166] In practical applications, when a sample solution containing glucose (such as sweat) comes into contact with a molecularly imprinted polymer, the glucose molecules will specifically bind to the imprinted holes in the polymer and undergo a redox reaction under the action of the redox probe Prussian blue. The glucose sensor of this embodiment uses a three-electrode electrochemical system to detect the glucose concentration. When a reduction reaction occurs on the working electrode, an oxidation reaction occurs on the counter electrode, and vice versa. By measuring the potential difference between the working electrode and the reference electrode, combined with the known reference electrode potential, the reaction on the working electrode can be accurately determined, and then the glucose concentration in the sample solution can be judged.

[0167] Based on the above preparation method examples, in a specific embodiment, the preparation method of MXene-AuNPs aqueous solution is as follows:

[0168] Mix 5-10 mg / mL MXene and 0.02-0.06 mg / mL AuNPs at a volume ratio of 1:1-1:30, and stir at room temperature for 10-15 hours to obtain a mixed solution of MXene and AuNPs;

[0169] The mixed solution of MXene and AuNPs was centrifuged at 15000 rpm for 15-30 minutes, the supernatant was removed, and the product was washed twice with ultrapure water, the centrifugation step was repeated, and the product was dried in a vacuum oven at 60 °C to finally obtain powdered MXene-AuNPs;

[0170] Powdered MXene-AuNPs were dispersed in ultrapure water to prepare a 0.5-2 mg / mL MXene-AuNPs aqueous solution.

[0171] Based on the MXene-AuNPs aqueous solution prepared in this embodiment, in step S1, the amount of the MXene-AuNPs aqueous solution added is 2-8 mL; the drying temperature of the vacuum oven is 60° C.; the concentration of the perfluorosulfonic acid membrane solution is 0.05 wt %, and the amount of the solution added is 2-5 mL.

[0172] In a specific embodiment, the molecular imprinting polymerization precursor solution is a phosphate buffer solution with a pH of 7.4 containing 1-8 mM glucose, 5-20 mM 3-hydroxyphenylboronic acid, 10-30 mM catechol, 0.1-0.6 mM chloroauric acid trihydrate, 3-20 mM ferric chloride, 3-20 mM potassium ferrocyanide, 0.1-0.3 M potassium chloride, 0.1-0.3 M hydrochloric acid, and 0.01-0.3 M phosphate.

[0173] Based on the molecular imprinting polymerization precursor solution prepared in this embodiment, in step S3, the voltage range of electropolymerization is -0.9-1.0V, the scanning speed is 25-100mV / s, and the number of scanning circles is 5-20 circles.

[0174] In step S4, the elution conditions for eluting the template molecules are: voltage range -0.9-1.0 V, scanning speed 25-100 mV / s, and scanning number of 5-20 circles.

[0175] Based on the glucose sensor working electrode prepared in the above preparation method embodiment, the present invention provides a glucose sensor.

[0176] See also Fig.10 In one embodiment, the glucose sensor includes a sensor substrate 404 and a working electrode 402 , a reference electrode 401 , and a counter electrode 403 disposed on the sensor substrate 404 .

[0177] In a preferred embodiment, the sensor substrate 404 is a flexible substrate, and the material selected is polyethylene terephthalate (PET).

[0178] It can be understood that after the embodiment of the aforementioned preparation method prepares the working electrode 402 of the glucose sensor in step S4, it is also necessary to prepare the reference electrode 401 and the counter electrode 403, and assemble the working electrode 402, the reference electrode 401, the counter electrode 403 and the sensor substrate 404 to obtain the target glucose sensor; the reference electrode 401 and the counter electrode 403 can be made of electrodes of different materials such as metal electrodes, graphite electrodes, and printed carbon electrodes.

[0179] It can be seen from the above that the glucose sensor prepared by the aforementioned preparation method embodiment has the beneficial effects of high sensitivity, high specificity, high stability and in situ analysis; compared with traditional bio-enzyme glucose sensors, the glucose sensor has better stability and repeatability; compared with nanoenzyme glucose sensors, the glucose sensor has higher specificity and sensitivity; compared with some glucose sensors based on molecular imprinting polymers, which have low sensitivity and require the additional addition of redox probes, the glucose sensor has higher sensitivity and can achieve in situ analysis.

[0180] It should be noted that the glucose sensor prepared in the above embodiments can be used for the management and diagnosis of glucose metabolism diseases, and can also be used in various application scenarios that require glucose detection, such as food industry, environmental monitoring, biomedical research, etc.

[0181] In combination with the technical solution of the above hybrid power supply device and the glucose sensor prepared by the glucose sensor preparation method, the present invention also proposes a wearable sweat glucose sensor device.

[0182] See also Fig.12 and Fig.13 In one embodiment, the wearable sweat glucose sensor device proposed in the present invention includes a flexible substrate 500, and a wireless charging circuit 100, an electrical storage device 300, a control circuit board 200 and a glucose sensor 400 arranged on the flexible substrate 500.

[0183] The wireless charging circuit 100 and the electrical storage device 300 are electrically connected to the control circuit board 200 respectively, and the control circuit board 200 is electrically connected to the glucose sensor 400; the control circuit board 200 is used to connect the wireless charging circuit 100 or the electrical storage device 300 to power the glucose sensor 400, and monitor the voltage changes of the wireless charging circuit 100 and the electrical storage device 300.

[0184] In this embodiment, the specific designs of the wireless charging circuit 100, the control circuit board 200 and the electrical storage device 300 refer to the aforementioned embodiments of the wireless charging circuit and the hybrid power supply device. The beneficial effects that can be achieved by the aforementioned embodiments can also be achieved by this embodiment, and will not be elaborated here.

[0185] In this embodiment, the glucose sensor 400 can be prepared by the aforementioned embodiment of the glucose sensor preparation method, which will not be described in detail here.

[0186] In this embodiment, the flexible substrate 500 needs to have certain flexibility, biocompatibility and air permeability, and the material of the flexible substrate 500 can be polydimethylsiloxane (PDMS), polyimide (PI) or polyurethane (PU).

[0187] In this embodiment, the wearable sweat glucose sensor device detects the glucose concentration in sweat through the glucose sensor 400 under power-on conditions and generates a corresponding electrical signal. Since the glucose concentration in sweat is usually lower than that in blood and is affected by many factors, such as exercise, diet, ambient temperature, etc., it is necessary to improve the sensitivity and selectivity of the glucose sensor and reduce the influence of interference factors. The glucose sensor prepared by the aforementioned preparation method in this embodiment has the advantages of high sensitivity, high specificity and in-situ analysis; the aforementioned wireless charging circuit and hybrid power supply device are used to solve the problem that the traditional wearable glucose sensor device has a single power supply, unstable power supply and cannot be monitored for a long time; in addition, the use of flexible materials makes the wearable sweat glucose sensor device easy to bend, stretch or compress to fit the human skin, providing a more convenient, comfortable and non-invasive blood glucose monitoring method for patients with glucose metabolism-related diseases.

[0188] It can be seen from all the above embodiments that the present invention, based on the current research status of flexible wearable sweat glucose sensors, proposes a wireless charging circuit and a hybrid power supply device, which can use the radio frequency energy in the environment to efficiently power electronic devices such as glucose sensors, make up for the singleness of the power supply of the electrical storage device, and achieve long-term and seamless power supply; the present invention also proposes a method for preparing a glucose sensor, by constructing a molecular imprinted polymer that can specifically identify glucose, introducing a MXene-AuNPs modification layer, AuNPs-doped molecular imprinted polymer, and embedding the redox probe Prussian blue, to prepare a new glucose sensor with the advantages of high sensitivity, high specificity and in-situ analysis; the wearable sweat glucose sensor device constructed based on the above technical solution can achieve all the advantages of the above technical solution, and is of great significance for the prevention, diagnosis, monitoring and research of diseases related to glucose metabolism.

[0189] In addition, the wireless charging circuit and hybrid power supply device proposed in the present invention are also suitable for powering a variety of other electronic devices; the glucose sensor prepared by the glucose sensor preparation method proposed in the present invention can also be used in various application scenarios that require glucose detection, such as food industry, environmental monitoring, and biomedical research; the aforementioned embodiments have provided illustrative descriptions of some of these applications, and it should be understood that these electronic devices, glucose sensors, and applications based on the embodiments of the present invention also fall within the scope of the technical solution of the present invention.

[0190] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A wireless charging circuit, characterized in that: include: A receiving antenna, a matching network, a rectifier circuit, a low-pass filter and an energy storage element electrically connected in sequence; The receiving antenna is used to receive radio frequency energy in the environment, and the radio frequency energy is converted into direct current energy after being processed by the matching network, the rectifier circuit, and the low-pass filter and stored in the energy storage element; The matching network includes a first capacitor, a first microstrip line and a second microstrip line; The first end of the first capacitor is electrically connected to the receiving antenna, and the second end is electrically connected to the first end of the first microstrip line; the second end of the first microstrip line is electrically connected to the rectifier circuit; the second microstrip line is connected in parallel to the first capacitor; the matching network is used to transmit the radio frequency energy received by the receiving antenna to the rectifier circuit at maximum power; The rectifier circuit includes a second capacitor, a third capacitor, a first diode and a second diode; The first end of the second capacitor is electrically connected to the second end of the first microstrip line, and the second end is electrically connected to the anode of the second diode; the cathode of the second diode is electrically connected to the low-pass filter; the first end of the third capacitor is electrically connected to the cathode of the second diode, and the second end is grounded; the cathode of the first diode is electrically connected to the second end of the second capacitor, and the anode is electrically connected to the second end of the third capacitor.

2. The wireless charging circuit according to claim 1, characterized in that: The low-pass filter includes a third diode, a fourth diode, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line and a seventh microstrip line; The anode of the fourth diode is electrically connected to the cathode of the second diode, and the cathode is electrically connected to the first end of the seventh microstrip line; the second end of the seventh microstrip line is electrically connected to the energy storage element; The cathode of the third diode is electrically connected to the anode of the fourth diode, and the anode is grounded; The third microstrip line, the fourth microstrip line, the fifth microstrip line and the sixth microstrip line are open stubs; wherein the first end of the third microstrip line and the first end of the fourth microstrip line are connected in parallel to the first end of the seventh microstrip line, and the second end of the third microstrip line and the second end of the fourth microstrip line are open; the first end of the fifth microstrip line and the first end of the sixth microstrip line are connected in parallel to the second end of the seventh microstrip line, and the second end of the fifth microstrip line and the second end of the sixth microstrip line are open.

3. A hybrid power supply device, characterized in that: It comprises a control circuit board, an electric storage device, and the wireless charging circuit according to claim 1 or 2; The control circuit board is electrically connected to the energy storage element in the wireless charging circuit, and is used to connect the wireless charging circuit to power an external device; The control circuit board is also electrically connected to the electrical storage device, and is used to connect the electrical storage device to supply power to the external device; The control circuit board is also used to monitor voltage changes of the wireless charging circuit and the electric storage device; when the output voltage of the electric storage device is less than a preset voltage threshold, the control circuit board switches to the wireless charging circuit to power the external device; or, when the output voltage of the wireless charging circuit is less than a preset voltage threshold, the control circuit board switches to the electric storage device to power the external device.

4. An electronic device, characterized in that: It comprises a working device and the hybrid power supply device according to claim 3; the hybrid power supply device is used to supply power to the working device; The working device is at least one of a sensor, a microcontroller, and an implantable medical device.

5. A method for preparing a glucose sensor, for preparing the sensor as claimed in claim 4, characterized in that: The preparation method comprises the following steps: S1, preparation of MXene-AuNPs modified electrode: dripping MXene-AuNPs aqueous solution on the surface of printed carbon electrode, drying in a vacuum oven, and then dripping perfluorosulfonic acid membrane solution on the electrode surface; S2, preparation of molecular imprinting polymerization precursor solution: preparing a phosphate buffer solution containing glucose, 3-hydroxyphenylboronic acid, catechol, chloroauric acid trihydrate, ferric chloride, potassium ferrocyanide, potassium chloride, and hydrochloric acid; S3, preparing AuNPs-doped molecularly imprinted polymer by electropolymerization: immersing the MXene-AuNPs modified electrode obtained in step S1 into the molecularly imprinted polymer precursor solution prepared in step S2, and performing electropolymerization by cyclic voltammetry; S4, eluting the template molecule: using cyclic voltammetry to elute the template molecule glucose in the molecularly imprinted polymer prepared in step S3 to obtain a working electrode for the glucose sensor.

6. The preparation method according to claim 5, characterized in that: In the step S1, the amount of the MXene-AuNPs aqueous solution added is 2-8 mL, the drying temperature of the vacuum oven is 60° C.; the concentration of the perfluorosulfonic acid membrane solution is 0.05 wt %, and the amount of the solution added is 2-5 mL; Wherein, the preparation method of the MXene-AuNPs aqueous solution is as follows: Mix 5-10 mg / mL MXene and 0.02-0.06 mg / mL AuNPs at a volume ratio of 1:1-1:30, and stir at room temperature for 10-15 hours to obtain a mixed solution of MXene and AuNPs; The mixed solution of MXene and AuNPs was centrifuged at 15000 rpm for 15-30 minutes, the supernatant was removed, and the product was washed twice with ultrapure water, the centrifugation step was repeated, and the product was dried in a vacuum oven at 60 °C to finally obtain powdered MXene-AuNPs; Powdered MXene-AuNPs were dispersed in ultrapure water to prepare a 0.5-2 mg / mL MXene-AuNPs aqueous solution.

7. The preparation method according to claim 5, characterized in that: In step S2, the molecular imprinting polymerization precursor solution is a phosphate buffer solution with a pH of 7.4 containing 1-8 mM glucose, 5-20 mM 3-hydroxyphenylboronic acid, 10-30 mM catechol, 0.1-0.6 mM chloroauric acid trihydrate, 3-20 mM ferric chloride, 3-20 mM potassium ferrocyanide, 0.1-0.3 M potassium chloride, 0.1-0.3 M hydrochloric acid, and 0.01-0.3 M phosphate.

8. The preparation method according to claim 7, characterized in that: In the step S3, the voltage range of the electropolymerization is -0.9-1.0 V, the scanning speed is 25-100 mV / s, and the number of scanning circles is 5-20 circles; In step S4, the voltage range for eluting the template molecules is -0.9-1.0 V, the scanning speed is 25-100 mV / s, and the number of scanning circles is 5-20 circles.

9. A glucose sensor, characterized in that: The invention comprises a sensor substrate, and a reference electrode, a counter electrode and a working electrode of a glucose sensor prepared by the preparation method according to any one of claims 5 to 8, which are arranged on the sensor substrate.

10. A wearable sweat glucose sensor device, characterized in that: Comprising a flexible substrate, and the hybrid power supply device according to claim 3 and the glucose sensor according to claim 9; The control circuit board of the hybrid power supply device is electrically connected to the glucose sensor, and the hybrid power supply device is used to supply power to the glucose sensor; the hybrid power supply device and the glucose sensor are both arranged on the flexible substrate.

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