Biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material and preparation of biosensor

Abstract

The thermoelectric material opens up a new way for self-power supply of microelectronic devices, and the combination with the sensor has been significantly developed. However, the application of the thermoelectric material in the field of biosensors is still challenged, which limits the potential of the thermoelectric material in exploring biochemical reactions and promoting the development of biosensors. The invention innovatively provides a detection method based on a silver selenide thermoelectric film, and efficient detection of hydrogen peroxide is realized through photo-thermal-thermoelectric conversion. Compared with a traditional method, the method is short in detection time, low in cost and easy and convenient to operate. Furthermore, the specific detection of streptococcus sanguis and methicillin-resistant staphylococcus aureus is realized by utilizing the characteristics of different bacteria, and a new guiding thought is provided for the diagnosis and treatment of diseases.

Description

Technical Field

[0001] This invention relates to a biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material and its preparation, belonging to the field of biosensing technology. Background Technology

[0002] Thermoelectric materials can convert heat energy into electrical energy through the Seebeck effect, achieving green energy conversion. This is highly advantageous for next-generation self-powered microelectronic devices, such as wireless sensors, wearable electronics, and flexible electronic devices. When a temperature gradient exists across a thermoelectric material, it leads to an asymmetric distribution of the electron transport gradient, thereby generating a thermoelectric voltage. Since the discovery of the Seebeck effect in the 19th century, thermoelectric materials have been used for temperature detection. In recent years, the emergence of numerous high-performance thermoelectric materials has opened up the potential for high-precision, sensitive sensors based on thermoelectric materials. The advent of high-performance room-temperature thermoelectric materials has further broadened their application in biosensing.

[0003] In recent years, numerous studies have demonstrated the potential of thermoelectric materials in the sensor field. For example, high-resolution temperature sensors, electronic skin arrays, high-performance dual-parameter sensors based on bismuth telluride thin films, and photothermal-thermoelectric biosensors have been developed. However, current research primarily focuses on the application of thermoelectric materials in electronic skin or temperature sensors, neglecting their potential applications in biosensors for detecting biomarkers or microorganisms, which limits the development of thermoelectric materials.

[0004] Accurate detection and measurement of reactive oxygen species, such as hydrogen peroxide, are crucial for clinical diagnosis and targeted therapy. Hydrogen peroxide is produced during cellular metabolism, and excess levels are associated with a variety of diseases. Monitoring hydrogen peroxide concentration is essential for understanding its role in health and disease. Emerging detection technologies have improved measurement sensitivity and specificity, but still face challenges such as high cost and time consumption. Thermoelectric materials, which convert the heat energy generated by chemical reactions into electrical signals, hold promise as ideal materials for rapid and sensitive measurement of hydrogen peroxide in biological samples, providing a foundation for the development of innovative, efficient, and accurate H2O2 biosensors. Summary of the Invention

[0005] This application provides a biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material and its preparation, in order to solve the problem that related technologies cannot detect biomarkers through thermoelectric materials and cannot use the thermal energy of chemical reactions for sensing signal detection, thereby further solving the problem that related technologies cannot quickly and conveniently detect bacteria such as hydrogen peroxide, streptococcus sanguinis and Staphylococcus aureus.

[0006] To achieve the above objectives, the present invention provides a biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material, and its preparation method comprises the following steps:

[0007] Step 1) Print 3D resin using a 3D printer.

[0008] Step 2) Prepare sodium sulfide-selenium solution. The method for preparing sodium sulfide-selenium solution is as follows: dissolve 0.6g of sodium sulfide nonahydrate in 20ml of double-distilled water. After complete dissolution, add 0.2g of selenium powder and stir evenly. The solution changes from colorless to dark red.

[0009] Step 2) Synthesis of silver selenide. Nanoparticles of silver were sputtered onto a 3D resin substrate using an ion sputtering apparatus, followed by a selenization reaction with a sodium sulfide-selenium solution to synthesize silver selenide. The parameters of the ion sputtering apparatus used for preparing a single sample were: current 20 mA, pressure 4 Pa, and time 1000 seconds. The thickness of the synthesized silver selenide was 200 nm.

[0010] Step 3) Connect the silver selenide film. Use conductive silver paste to connect the first and second ends of the silver selenide film to form a circuit. Finally, cover the device with a polyimide film as a protective layer.

[0011] This application provides a biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material and its fabrication. The biosensor structure includes a sensing layer comprising a silver selenide thin film and reference silver electrodes and sensing silver electrodes at both ends; a substrate layer formed on resin by the region where the sensing layer is synthesized, and a protective layer formed by a polyimide thin film covering the sensing layer. The sensing layer is used to sense external environmental stimuli, the substrate layer provides support for the sensing layer, and the protective layer provides protection for the sensing layer.

[0012] Optionally, in one embodiment of this application, the material of the substrate includes one or more of the following: resin, polydimethylsiloxane, polyethylene, polypropylene, polyvinylidene fluoride, perfluoroethylene propylene, vinylidene chloride acrylonitrile copolymer, polytetrafluoroethylene, polyvinyl chloride, polychlorotrifluoroethylene, polychloroprene, polyisobutylene, polyoxymethylene, polyamide, polyimide, melamine formaldehyde, polycarbonate, polyethylene glycol succinate, phenolic resin, aniline formaldehyde resin, chloroprene rubber, natural rubber, cellulose, ethyl cellulose, cellulose acetate, polyethylene adipate, diallyl phthalate, polyethanol butyral, styrene-propylene copolymer, styrene-butadiene copolymer, polyvinylpropene carbonate, polystyrene, polymethyl methacrylate, polyester, and polyurethane.

[0013] Optionally, in one embodiment of this application, the materials of the sensing electrode and the reference electrode include one or more of the following: gold, silver, platinum, palladium, aluminum, nickel, copper, titanium, chromium, selenium, iron, manganese, molybdenum, tungsten, or vanadium; aluminum alloys; titanium alloys; magnesium alloys; beryllium alloys; copper alloys; zinc alloys; manganese alloys; nickel alloys; lead alloys; tin alloys; cadmium alloys; bismuth alloys; indium alloys; gallium alloys; tungsten alloys; molybdenum alloys; niobium alloys; tantalum alloys; graphite; and conductive glass.

[0014] Optionally, in one embodiment of this application, the material of the thermoelectric induction layer includes inorganic thermoelectric materials such as silver selenide, silicon-germanium alloy, bismuth-antimony alloy, bismuth selenide, bismuth telluride, cadmium selenide, bismuth-antimony selenide, germanium-tin alloy, copper indium selenide, indium antimonide, bismuth indium selenide, and bismuth telluride; organic thermoelectric materials such as Pedot:PSS, polyaniline, polytriphenylamine, polyp-phenylenediamine, polythiophene, polyfluorene, polystyrene, polyacetylene, polypropyne, polymer fibers, and graphene; and hydrogel thermoelectric materials such as lithium-ion thermoelectric hydrogel, bismuth-ion thermoelectric hydrogel, sodium-ion thermoelectric hydrogel, manganese-ion thermoelectric hydrogel, vanadium-ion thermoelectric hydrogel, copper-ion thermoelectric hydrogel, iron-ion thermoelectric hydrogel, titanium-ion thermoelectric hydrogel, nickel-ion thermoelectric hydrogel, and iron-ion thermoelectric hydrogel.

[0015] Optionally, in one embodiment of this application, the material of the protective layer includes one or more of the following: polydimethylsiloxane, polyethylene, polypropylene, polyvinylidene fluoride, perfluoroethylene propylene, vinylidene chloride acrylonitrile copolymer, polytetrafluoroethylene, polyvinyl chloride, polychlorotrifluoroethylene, polychloroprene, polyisobutylene, polyoxymethylene, polyamide, polyimide, melamine formaldehyde, polycarbonate, polyethylene glycol succinate, phenolic resin, aniline formaldehyde resin, chloroprene rubber, natural rubber, cellulose, ethyl cellulose, cellulose acetate, polyethylene adipate, diallyl phthalate, polyethanol butyral, styrene-propylene copolymer, styrene-butadiene copolymer, polyvinylpyrrolidone carbonate, polystyrene, polymethacrylate, polyester, and polyurethane. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 This is a schematic diagram of the silver selenide thermoelectric sensor architecture. (a) Mechanism of hydrogen peroxide detection by the sensor. (b)-(d) Schematic diagram of sensor application. (e)-(g) Steps and principles of sensor operation.

[0018] Figure 2Characterization results of silver selenide thin films prepared on resin substrates. (a) XRD pattern of the silver selenide thin film; (b)-(c) XPS spectra of silver selenide; (d) SEM image of the silver selenide thin film on the resin substrate; (e) bright-field scanning transmission electron microscope (STEM) image and cross-sectional view of the silver selenide thin film on the resin substrate; (f) high-resolution STEM images of the cross-section of the silver selenide thin film on the resin substrate, showing the interface between silver selenide and resin; (g) high-angle annular dark-field imaging image of the silver selenide / resin interface; (h) component distribution of silver and selenium in the silver selenide thin film; (i) energy dispersive spectroscopy line scanning profile through the silver selenide layer, and the corresponding energy dispersive spectral spectra showing the components; (j) temperature-dependent thermoelectric properties of the silver selenide thin film; (k) voltage response of silver selenide thin films of different thicknesses.

[0019] Figure 3 Performance of the silver selenide thin film and sensor. (a) Fabrication process of the silver selenide thermoelectric biosensor. (b) UV-Vis spectra of ABTS at different concentrations of hydrogen peroxide. (c) Relationship between absorbance at 808 nm and hydrogen peroxide concentration (from 0 μM to 10 μM). Insets show images of ABTS at different concentrations of hydrogen peroxide. (d) Specificity of the sensor to hydrogen peroxide. (e) Voltage response curves of the biosensor to different concentrations of hydrogen peroxide. (f) Relationship between voltage difference over 60 seconds and hydrogen peroxide concentration (from 0 μM to 10 μM).

[0020] Figure 4 (a) Schematic diagram of the detection of Streptococcus spp. (b) Microscopic image of Streptococcus spp. (c) Scanning electron microscope image of Streptococcus spp. (d) Plate images of different concentrations of Streptococcus spp. (e) Reactive oxygen species (ROS) fluorescence intensity of different concentrations of Streptococcus spp. (f) 3D plot. (g) Average fluorescence intensity of different concentrations of Streptococcus spp. (h) Sensor detection of different concentrations of Streptococcus spp. (i) Kit detection of different concentrations of Streptococcus spp.

[0021] Figure 5 (a) Schematic diagram of the steps and principle of using a sensor to detect methicillin-resistant Staphylococcus aureus (MRSA); (b) Plate images of methicillin-resistant Staphylococcus aureus at different concentrations; (c) Microscopic morphology of methicillin-resistant Staphylococcus aureus observed by scanning electron microscopy after incubation with 10 μM hydrogen peroxide, as well as (d) and (e) three-dimensional images of reactive oxygen species (ROS) fluorescence intensity, and (f) average fluorescence intensity; (g) Sensor and (h) test results of the supernatant after incubation. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0023] Example 1: Synthesis and Identification of the Silver Selenide Thin Film Sensor of the Present Invention

[0024] 1. Principles and Applications of Silver Selenide Biosensors

[0025] Figure 1 The principles, architecture, and applications of silver selenide-based biosensors were demonstrated. Figure 1 The mechanism of the biosensor is explained in section a. In the presence of horseradish peroxidase (HRP), hydrogen peroxide can oxidize ABTS to generate ABTS radicals (ABTS·+). When excited by infrared light, ABTS·+ releases heat, creating a temperature gradient on the biosensor, which in turn generates a voltage signal via the Seebeck effect. The voltage output of the silver selenide-based biosensor is controlled by the generated temperature gradient, which is directly affected by the amount of ABTS·+ produced. Therefore, the voltage signal emitted by the silver selenide biosensor serves as a reliable indicator for quantifying the hydrogen peroxide concentration in a sample.

[0026] then, Figure 1 bd details the fabrication and working mechanism of a silver selenide-based biosensor based on a silver selenide thermoelectric thin film. A standard solution containing horseradish peroxidase (HRP) and ABTS (see [link to documentation]). Figure 1 f) After being mixed with a hydrogen peroxide solution of a certain concentration, the mixture is added to one side of the biosensor chamber. Then, a laser beam is perpendicularly irradiated onto the solution. The photothermal conversion of ABTS·+ causes the temperature inside the solution to rise, thereby creating a temperature difference on opposite sides of the biosensor. The induced thermal gradient on the silver selenide biosensor generates a voltage output through the Seebeck effect within the silver selenide sensing layer. This voltage output is proportional to the concentration of the hydrogen peroxide being measured.

[0027] Based on the above working principle Figure 1 eg demonstrates three specific applications of the x-silver selenide biosensor principle in the detection of hydrogen peroxide, including assessing the concentration of hydrogen peroxide in food samples and quantifying the bacterial concentrations of Streptococcus spp. and methicillin-resistant Staphylococcus aureus.

[0028] 2. Characterization and results of silver selenide thin films

[0029] To confirm the phase structure of the Ag₂Se film obtained on the PE substrate, we performed typical X-ray diffraction (XRD) analysis on the prepared silver selenide. The XRD patterns confirmed that the diffraction patterns of all films could be well indexed to β-Ag₂Se, referring to the Ag₂Se standard PDF card (PDF number 24-1041), and no diffraction peaks for silver were detected. This confirms that the obtained silver selenide film is pure and possesses polycrystalline properties. Figure 2 a). To further characterize the chemical properties of the obtained silver selenide film, we used X-ray photoelectron spectroscopy (XPS) to measure the overall XPS spectrum and the corresponding high-resolution XPS spectrum of the silver selenide sample, showing Ag 3d 3 / 2 Ag 3d 5 / 2 、Se 3d 3 / 2 and Se 3d 5 / 2 The peak value confirmed that the obtained membrane was pure silver selenide. Figure 2 b, c).

[0030] To demonstrate the morphology of the synthesized silver selenide film, we used scanning electron microscopy (SEM). Top and side SEM images of the silver selenide / resin film show that a homogeneous silver selenide film was obtained. Figure 2 d, e)

[0031] To further investigate the structural features of the silver selenide film and the underlying resin substrate, we used transmission electron microscopy (TEM) to observe cross-sections of a typical silver selenide film. Figure 2 f,) results show that it has a polycrystalline morphology.

[0032] High-resolution transmission electron microscopy (HRTEM) observations showed that silver selenide and the resin substrate could form a robust interface. Figure 2 h). The elemental mapping results further confirmed the uniform distribution of silver and selenium, and no impurities were observed. Figure 2 h,i).

[0033] We measured several key thermoelectric parameters of a 200 nm thick silver selenide film at different temperatures, including the Seebeck coefficient S and conductivity σ, and calculated PF = S. 2 σ obtained the power factor (PF) values ​​of silver selenide thin films of different thicknesses (e.g. Figure 2 (As shown in j). The response voltage curves of films of different thicknesses to objects at the same temperature are shown in... Figure 2 As shown in k, the results indicate that the 200 nm film has a shorter response time.

[0034] Example 2: Performance Testing of the Silver Selenide Thin Film Sensor of the Present Invention

[0035] 1. Synthesis and Assembly of Silver Selenide Sensors

[0036] 1.1 Synthesis of Silver Selenide Thin Films

[0037] A 15mm thick resin block, printed and cured by a 3D printer, was sputtered using an ion sputtering apparatus. The silver target in the ion sputtering apparatus was 50mm in diameter and 99.99% pure. During sputtering, the operating current of the ion sputtering apparatus was 20mA, the operating pressure was 4Pa, and the operating time was 1000 seconds. The shape of the silver selenide film was controlled by a 3D-printed mask, resulting in three elongated films, each 2mm x 15mm. After synthesizing the silver nanofilm, it was reacted with a pre-prepared sodium sulfide-selenium solution for 30 seconds. The solution was prepared by dissolving 0.6g of sodium sulfide nonahydrate in 20ml of double-distilled water. After complete dissolution, 0.2g of selenium powder was added, and the solution was stirred until it changed from colorless to deep red. After 30 seconds, the silver nanofilm changed from white to a grayish-blue silver selenide nanofilm. It was then rinsed with double-distilled water, cleaned, and dried at room temperature. The silver selenide film was then obtained. 1.2 Fabrication of Silver Selenide Biosensor

[0038] A silver selenide biosensor is constructed by connecting a silver selenide film end-to-end using conductive silver paste, then connecting it to wires to form a circuit. A polyethylene film is then placed over the film for protection. Finally, a 3D-printed resin block with circular holes is placed over the film; the area containing the holes serves as the sensing region. In this design, the silver selenide layer acts as the sensing layer, converting temperature differences into readable signals. The polyethylene film covering the silver selenide film provides protection and isolation, effectively preventing interference from external factors such as humidity, gases, and mechanical forces.

[0039] A schematic diagram of the synthesis of silver selenide thin films and the construction process of silver selenide biosensors is shown below. Figure 2 As shown in a.

[0040] 2. Sensor performance testing

[0041] The visible-ultraviolet absorption spectra of ABTS / HRP after incubation with different concentrations of hydrogen peroxide are as follows: Figure 3 As shown in bc. To confirm the specificity of this detection strategy, we compared the sensor's response to H2O2 and other common substances (including alcohol, glycine, glycerol, sodium chloride, and uric acid). Figure 3 d). The results show that the sensor exhibits a specific response only to H2O2. Therefore, this sensor has high sensitivity and specificity to H2O2. Figure 3As shown in Figure e, the sensor exhibits different voltage response curves for different hydrogen peroxide concentrations, indicating that higher concentrations elicit a stronger voltage response. Further analysis of the voltage difference ΔV at 60 seconds revealed a direct correlation between the voltage difference and the hydrogen peroxide concentration within a specific range, with an accuracy as high as 77.6 μV / μM. Furthermore, based on the formula 3σ / S (where σ represents the standard deviation of the blank sample and S represents the slope of the calibration curve), the detection limit was calculated to be 260 nM.

[0042] Example 3: Detection function of the silver selenide biosensor of the present invention for Streptococcus sanguinis.

[0043] Figure 4 A demonstrates the operational steps and basic principles for measuring the concentration of Streptococcus sanguinis using a thermoelectric effect-based sensor. First, hydrogen peroxide secreted by Streptococcus sanguinis reacts with a standard solution to generate ABTS·+. Subsequently, under 808nm laser excitation, ABTS·+ releases heat, causing a temperature difference in the sensor and generating a voltage signal, thereby enabling the detection of the Streptococcus sanguinis concentration.

[0044] Figure 4 Images b and 4c, imaged using microscopy and scanning electron microscopy respectively, confirmed the classic morphology of Streptococcus sanguinis and its uncontaminated state. The scanning electron microscopy images revealed the typical chain-like arrangement of Streptococcus sanguinis.

[0045] Figure 4 d shows different concentrations of Streptococcus sanguinis (ranging from 2 to 10 × 10⁻⁶). 5 The colony growth was observed after two days of incubation on BHI agar at a concentration of CFU / ml. The results showed that the number of colonies increased with increasing concentrations of Streptococcus sanguinis, indicating a direct correlation between colony count and bacterial concentration.

[0046] To investigate the relationship between the generated hydrogen peroxide and the concentration of Streptococcus sanguinis and Streptococcus sanguinis. Figure 5 e shows the results of staining with a ROS kit after incubation of bacteria at different concentrations in an anaerobic environment. Figure 4 The heatmap shows that the higher the bacterial concentration, the stronger the total fluorescence intensity. Figure 5 g further shows that the average fluorescence intensity per unit area increases linearly with increasing bacterial concentration.

[0047] Figure 4 h illustrates the use of the biosensor of the present invention to test the hydrogen peroxide concentration in the supernatant after centrifugation, and the results show that the hydrogen peroxide concentration is linearly related to the concentration of Streptococcus sanguinis. Figure 4The consistency of the above results was verified using a hydrogen peroxide reagent kit, further confirming the reliability of the sensor. Based on these results, the detection limit of this sensor for Streptococcus sanguinis was determined to be 3 × 10⁻⁶. 4 CFU / ml.

[0048] In summary, the thermoelectric effect-based sensor provided by this invention has the advantages of high sensitivity, strong specificity, and simple operation. It can accurately detect the hydrogen peroxide level and the concentration of Streptococcus sanguinis in beverages, which is of great significance for the prevention and treatment of oral diseases and heart infections.

[0049] Example 3: Detection function of the silver selenide biosensor of the present invention against methicillin-resistant Staphylococcus aureus (MRSA).

[0050] Figure 5 This study demonstrates the catalytic enzyme activity of MRSA in the presence of hydrogen peroxide and its impact on the thermoelectric sensor signal. MRSA can secrete catalase to resist damage from hydrogen peroxide. When MRSA was exposed to different concentrations of hydrogen peroxide and incubated, the supernatant obtained by centrifugation reacted with a standard solution. The presence of bacteria reduced the generation of ABTS·+, thereby weakening the electrical signal generated by the sensor and decreasing the temperature gradient. By comparing the weakened electrical signal with the original hydrogen peroxide signal, the concentration of MRSA can be determined.

[0051] Figure 5 Figure b shows the growth of different concentrations of MRSA on LB agar medium. After one day of incubation, the number of colonies on the agar was positively correlated with the MRSA concentration.

[0052] Figure 5 c shows the microstructure of MRSA at different concentrations after incubation with the same concentration (10 μM) of hydrogen peroxide. The results show that the damage caused by hydrogen peroxide to the bacteria decreases with increasing bacterial concentration, indicating that the catalase secreted by MRSA has a protective effect.

[0053] Figure 5 Figure d shows the ROS staining results of MRSA samples, with the lowest concentration of MRSA exhibiting the highest ROS intensity. Figure 5 The three-dimensional fluorescence intensity plot of e more intuitively shows the trend of ROS intensity decreasing with increasing MRSA concentration. Figure 5 Quantitative analysis of f further confirmed this pattern, indicating that the higher the bacterial concentration, the greater the consumption of hydrogen peroxide.

[0054] Figure 5g shows the results of detecting MRSA centrifuged supernatant after incubation with hydrogen peroxide using a biosensor. The voltage signal decreases with increasing bacterial concentration, indicating that MRSA decomposes the hydrogen peroxide. The linear relationship between the voltage signal and bacterial concentration demonstrates the potential of the sensor in MRSA detection. Figure 5 h shows the results of testing the same supernatant using a commercial hydrogen peroxide detection kit, with a consistent trend, further enhancing the reliability of the sensor.

[0055] In summary, the thermoelectric effect-based biosensor provided by this invention can detect MRSA concentration with high sensitivity, and the detection threshold is as low as 6 × 10⁻⁶. 4 The CFU / ml concentration exceeds the microbial concentration required for clinical infection diagnosis. This sensor has significant application value in MRSA detection and the diagnosis of drug-resistant infections.

Claims

1. A biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material and preparation thereof, characterized in that, The steps include: S1: First, use a 3D printer to print a resin block as a base; S2: Nano silver was sputtered onto a resin substrate in an ion sputtering instrument, and then synthesized into silver selenide by selenization reaction with sodium sulfide-selenium solution. S2: After the silver selenide film is prepared, silver paste is then attached to both ends of the silver selenide, one end being the sensing end and the other end being the control end; S3: Finally, a polyethylene film is placed over the film for protection; Its structure includes a sensing layer (1), which comprises a silver selenide film (11) and reference silver electrodes (12) and sensing silver electrodes (13) at both ends to form a sensing layer; and the region where the sensing layer is synthesized forms a base layer (2) on the resin and a polyethylene film covering the sensing layer forms a protective layer (3).

2. The biosensor based on silver selenide thermoelectric material for detecting hydrogen peroxide and / or bacteria according to claim 1, characterized in that, The silver selenide film (11) in the sensing layer (1) has a thickness of 100 nm and a length and width of 20 mm * 10 mm. The reference silver electrode (12) has a length and width of 10 mm * 3 mm. The sensing electrode (13) has a thickness of 100 nm and a length and width of 20 mm * 10 mm.

3. The biosensor based on silver selenide thermoelectric material for detecting hydrogen peroxide and / or bacteria according to claim 1, characterized in that, Its base layer (2) is resin, with a thickness of 15mm and a length and width of 25mm*10mm.

4. The biosensor based on silver selenide thermoelectric material for detecting hydrogen peroxide and / or bacteria according to claim 1, characterized in that, Its protective layer (3) is a polyethylene film with a thickness of 100μm and a length and width of 25mm*10mm.

5. A bio-sensing method based on thermoelectric nanogenerator, characterized in that, A biosensor for detecting hydrogen peroxide and / or bacteria based on silver selenide thermoelectric material as described in any one of claims 1-4, and its preparation thereof, wherein the method includes the following step of collecting the electrical signal generated when the heat generated by the reaction solution under 808nm laser excitation causes a temperature difference across the two ends of the sensor; The electrical signal is processed to obtain an electrical signal that meets preset conditions, and the hydrogen peroxide concentration signal, streptococcus concentration signal, and methicillin-resistant Staphylococcus aureus concentration signal are generated.

Images