A flexible smart patch and method for in situ monitoring of wound bacteria

Abstract

The application discloses a flexible intelligent patch and method for in-situ monitoring of wound bacteria. The patch comprises a packaging adhesive layer, a control circuit, an electrode array and a wound exudate absorption layer. The control circuit and the electrode array are electrically connected through the electrode array connection pad to form a combined planar structure, which is embedded in the packaging adhesive layer. The wound exudate absorption layer is fixed to the lower surface of the electrode array package. The electrode array comprises a staphylococcus aureus transpeptidase sensing electrode and a pyocyanin sensing electrode. The application utilizes a near field communication module to realize wireless power supply and data interaction through a mobile terminal, and adopts an electrochemical analysis method to realize in-situ real-time measurement of wound exudate, so as to realize simultaneous monitoring of the infection conditions of staphylococcus aureus and pseudomonas aeruginosa in the wound. The patch provides an instant detection platform for the management of infected wounds, and has the advantages of flexible intelligence, real-time in-situ and convenient operation.

Description

Technical Field

[0001] This invention relates to the field of in situ bacterial monitoring technology in wounds, and more particularly to a flexible smart patch and method for in situ bacterial monitoring in wounds. Background Technology

[0002] Open wounds such as ulcers, burns, and surgical incisions can become infected after being colonized by pathogenic bacteria, leading to wound deterioration and difficulty in healing. Wound infections are characterized by persistent pain, redness, swelling, and odor. If left untreated, they can easily spread and cause serious complications such as chronic wounds, bone infections, and sepsis. Because different bacteria exhibit varying levels of drug resistance, assessing and identifying the type of bacteria infecting the wound is a prerequisite for developing an effective wound treatment strategy. Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa are the two most common bacteria in infected wounds. Current clinical microbiological assessment of wound infections still relies on bacterial culture from wound swabs or biopsy samples. This method is highly invasive, time-consuming, complex, and dependent on specialized laboratories, failing to provide timely information on bacterial infection and impacting the wound healing process. Traditional wound patches or dressings mostly only function to protect the wound or deliver medication, failing to provide information about the wound infection status. Although some studies have reported on detecting wound conditions by integrating sensors into wound dressings, the detection indicators are still limited to indirect indicators such as temperature, pH, and uric acid, and the information they can provide about bacterial infection is very limited. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a flexible smart patch and method for in-situ monitoring of bacteria in wounds, thereby solving the problem of early, rapid, and real-time monitoring of bacterial infections in wounds.

[0004] The objective of this invention is achieved through the following technical solution: An embodiment of this invention provides a flexible smart patch for in-situ monitoring of bacteria in wounds, comprising: an encapsulation adhesion layer, a control circuit, an electrode array, and a wound exudate absorption layer;

[0005] The control circuit includes a circuit substrate, a near-field communication coil, a near-field communication chip, a digital-to-analog conversion module, an analog-to-digital conversion module, a microcontroller minimum system, a first potentiostat module, a second potentiostat module, and an electrode array assembly area.

[0006] The electrode array includes a first pair of electrodes, a first working electrode, a second pair of electrodes, a reference electrode, a second working electrode, an electrode array package, a serpentine connecting wire, an electrode array substrate, and electrode array connecting pads; the first pair of electrodes, the first working electrode, and the reference electrode constitute a Staphylococcus aureus transpeptidase sensing electrode; the second pair of electrodes, the second working electrode, and the reference electrode constitute a Pseudomonas aeruginosa sensing electrode.

[0007] The control circuit and the electrode array are electrically connected through the electrode array connection pads to form a combined planar structure, which is embedded together in the encapsulation adhesive layer.

[0008] The wound exudate absorption layer is fixed to the lower surface of the electrode array encapsulation of the electrode array.

[0009] Furthermore, the resonant frequency of the near-field communication coil is 13.56±2.00MHz. Through inductive coupling under an electromagnetic field, energy can be wirelessly transmitted from a mobile terminal with near-field communication function to the patched near-field communication coil.

[0010] Furthermore, both the first pair of electrodes and the second pair of electrodes contain the same three-layer material, wherein the first layer is polyimide, the second layer is conductive copper, and the third layer is conductive carbon ink.

[0011] The reference electrode comprises three layers of material, wherein the first layer is polyimide, the second layer is conductive copper, and the third layer is silver / silver chloride conductive ink.

[0012] The first working electrode comprises six layers of material, wherein the first layer is polyimide, the second layer is conductive copper, the third layer is a first carbon substrate layer, the fourth layer is a first MXene modification layer, the fifth layer is a gold nanoparticle modification layer, and the sixth layer is a peptide modification layer.

[0013] The second working electrode comprises four layers of material, wherein the first layer is polyimide, the second layer is conductive copper, the third layer is a second carbon substrate layer, and the fourth layer is a second MXene modification layer.

[0014] Furthermore, the first MXene-modified layer is prepared by a single layer of Ti3AlC2 MXene using a drop-coating method, that is, 5μL of Ti3AlC2 MXene aqueous solution with a concentration of 0.15mg / ml is dropped onto the working electrode and dried in an oven at 80°C for 5 minutes to remove moisture.

[0015] Furthermore, the gold nanoparticle modification layer is deposited using the self-reduction method of MXene in chloroauric acid solution. Specifically, 100 μL of chloroauric acid aqueous solution with a concentration of 0.1% is dropped onto the surface of the first MXene modification layer, and the surface is gently rinsed with deionized water after 5 minutes to complete the deposition of gold nanoparticles.

[0016] Furthermore, the peptide-modified layer is fabricated through the self-assembly of a specific peptide and gold-sulfur bonds. The specific peptide has the sequence "ferrocene-leucine-proline-glutamic acid-threonine-glycine-cysteine," and is synthesized using a solid-phase synthesis method, with each molecule linked by an amide bond. 100 μL of a specific peptide solution containing 5 mM tri-(2-formylethyl)phosphonic acid hydrochloride at a concentration of 0.1 mg / mL is dropped onto the surface of the fabricated gold nanoparticle-modified layer. The layer is incubated at 4°C in the dark for 12 hours, allowing the specific peptide to link to the gold nanoparticles via gold-sulfur bonds. After incubation, the electrode surface is gently rinsed with deionized water. 100 μL of a 1 mM 6-mercapto-1-hexanol solution is then added to the electrode surface and incubated at 4°C in the dark for 1 hour, linking other gold nanoparticles not bound to the specific peptide. After incubation, the electrode surface is gently rinsed with deionized water, completing the fabrication of the peptide-modified layer.

[0017] Furthermore, the second MXene-modified layer is prepared by a single layer of Ti3AlC2 MXene using a drop-coating method, that is, 5μL of Ti3AlC2 MXene aqueous solution with a concentration of 0.15mg / ml is dropped onto the working electrode and dried at 80°C for 5 minutes to remove moisture.

[0018] Furthermore, the parameters for differential pulse voltammetry used to detect Staphylococcus aureus transpeptidase include a pulse amplitude of 50 mV, a pulse width of 60 ms, a sampling width of 20 ms, a potential increment of 4 mV, and a scan voltage range of 0.1 V–0.5 V; the parameters for differential pulse voltammetry used to detect Pyrosisin include a pulse amplitude of 50 mV, a pulse width of 60 ms, a sampling width of 20 ms, a potential increment of 4 mV, and a scan voltage range of -0.45 V–0 V.

[0019] This invention also provides a method for assembling a flexible smart patch for in-situ bacterial monitoring in wounds, comprising the following steps:

[0020] Fabrication of control circuits and electrode arrays;

[0021] The completed electrode array is then assembled into the electrode array assembly area of ​​the control circuit.

[0022] A polyurethane film is used to encapsulate it, forming an encapsulation adhesion layer;

[0023] A sponge material with a thickness of less than 0.5 mm is fixed to the lower surface of the electrode array package to complete the assembly of the flexible smart patch.

[0024] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention provides a flexible smart patch and method for in-situ monitoring of bacteria in wounds, enabling real-time detection of Staphylococcus aureus transpeptidase and Pseudomonas aeruginosa pyocyanin in wounds. By integrating highly sensitive Staphylococcus aureus transpeptidase sensing electrodes and Pseudomonas aeruginosa sensing electrodes into the wound patch, the flexible smart patch proposed in this invention can effectively achieve rapid, real-time, and in-situ detection of the progression of bacterial infection in wounds. When infecting bacteria grow on the wound surface, the flexible smart patch can reflect the presence of Staphylococcus aureus and Pseudomonas aeruginosa in the wound environment and transmit the data to a mobile terminal. The mobile terminal will display the detection results and issue a wound infection alert. The flexible smart patch is convenient to operate and use, and is not limited by the user or the location of use. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the flexible smart patch structure provided in the embodiments of the present invention;

[0027] Figure 2 This is a schematic diagram of the flexible intelligent patch control circuit provided in the embodiments of the present invention;

[0028] Figure 3 These are screenshots of smartphone application software interfaces provided in embodiments of the present invention;

[0029] Figure 4 This is a diagram of the flexible smart patch functional module provided in the embodiments of the present invention;

[0030] Figure 5 This is a graph showing the relationship between the output voltage of the near-field communication module of the control circuit provided in the embodiments of the present invention and the distance between the smartphone and the control circuit;

[0031] Figure 6 This is a graph showing the relationship between the output voltage of the near-field communication module of the control circuit and the radius of curvature of the control circuit as provided in the embodiments of the present invention.

[0032] Figure 7 This is a schematic diagram of the flexible smart patch electrode array structure provided in the embodiments of the present invention;

[0033] Figure 8 This is a schematic diagram of the cyclic voltammetry characterization curves of the MXene / gold nanoparticle modified electrode and the bare electrode against the ferrocene probe provided in the embodiments of the present invention;

[0034] Figure 9This is a high-performance liquid chromatography characterization chromatogram of the Staphylococcus aureus transpeptidase electrode-modified polypeptide provided in the embodiments of the present invention;

[0035] Figure 10 This is a mass spectrometry characterization diagram of the Staphylococcus aureus transpeptidase electrode-modified polypeptide provided in the embodiments of the present invention;

[0036] Figure 11 This is a schematic diagram of the cyclic voltammetry characterization curves of the MXene-modified electrode and the bare electrode against pyocyanin provided in the embodiments of the present invention;

[0037] Figure 12 This is a response curve of the Staphylococcus aureus transpeptidase sensing electrode provided in the embodiments of the present invention to different concentrations of Staphylococcus aureus transpeptidase;

[0038] Figure 13 This is a linear fitting curve of the Staphylococcus aureus transpeptidase sensing electrode provided in the embodiments of the present invention for Staphylococcus aureus transpeptidase;

[0039] Figure 14 This is a response curve of the pyocyanin sensing electrode provided in the embodiments of the present invention for different concentrations of pyocyanin;

[0040] Figure 15 This is a linear fitting curve of the pyocyanin sensing electrode provided in the embodiments of the present invention for pyocyanin;

[0041] Figure 16 This is a graph showing the electrode array response results obtained from the spiking test of Staphylococcus aureus transpeptidase in a rat wound model using the flexible smart patch provided in this embodiment of the invention.

[0042] Figure 17 This is a graph showing the electrode array response results obtained from the Pseudomonas aeruginosa spiking test of the flexible smart patch provided in the embodiments of the present invention in a rat wound model;

[0043] Figure 18 This is a graph showing the electrode array response results obtained from the spiking of Pseudomonas aeruginosa and Staphylococcus aureus transpeptidase in a rat wound model using the flexible smart patch provided in this embodiment of the invention.

[0044] In the diagram: 1. Encapsulation adhesion layer; 2. Control circuit; 3. Electrode array; 4. Wound exudate absorption layer; 5. Mobile terminal application software; 6. Circuit substrate; 7. Near-field communication coil; 8. Near-field communication chip; 9. Digital-to-analog conversion module; 10. Analog-to-digital conversion module; 11. Microcontroller minimum system; 22. First potentiostat module; 23. Second potentiostat module; 24. Electrode array assembly area; 35. First pair of electrodes; 36. First working electrode; 37. Second pair of electrodes; 38. Reference electrode; 39. Second working electrode; 30. Electrode array encapsulation; 31. Serpentine connecting wire; 32. Electrode array substrate; 33. Electrode array connecting pad; 4. First carbon substrate layer; 5. First MXene modification layer; 6. Gold nanoparticle modification layer; 7. Peptide modification layer; 8. Second carbon substrate layer; 9. Second MXene modification layer. Detailed Implementation

[0045] The embodiments, features, and aspects of this disclosure will be described in detail below with reference to the accompanying drawings, but this is not intended to limit the invention. All other embodiments obtained by those skilled in the art based on any extension of the embodiments of this invention, without inventive effort, are within the scope of protection of this invention. The same reference numerals in the drawings denote the same or similar functional elements. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0046] In addition, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art should understand that this disclosure can be implemented without certain specific details. Some methods and means well known to those skilled in the art, as well as the use of components, are not described in detail in order to highlight the main points of this disclosure.

[0047] like Figure 1 As shown, this embodiment of the invention provides a flexible smart patch for in-situ monitoring of bacteria in wounds, comprising: an encapsulation adhesion layer 1, a control circuit 2, an electrode array 3, and a wound exudate absorption layer 4. The control circuit 2 and the electrode array 3 are electrically connected via electrode array connection pads 39, forming a combined planar structure, which is embedded together in the encapsulation adhesion layer 1. The wound exudate absorption layer 4 is fixed to the lower surface of the electrode array encapsulation 36 of the electrode array 3.

[0048] like Figure 2As shown, the control circuit 2 adopts a functional partition design and is fabricated using flexible printed circuit technology. It includes a circuit substrate 21, a near-field communication coil 22, a near-field communication chip 23, a digital-to-analog converter module 24, an analog-to-digital converter module 25, a microcontroller minimum system 26, a first potentiostat module 27, a second potentiostat module 28, and an electrode array assembly area 29. The near-field communication coil 22 is located in the outermost ring of the control circuit 2; the near-field communication chip 23, digital-to-analog converter module 24, analog-to-digital converter module 25, microcontroller minimum system 26, first potentiostat module 27, and second potentiostat module 28 are located in the left half of the inner ring of the control circuit 2, and the electronic components are surface-mounted onto the circuit substrate 21; the electrode array assembly area 29 is located in the right half of the inner ring of the control circuit 2, and is formed by laser engraving to create the electrode array assembly area.

[0049] In this example, the circuit substrate 21 uses flexible polyimide material. The near-field communication coil 22 and the near-field communication chip 23 together constitute the near-field communication module. The near-field communication coil 22 has a resonant frequency of 13.56±2.00MHz. Through inductive coupling under an electromagnetic field, energy can be wirelessly transmitted from a mobile terminal with near-field communication functionality to the patch-mounted near-field communication coil 22. The near-field communication chip 23 can be an NXP NT3H2111 chip. The energy obtained by the near-field communication coil 22 is modulated by the near-field communication chip 23 to obtain a stable voltage output as the system power supply. The digital / analog conversion module 24 can be constructed using a Texas Instruments DAC8564 chip as the main component. The analog / digital conversion module 25 can be constructed using a Texas Instruments ADS1115 chip as the main component. The microcontroller minimum system 26 can be constructed using a Texas Instruments MSP430FR2632 chip as the main component. The first potentiostat module 27 and the second potentiostat module 28 can each be constructed using Analog Devices' AD8608 chip as the main component.

[0050] like Figure 3 As shown, the mobile terminal application software 5 can establish a data connection with the flexible smart patch through the near-field communication coil 22 and the near-field communication chip 23, and output commands and display data. It can analyze and process the concentration information of Staphylococcus aureus transpeptidase and Pseudomonas aeruginosa pyocyanin received in real time, and display it for easy reading by the user.

[0051] In one possible implementation, the mobile terminal application software 5, which runs on the Android platform of a smartphone, is developed using the Android Studio development tool.

[0052] like Figure 4As shown, after the mobile terminal application software 5 connects to the near-field communication coil 22, it performs wireless energy and data transmission through the near-field communication coil 22. After modulation by the near-field communication chip 23, the data is transmitted to the microcontroller minimum system 26. After the microcontroller minimum system 26 starts working, it sends instructions to the digital-to-analog conversion module 24 and the analog-to-digital conversion module 25 respectively. After receiving the instructions, the digital-to-analog conversion module 24 sends electrical excitation signals to the first potentiostat module 27 and the second potentiostat module 28. It uses the electrochemical differential pulse voltammetry method to detect Staphylococcus aureus transpeptidase and Pseudomonas aeruginosa pyocyanin through electrodes, respectively. The detected signals are transmitted back to the analog-to-digital conversion module 25. The analog-to-digital conversion module 25 converts the received analog signals into digital signals and transmits them back to the microcontroller minimum system 26. The signals are then transmitted to the mobile terminal application software 5 for data processing and display. The differential pulse voltammetry parameters for detecting Staphylococcus aureus transpeptidase include a pulse amplitude of 50 mV, a pulse width of 60 ms, a sampling width of 20 ms, a potential increment of 4 mV, and a scan voltage range of 0.1 V-0.5 V; the parameters for detecting Pyrrosinase include a pulse amplitude of 50 mV, a pulse width of 60 ms, a sampling width of 20 ms, a potential increment of 4 mV, and a scan voltage range of -0.45 V-0 V.

[0053] As can be seen from the above embodiments, the flexible smart patch in this application can be powered by a mobile terminal. For example... Figure 5 As shown, when the mobile terminal smartphone and the control circuit 2 are kept within a certain distance, the output voltage obtained by the near-field communication module of the control circuit 2 from the mobile terminal smartphone can remain stable. When the distance between the smartphone and the wound patch is within 27.5mm, the voltage output by the near-field communication module is stable at around 2.6V. This indicates that when the smartphone and the wound patch are within 27.5mm, they can normally supply power and communicate with the flexible smart patch.

[0054] As can be seen from the above embodiments, the flexible smart patch in this application has a certain deformation capability. For example... Figure 6 As shown, when the bending degree of control circuit 2 is kept within a certain range, the output voltage obtained by the near-field communication module of control circuit 2 from the mobile terminal smartphone can remain stable. When the wound patch gradually bends from the plane to a radius of curvature of 1cm, the voltage output by the near-field communication module stabilizes at around 2.6V, which indicates that the bending of the flexible smart patch does not affect its power supply and communication through the near-field communication module.

[0055] like Figure 7As shown, the electrode array 3 includes a first pair of electrodes 31, a first working electrode 32, a second pair of electrodes 33, a reference electrode 34, a second working electrode 35, an electrode array package 36, a serpentine connecting wire 37, an electrode array substrate 38, and electrode array connecting pads 39. The serpentine connecting wire 37, the electrode array substrate 38, and the electrode array connecting pads 39 are fabricated using flexible printed circuit technology and constructed using laser engraving technology. The serpentine connecting wire 37 uses copper material with double-sided polyimide coating. The electrode array substrate 38 uses flexible polyimide material. The electrode array connecting pads 39 use copper material. The electrode array package 36 uses polydimethylsiloxane material, covering the upper and lower layers of the electrode array 3, excluding the areas of the first pair of electrodes 31, the first working electrode 32, the second pair of electrodes 33, the reference electrode 34, the second working electrode 35, and the electrode array connecting pads 39.

[0056] Both the first pair of electrodes 31 and the second pair of electrodes 33 contain the same three-layer material: the first layer is polyimide, the second layer is conductive copper, and the third layer is conductive carbon ink. They are manufactured using flexible printed circuit processing technology and screen printing electrode technology.

[0057] The reference electrode 34 comprises three layers: the first layer is polyimide, the second layer is conductive copper, and the third layer is silver / silver chloride conductive ink. It is manufactured using flexible printed circuit processing technology and screen printing electrode technology.

[0058] The first working electrode 32 comprises six layers: a first layer of polyimide, a second layer of conductive copper, a third layer of a first carbon substrate 321, a fourth layer of a first MXene modification layer 322, a fifth layer of gold nanoparticle modification layer 323, and a sixth layer of peptide modification layer 324. The first to third layers are fabricated using flexible printed circuit technology and screen printing electrode technology, while the fourth to sixth layers are fabricated using biochemical modification methods.

[0059] The first MXene-modified layer 322 is made of a single layer of Ti3AlC2 MXene by drop coating, that is, 5μL of Ti3AlC2 MXene aqueous solution with a concentration of 0.15mg / ml is dropped onto the working electrode and dried in an oven at 80℃ for 5 minutes to remove moisture.

[0060] The gold nanoparticle modification layer 323 is deposited using the self-reduction method of MXene in chloroauric acid solution. Specifically, 100 μL of chloroauric acid aqueous solution with a concentration of 0.1% is dropped onto the surface of the first MXene modification layer 322 after it has been made. After 5 minutes, the surface is gently rinsed with deionized water to complete the deposition of gold nanoparticles.

[0061] The first MXene modification layer 322 and the gold nanoparticle modification layer 323 are designed to improve the sensing performance of the first working electrode 32 for the ferrocene probe. Cyclic voltammetry was used to verify this performance improvement. Cyclic voltammetry scans were performed on the working electrode (also known as the bare electrode) after the first to third layers were fabricated, and on the working electrode (also known as the MXene / gold nanoparticle modified electrode) after the first to fifth layers were fabricated, in a 100 μM ferrocene acetate probe solution. An increase in peak current was observed. Figure 8 As shown, it is confirmed that after the fabrication of the first MXene modification layer 322 and the nano-gold particle modification layer 323, the sensing performance of the working electrode is improved, and the subsequent layer can be fabricated.

[0062] The polypeptide-modified layer 324 is fabricated through the self-assembly of a specific polypeptide and gold-sulfur bonds. The specific polypeptide has the sequence "ferrocene-leucine-proline-glutamic acid-threonine-glycine-cysteine," and is synthesized using a solid-phase synthesis method, with each molecule linked by an amide bond. Figure 9 As shown, the purity of the synthesized specific peptides was characterized by high-performance liquid chromatography (HPLC) to ensure a purity of over 95%. Figure 10 As shown, the molecular weight of the synthesized specific peptide was characterized by mass spectrometry, ensuring that the molecular weight was within the range of 844.77 ± 0.50. After ensuring that the synthesized specific peptide met the requirements, 100 μL of a specific peptide solution containing 5 mM tri-(2-formylethyl)phosphonic acid hydrochloride at a concentration of 0.1 mg / mL was dropped onto the surface of the prepared gold nanoparticle modification layer 323. The layer was incubated at 4°C in the dark for 12 hours to allow the specific peptide to be linked to the gold nanoparticles via gold-sulfur bonds. After incubation, the electrode surface was gently rinsed with deionized water. 100 μL of a 1 mM 6-mercapto-1-hexanol solution was then added to the electrode surface and incubated at 4°C in the dark for 1 hour to link other gold nanoparticles that were not bound to the specific peptide. After incubation, the electrode surface was gently rinsed with deionized water, completing the fabrication of the peptide modification layer 324.

[0063] The second working electrode 35 comprises four layers: the first layer is polyimide, the second layer is conductive copper, the third layer is a second carbon substrate layer 351, and the fourth layer is a second MXene modification layer 352. The first to third layers are fabricated using flexible printed circuit technology and screen printing electrode technology, while the fourth layer is fabricated using a biochemical modification method.

[0064] The second MXene-modified layer 352 is made of a single layer of Ti3AlC2 MXene by drop coating, that is, 5μL of Ti3AlC2 MXene aqueous solution with a concentration of 0.15mg / ml is dropped onto the working electrode and dried at 80°C for 5 minutes to remove moisture.

[0065] The second MXene-modified layer 352 is designed to improve the sensing performance of the second working electrode 35 for Pseudomonas aeruginosa. Cyclic voltammetry was used to verify this performance improvement. Cyclic voltammetry scans were performed on the working electrode (also known as the bare electrode) after the fabrication of the first to third layers and the working electrode (also known as the MXene-modified electrode) after the fabrication of the first to fourth layers in a 50 μM Pseudomonas aeruginosa solution. An increase in peak current was observed. Figure 11 As shown, the sensing performance of the working electrode is improved after the second MXene modification layer 352 is fabricated.

[0066] The Staphylococcus aureus transpeptidase sensing electrode consists of a first pair of electrodes 31, a first working electrode 32, and a reference electrode 34. The Pseudomonas aeruginosa sensing electrode consists of a second pair of electrodes 33, a second working electrode 35, and a reference electrode 34.

[0067] The flexible smart patch designed in this application can detect the concentration changes of Staphylococcus aureus transpeptidase from 1 pg / ml to 100 ng / ml in real time, and is calibrated before use. Artificial wound exudate was prepared by dissolving 124 mM sodium chloride, 831 μM magnesium chloride, 5 mM glucose, 150 μM albumin, and 1 μM lactate in deionized water and mixing thoroughly. Staphylococcus aureus transpeptidase solutions with concentrations of 1 pg / mL, 10 pg / mL, 100 pg / mL, 1 ng / mL, 10 ng / mL, and 100 ng / mL were prepared using the artificial wound exudate. Artificial wound exudate without Staphylococcus aureus transpeptidase (blank group) was added dropwise to the surface of the Staphylococcus aureus transpeptidase sensing electrode and incubated at 37°C for 10 minutes. The peak current of the differential pulse voltammetry curve was measured. A solution of Staphylococcus aureus transpeptidase of appropriate concentration was added dropwise to the surface of the Staphylococcus aureus transpeptidase sensing electrode and incubated at 37°C for 10 minutes. The peak current of the differential pulse voltammetry curve was then measured. Figure 12 As shown in the curves, the peak current of the differential pulse voltammetry curve decreases with increasing concentration of Staphylococcus aureus transpeptidase. The percentage change in signal between the test results of different concentrations of Staphylococcus aureus transpeptidase and the blank group was calculated. Figure 13 As shown, the percentage change in signal increases with the increase of Staphylococcus aureus transpeptidase concentration, and the linear regression coefficient is 0.9936, indicating that the Staphylococcus aureus transpeptidase sensing electrode has a good linear response to Staphylococcus aureus transpeptidase.

[0068] The flexible smart patch designed in this application can detect the concentration changes of Pseudomonas aeruginosa pyocyanin from 1μM to 100μM in real time, and is calibrated before use. Pyocyanin solutions with concentrations of 1μM, 10μM, 30μM, 50μM, 75μM, and 100μM were prepared using artificially simulated wound exudate. Artificially simulated wound exudate without pyocyanin (blank group) was dropped onto the surface of the pyocyanin sensing electrode, and the peak current of the differential pulse voltammetry curve was measured. Similarly, pyocyanin solutions of corresponding concentrations were dropped onto the surface of the pyocyanin sensing electrode, and the peak current of the differential pulse voltammetry curve was measured. Figure 14 As shown in the test result curve, the peak current of the differential pulse voltammetry curve increases with increasing concentration of pyocyanin. Figure 15 As shown, the peak current of the differential pulse voltammetry curve is linearly correlated with the concentration of pyocyanin, with a linear regression coefficient of 0.9985, indicating that the pyocyanin sensing electrode has a good linear response to pyocyanin.

[0069] The flexible smart patch designed in this application includes detection functions for Staphylococcus aureus transpeptidase and Pseudomonas aeruginosa pyocyanin, enabling simultaneous detection of these two substances in wounds. Figure 16 As shown, a flexible smart patch was attached to a rat wound model for Staphylococcus aureus transpeptidase spiking. Differential pulse voltammetry was performed on the wounds of the untreated control group and the experimental group wounds spiked with Staphylococcus aureus transpeptidase. The results showed that the Pseudomonas aeruginosa sensing electrode did not produce a response signal to Staphylococcus aureus transpeptidase, while the Staphylococcus aureus transpeptidase sensing electrode did produce a response signal. Figure 17 As shown, a flexible smart patch was attached to a rat wound model for Pseudomonas aeruginosa spiking test. Differential pulse voltammetry tests were performed on the wounds of the untreated control group and the experimental group with Pseudomonas aeruginosa spiking. The test results showed that the Pseudomonas aeruginosa sensing electrode responded to Pseudomonas aeruginosa, while the Staphylococcus aureus transpeptidase sensing electrode did not produce a response signal to Pseudomonas aeruginosa. Figure 18 As shown, a flexible smart patch was attached to a rat wound model for simultaneous spiked testing of pyocyanin and Staphylococcus aureus transpeptidase. Differential pulse voltammetry was performed on the wounds of the untreated control group and the experimental group wounds that were spiked with both pyocyanin and Staphylococcus aureus transpeptidase. The test results showed that the pyocyanin sensing electrode responded to pyocyanin, and the Staphylococcus aureus transpeptidase sensing electrode responded to Staphylococcus aureus transpeptidase.

[0070] This application also provides a method for assembling a flexible smart patch for in-situ bacterial monitoring of wounds as described above, including the following steps:

[0071] Fabricate control circuit 2 and electrode array 3;

[0072] The completed electrode array 3 is assembled into the electrode array assembly area 29 of the control circuit 2;

[0073] A polyurethane film is used to encapsulate it, forming an encapsulation adhesion layer 1;

[0074] A sponge material with a thickness of less than 0.5 mm is fixed to the lower surface of the electrode array package 36 of the electrode array 3 to complete the assembly of the flexible smart patch.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flexible smart patch for in-situ monitoring of bacteria in wounds, characterized in that, It includes: Encapsulation adhesive layer (1), control circuit (2), electrode array (3), wound exudate absorption layer (4); The control circuit (2) includes a circuit substrate (21), a near-field communication coil (22), a near-field communication chip (23), a digital-to-analog conversion module (24), an analog-to-digital conversion module (25), a single-chip microcomputer minimum system (26), a first potentiostat module (27), a second potentiostat module (28), and an electrode array assembly area (29). The electrode array (3) includes a first pair of electrodes (31), a first working electrode (32), a second pair of electrodes (33), a reference electrode (34), a second working electrode (35), an electrode array package (36), a serpentine connecting wire (37), an electrode array substrate (38), and an electrode array connecting pad (39); the first pair of electrodes (31), the first working electrode (32), and the reference electrode (34) constitute a Staphylococcus aureus transpeptidase sensing electrode; the second pair of electrodes (33), the second working electrode (35), and the reference electrode (34) constitute a Pseudomonas aeruginosa sensing electrode; The first pair of electrodes (31) and the second pair of electrodes (33) both contain the same three-layer material, wherein the first layer is polyimide, the second layer is conductive copper, and the third layer is conductive carbon ink; The reference electrode (34) comprises three layers of material, wherein the first layer is polyimide, the second layer is conductive copper, and the third layer is silver / silver chloride conductive ink; The first working electrode (32) comprises six layers of material, wherein the first layer is polyimide, the second layer is conductive copper, the third layer is a first carbon substrate layer (321), the fourth layer is a first MXene modification layer (322), the fifth layer is a gold nanoparticle modification layer (323), and the sixth layer is a polypeptide modification layer (324). The second working electrode (35) comprises four layers of material, wherein the first layer is polyimide, the second layer is conductive copper, the third layer is a second carbon substrate layer (351), and the fourth layer is a second MXene modification layer (352). The first MXene modified layer (322) and the second MXene modified layer (352) are fabricated using a single layer of Ti3AlC2 MXene via drop-coating. The polypeptide-modified layer (324) is prepared by synthesizing a specific polypeptide and self-assembling gold-sulfur bonds; wherein, the sequence of the specific polypeptide is "ferrocene-leucine-proline-glutamic acid-threonine-glycine-cysteine", which is synthesized by solid-phase synthesis, and each molecule is connected by an amide bond. The control circuit (2) and the electrode array (3) are electrically connected through the electrode array connection pad (39) to form a combined planar structure, which is embedded together in the encapsulation adhesive layer (1); The wound exudate absorption layer (4) is fixed on the lower surface of the electrode array package (36) of the electrode array (3).

2. The flexible smart patch for in-situ bacterial monitoring in wounds according to claim 1, characterized in that, The resonant frequency of the near-field communication coil (22) is 13.56±2.00MHz. Through inductive coupling under electromagnetic field, energy is wirelessly transmitted from the mobile terminal with near-field communication function to the patch near-field communication coil (22).

3. The flexible smart patch for in-situ bacterial monitoring in wounds according to claim 1, characterized in that, The first MXene modified layer (322) is made by drop coating of a single layer of Ti3AlC2 MXene, that is, 5μL of Ti3AlC2 MXene aqueous solution with a concentration of 0.15mg / ml is dropped onto the working electrode and dried in an oven at 80℃ for 5 minutes to remove moisture.

4. The flexible smart patch for in-situ bacterial monitoring in wounds according to claim 1, characterized in that, The gold nanoparticle modification layer (323) is deposited by the self-reduction method of MXene in chloroauric acid solution. Specifically, 100 μL of chloroauric acid aqueous solution with a concentration of 0.1% is dropped onto the surface of the first MXene modification layer (322) after it is made. After 5 minutes, the surface is gently rinsed with deionized water to complete the deposition of gold nanoparticles.

5. The flexible smart patch for in-situ bacterial monitoring in wounds according to claim 1, characterized in that, 100 μL of a specific peptide solution containing 5 mM tri-(2-formylethyl)phosphonic acid hydrochloride at a concentration of 0.1 mg / mL was dropped onto the surface of the prepared gold nanoparticle modified layer (323). The layer was incubated at 4 °C in the dark for 12 hours to allow the specific peptide to be linked to the gold nanoparticles via gold-sulfur bonds. After incubation, the electrode surface was gently rinsed with deionized water. 100 μL of a 1 mM 6-mercapto-1-hexanol solution was dropped onto the electrode surface and incubated at 4 °C in the dark for 1 hour to link other gold nanoparticles that were not bound to the specific peptide. After incubation, the electrode surface was gently rinsed with deionized water to complete the preparation of the peptide modified layer (324).

6. The flexible smart patch for in-situ bacterial monitoring in wounds according to claim 1, characterized in that, The second MXene modified layer (352) is made by drop coating of a single layer of Ti3AlC2 MXene, that is, 5μL of Ti3AlC2 MXene aqueous solution with a concentration of 0.15mg / ml is dropped onto the working electrode and dried at 80°C for 5 minutes to remove moisture.

7. The flexible smart patch for in-situ bacterial monitoring in wounds according to claim 1, characterized in that, The parameters for differential pulse voltammetry used to detect Staphylococcus aureus transpeptidase include a pulse amplitude of 50 mV, a pulse width of 60 ms, a sampling width of 20 ms, a potential increment of 4 mV, and a scan voltage range of 0.1 V - 0.5 V. The parameters for differential pulse voltammetry used to detect Pyrrosinase include a pulse amplitude of 50 mV, a pulse width of 60 ms, a sampling width of 20 ms, a potential increment of 4 mV, and a scan voltage range of -0.45 V - 0 V.

8. The assembly method of the flexible smart patch for in-situ bacterial monitoring in wounds according to any one of claims 1-7, characterized in that, Includes the following steps: Fabricate the control circuit (2) and the electrode array (3); The completed electrode array (3) is assembled into the electrode array assembly area (29) of the control circuit (2). A polyurethane film was used to encapsulate it to form an encapsulation adhesive layer (1). A sponge material with a thickness of less than 0.5 mm is fixed on the lower surface of the electrode array package (36) of the electrode array (3) to complete the assembly of the flexible smart patch.

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