Water algae detection device based on GaN chip and detection method for water algae

Abstract

The invention discloses a water algae detection device based on a GaN chip and a detection method for water algae thereof.The device is formed by integrating a microcystin sensor, a chlorophyll sensor and an ammonium ion sensor which share a substrate layer and a cover plate, and the structure of each unit sequentially comprises a gallium nitride layer, an aluminum gallium nitrogen barrier layer and a gallium nitride cap layer from bottom to top; a source electrode, a drain electrode and a grid electrode region are arranged on the gallium nitride cap layer in parallel, a sensing film with a microcystin and chlorophyll a combination function and an organic molecular polymer serving as an ammonium ion sensing film are deposited on the surface of the grid electrode region of each unit, and the aluminum gallium nitrogen barrier layer and the gallium nitride layer in the sensor form a heterojunction. Two-dimensional electron gas is formed in the channel and is sensitive to potential change of the surface of the grid electrode, and compared with a traditional water algae detection means, the method is more portable, detection is rapid, and the result is accurate.

Description

Technical Field

[0001] This invention belongs to the technical field of water body detection devices, specifically relating to a GaN chip-based water body algae detection device and its method for detecting water body algae. Background Technology

[0002] Cyanobacteria are ancient, large, single-celled prokaryotes widely distributed throughout the world, primarily concentrated in freshwater, accounting for about three-quarters of the total. Cyanobacteria contain chlorophyll but lack chloroplasts, enabling them to perform photosynthesis and release oxygen. Some species, such as *Anabaena*, contain nitrogenase and can directly fix nitrogen biologically. In eutrophic freshwater bodies polluted by nitrogen and phosphorus, cyanobacteria proliferate rapidly, forming a foul-smelling, blue-green scum on the surface, known as an algal bloom. Large-scale cyanobacterial blooms are called green tides. Cyanobacterial blooms cause water quality deterioration; the green algal layer on the surface depletes oxygen in the water while preventing oxygen from dissolving into the air, leading to fish mortality. Furthermore, species such as *Microcystis*, *Arthropoda*, and *Anabaena* can produce various toxins, posing a significant threat to the health of aquatic animals and humans.

[0003] Currently, eutrophication in freshwater lakes leads to frequent algal blooms, and cyanobacterial outbreaks also occur in areas with poor water flow, such as fishponds and artificial lakes in residential areas. Existing water monitoring primarily utilizes remote sensing technology, measuring and analyzing the spectral characteristics of water bodies within a specific wavelength range to obtain information such as chlorophyll concentration, suspended particulate matter content, and water transparency. However, satellite remote sensing is too costly for monitoring small bodies of water, and the results are significantly affected by environmental factors, making it unsuitable for precise water monitoring. Furthermore, the construction of satellite remote sensing monitoring systems is expensive. Therefore, a portable device capable of accurately detecting cyanobacterial blooms in water bodies is needed. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a GaN chip-based device for detecting algae in water.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: The device is composed of a microcystin sensor unit 100, a chlorophyll sensor unit 200, and an ammonium ion sensor unit 300 integrated on a single chip. Each unit shares a substrate layer 1 and a cover plate 2. A microfluidic channel (3) is connected between the gate detection areas of each sensing unit. The microcystin sensor unit 100 includes, from bottom to top, a first gallium nitride layer 101, a first aluminum gallium nitride barrier layer 102, and a first gallium nitride cap layer 103. A first sensor source 104, a first sensor drain 105, and a first gate region 106 are arranged side by side on the first gallium nitride cap layer 103. A sensing film with microcystin binding function is deposited on the surface of the first gate region 106. The chlorophyll sensor unit 200 includes, from bottom to top, a second gallium nitride layer 201, a second aluminum gallium nitride barrier layer 202, and a second gallium nitride cap layer 203. A second sensor source 204, a second sensor drain 205, and a second gate region 206 are arranged side by side on the second gallium nitride cap layer 203. A sensing film with chlorophyll a binding function is deposited on the surface of the second gate region 206. The ammonium ion sensor unit 300 includes, from bottom to top, a third gallium nitride layer 301, a third aluminum gallium nitride barrier layer 302, and a third gallium nitride cap layer 303. A second sensor source 304, a third sensor drain 305, and a third gate region 306 are arranged side by side on the third gallium nitride cap layer 303. An organic molecular polymer, which serves as an ammonium ion sensing film, is deposited on the surface of the third gate region 306.

[0008] As a preferred embodiment of the GaN chip-based aquatic algae detection device of the present invention, the substrate layer 1 has a thickness of 20,000~30,000 nm and the material includes one of silicon, silicon carbide, and sapphire. The first gallium nitride layer 101, the second gallium nitride layer 201, and the third gallium nitride layer 301 have the same thickness, which is 100~1000nm. The first aluminum gallium nitride barrier layer 102, the second aluminum gallium nitride barrier layer 202, and the third aluminum gallium nitride barrier layer 302 have the same thickness, which is 10~100nm. The first gallium nitride cap layer 103, the second gallium nitride cap layer 203, and the third gallium nitride cap layer 303 have the same thickness, which is 1~50nm.

[0009] As a preferred embodiment of the GaN chip-based aquatic algae detection device of the present invention, wherein: the first sensor source 104, the second sensor source 204, and the third sensor source 304; the first sensor drain 105, the second sensor drain 205, and the third sensor drain 305 are all made of Ti / Al / Ni / Au stacked structure, with each layer having a thickness of 20nm, 100nm, 70nm, and 70nm, respectively.

[0010] As a preferred embodiment of the GaN chip-based aquatic algae detection device of the present invention, the thickness of the sensing membrane with microcystin binding function is 100~400nm, the thickness of the sensing membrane with chlorophyll a binding function is 100~400nm, and the thickness of the ammonium ion sensing membrane is 20~200nm.

[0011] As a preferred embodiment of the GaN chip-based aquatic algae detection device of the present invention, the sensing membrane with microcystin binding function is obtained by mixing microcystin antibody and gold nanoparticles.

[0012] As a preferred embodiment of the GaN chip-based aquatic algae detection device of the present invention, wherein: the specific receptor of the sensing membrane with chlorophyll a binding function is Lhcb1, and the sensing membrane carrier is polyvinyl chloride.

[0013] As a preferred embodiment of the GaN chip-based aquatic algae detection device of the present invention, the ammonium ion sensing membrane is made of polyvinyl chloride as the sensing membrane carrier, dioctyl phthalate as the plasticizer, valine as the ammonium ion sensitive substance, and tetrahydrofuran as the solvent.

[0014] Another objective of this invention is to provide a method for detecting aquatic algae using a GaN chip-based aquatic algae detection device.

[0015] To solve the above-mentioned technical problems, the present invention provides the following technical solutions, including: The source and drain voltages of the microcystin sensor, chlorophyll a sensor, and ammonium ion sensor were set according to their parameters, with the source voltage being 1V and the drain voltage being 0V. Prepare standard buffer solutions with different concentrations of microcystin, chlorophyll a, and ammonium ion, respectively, and introduce them into the microfluidic channel of the detection device. Measure the output current when the device is stable to obtain the standard curves of microcystin, chlorophyll a, and ammonium ion of the device. The ultrasonically broken test solution is fed into the microfluidic channel of the detection device. After the three output currents stabilize, their values ​​are compared with the standard curves for microcystin, chlorophyll a, and ammonium ions, respectively. The concentrations of microcystin, chlorophyll a, and ammonium ions in the test solution are determined based on the magnitude of the output current of the test solution and the standard curves, so as to determine whether there is a risk of algal bloom in the source water body of the test solution.

[0016] As a preferred embodiment of the method for detecting aquatic algae using the GaN chip-based aquatic algae detection device of the present invention, wherein: the microcystin standard buffer is a mixture of PBS solution and physiological saline, the chlorophyll a standard buffer is a mixture of PBS solution and physiological saline, and the ammonium ion standard buffer is a mixture of PBS solution and physiological saline.

[0017] As a preferred embodiment of the method for detecting aquatic algae using the GaN chip-based aquatic algae detection device of the present invention, the test solution is a mixture of source water sample, PBS solution and physiological saline, with the ratio of each component being 1:1:1.

[0018] Beneficial effects of this invention: In the sensor structure of this invention, the aluminum gallium nitride barrier layer and gallium nitride layer form a heterojunction. Due to the piezoelectric and polarization effects, a two-dimensional electron gas is formed in the channel, which is sensitive to potential changes on the gate surface. Algal toxins bind to specific receptors on their sensing membranes, causing changes in their potential. Chlorophyll a carries a negative charge in neutral to alkaline solutions and can bind to specific receptors on its sensing membranes, causing changes in membrane potential. The ammonium ion sensing membrane changes its potential after binding with ammonium ions. Compared with traditional methods for detecting algae in water, this method is more portable, faster, and more accurate. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a front view of a GaN chip-based aquatic algae detection device.

[0020] Figure 2 This is a top view of a GaN chip-based aquatic algae detection device.

[0021] Figure 3 This is a comparison chart showing the results of detecting microcystin concentration using the water algae detection devices prepared in Example 1 and Comparative Example 1.

[0022] Figure 4 This is a comparison chart showing the results of detecting chlorophyll a concentration using the aquatic algae detection devices prepared in Example 1 and Comparative Example 1.

[0023] Figure 5 This is a comparison chart showing the results of ammonium ion concentration detection by the water algae detection devices prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0027] Unless otherwise specified, all raw materials used in this invention are commercially available in the art. Specifically, the parameters and models of the raw materials are as follows: Lhcb1: Amyjet Scientific, AS01-00; Microcystin (MC-LR): meilunbio, MB2143; MC-LR antibody: Boiling Snow gene, PHY-AB-DS12; Valinomycin: MCE, HY-N6693; Example 1 Reference Figure 1 , Figure 2 This embodiment provides a water algae detection device based on a GaN chip. Figure 1 This is a front view of a GaN chip-based water algae detection device. Figure 2 This is a top view of a GaN chip-based aquatic algae detection device. The arrows in the figure indicate the flow direction of the liquid being tested.

[0028] like Figure 1As shown, the water algae detection device based on GaN chip is composed of a microcystin sensor unit 100, a chlorophyll sensor unit 200 and an ammonium ion sensor unit 300 integrated on a single chip. Each unit shares a substrate layer 1 and a cover plate 2. Microfluidic channels 3 are connected between each unit. The substrate layer material is sapphire with a thickness of 30,000 nm. The microcystin sensor unit 100 includes, from bottom to top, a first gallium nitride layer 101, a first aluminum gallium nitride barrier layer 102, and a first gallium nitride cap layer 103. A first sensor source 104, a first sensor drain 105, and a first gate region 106 are arranged side by side on the first gallium nitride cap layer 103. A sensing film with microcystin binding function is deposited on the surface of the first gate region 106. The chlorophyll sensor unit 200 includes, from bottom to top, a second gallium nitride layer 201, a second aluminum gallium nitride barrier layer 202, and a second gallium nitride cap layer 203. A second sensor source 204, a second sensor drain 205, and a second gate region 206 are arranged side by side on the second gallium nitride cap layer 203. A sensing film with chlorophyll a binding function is deposited on the surface of the second gate region 206. The ammonium ion sensor unit 300 includes, from bottom to top, a third gallium nitride layer 301, a third aluminum gallium nitride barrier layer 302, and a third gallium nitride cap layer 303. A second sensor source 304, a third sensor drain 305, and a third gate region 306 are arranged side by side on the third gallium nitride cap layer 303. An organic molecular polymer, which serves as an ammonium ion sensing film, is deposited on the surface of the third gate region 306.

[0029] The thickness of the gallium nitride layer in each unit is 300 nm; the thickness of the aluminum gallium nitride barrier layer is 25 nm; the thickness of the gallium nitride cap layer is 5 nm; the source and drain materials are both Ti / Al / Ni / Au stacked structures with thicknesses of 20 nm, 100 nm, 70 nm, and 70 nm, respectively; the thickness of the microcystin sensing film is 150 nm; the thickness of the chlorophyll a sensing film is 200 nm; and the thickness of the ammonium ion sensing film is 50 nm.

[0030] The fabrication method of the water algae detection device based on GaN chip is as follows: 1) Gallium nitride and aluminum gallium nitride layers of each unit are grown on a sapphire substrate by MOCVD to form a channel structure, and a gallium nitride cap layer is deposited on top of the channel structure. 2) After the active region is isolated, the source and drain electrodes of each unit are formed by vapor deposition process, which is a Ti / Al / Ni / Au stacked structure. 3) The microcystin sensing membrane of the deposited microcystin sensor unit has microcystin antibodies as its specific receptors and gold nanoparticles (AuNPs) as its carriers: Gold nanoparticles were grown above the gate region of the microcystin sensor unit by electrochemical deposition. After immersing the gate region of the sensor with deposited gold nanoparticles in a 0.5 mM aqueous solution of microcystin antibody for 30 h, the gate surface was dried with nitrogen and left to stand at room temperature until the moisture completely evaporated, forming a sensing film with microcystin binding function and a thickness of 150 nm.

[0031] 4) The chlorophyll a sensing membrane of the deposited chlorophyll sensor unit has Lhcb1 as its specific receptor, and the sensing membrane carrier is polyvinyl chloride (PVC): Dissolve 25 mg of a mixture of Lhcb1, polyvinyl chloride, and dioctyl phthalate in a ratio of 1:7:17 in 250 ml of anhydrous tetrahydrofuran until fully dissolved to form a homogeneous solution. Use a micropipette to take an appropriate amount of solution and drop it onto the gate region of the chlorophyll sensor unit; When left to stand at room temperature until the tetrahydrofuran completely evaporates, a solid film is formed, which is the chlorophyll a sensing film with a thickness of 200 nm. 5) The ammonium ion sensing membrane of the deposited ammonium ion sensor unit uses polyvinyl chloride as the sensing membrane carrier and valacyclovir as the ammonium ion sensitive substance: A mixture of 50 mg of valproic acid, polyvinyl chloride, and dioctyl phthalate in a ratio of 1:14:35 was dissolved in 500 ml of anhydrous tetrahydrofuran and allowed to dissolve completely to form a homogeneous solution. Use a micropipette to take an appropriate amount of solution and add it dropwise to the grid region of the ammonium ion sensor; When left to stand at room temperature until the tetrahydrofuran completely evaporates, a solid film is formed, which is the ammonium ion sensing film with a thickness of 50 nm. Among them, gallium nitride has high adhesion to polyvinyl chloride film, requiring no additional chemical bonding; 6) Embed the entire device into a PMMA board of the corresponding size, and obtain microfluidic channels flowing through the detection areas of the three sensor gates by coating, exposure and development. Finally, encapsulate the device, leaving liquid channels and electrode channels to obtain the final device.

[0032] Example 2 This embodiment is used to verify the effectiveness of the GaN chip-based aquatic algae detection device obtained in Example 1 in detecting aquatic algae. Specifically: S1: Set the source and drain voltages of the microcystin sensor, chlorophyll a sensor, and ammonium ion sensor respectively according to their parameters. In this embodiment, the source of the sensor is grounded and the drain voltage is set to 5V. S2: Determine the microcystin standard curve for this device; A buffer solution was prepared by mixing 20 ml of physiological saline and 20 ml of PBS solution. The buffer solution containing different concentrations of microcystin (1E-8, 1E-7, 1E-6, 1E-5, 1E-4 g / L) was passed into the sensing device, and the output current under this condition was measured to determine the microcystin standard curve of the device.

[0033] S3: Determine the standard curve for chlorophyll a value of this device; A buffer solution was prepared by mixing 20 ml of physiological saline and 20 ml of PBS solution. Different chlorophyll a concentrations of 1E-8, 1E-7, 1E-6, 1E-5, and 1E-4 g / L were introduced into the sensing device, and the output current under these conditions was measured to determine the chlorophyll a standard curve of the device.

[0034] S4: Determine the ammonium ion standard curve for this device; A buffer solution was prepared by mixing 20 ml of physiological saline and 20 ml of PBS solution. Buffer solutions with different ammonium chloride concentrations of 1E-5, 1E-4, 1E-3, 0.01, and 0.1 mol / L were passed into the sensing device, and the output current under these conditions was measured, thus determining the ammonium ion standard curve of the device.

[0035] S5: Detection of algae samples from water bodies; The water sample to be tested is fed into the microfluidic channel of the detection device. After the three output currents stabilize, their values ​​are compared with the standard curves for microcystin, chlorophyll a, and ammonium ions, respectively. The concentrations of microcystin, chlorophyll a, and ammonium ions in the test solution are determined based on the magnitude of the output current of the test solution and the standard curves, so as to determine whether there is a risk of algal bloom in the source water body of the test solution.

[0036] Comparative Example 1 This embodiment provides another water algae detection device based on GaN chip. Unlike embodiment 1, the thickness of the AlGaN barrier layer of the sensor is 80nm. The other structural materials of this device are the same as those in embodiment 1.

[0037] Reference Figure 3 The results of detecting microcystin concentration using the devices prepared in Example 1 and Comparative Example 1 are shown in the figure. It can be seen from the figure that different current values ​​correspond to different microcystin concentrations. As the concentration of microcystin in the measured water sample solution increases, the output current decreases.

[0038] Reference Figure 4 The figure shows the results of the device obtained in Example 1 and Comparative Example 1 in detecting the concentration of chlorophyll a. It can be seen from the figure that different current values ​​correspond to different chlorophyll a concentrations. As the concentration of chlorophyll a in the water sample solution increases, the output current decreases.

[0039] Reference Figure 5 The results of the detection of ammonium ion concentration by the devices prepared in Example 1 and Comparative Example 1 are shown in the figure. It can be seen from the figure that the output current increases with the increase of the ammonium ion concentration in the measured solution.

[0040] Reference Figures 3-5 As can be seen, Example 1, with its higher AlGaN barrier height, exhibits a larger overall on-current response value, and the change in on-current corresponding to the same concentration change is greater, indicating higher sensitivity. This is because the conductive channel formed by the AlGaN / GaN heterostructure is located on the GaN surface at the interface. The greater the thickness of the AlGaN barrier layer, the weaker the gate's ability to control the two-dimensional electron gas in the channel, resulting in a decrease in the device's on-current and a reduction in device sensitivity.

[0041] In summary, the aluminum gallium nitride barrier layer and gallium nitride layer in the sensor structure of the GaN chip-based aquatic algae detection device of this invention form a heterojunction. Due to the piezoelectric and polarization effects, a two-dimensional electron gas is formed in the channel, which is sensitive to potential changes on the gate surface. Algal toxins bind to specific receptors on their sensing membranes, causing changes in their potential. Chlorophyll a carries a negative charge in neutral to alkaline solutions and can bind to specific receptors on its sensing membranes, causing changes in membrane potential. The ammonium ion sensing membrane changes its potential after binding with ammonium ions. Compared with traditional aquatic algae detection methods, this device is more portable, faster, and provides more accurate results.

[0042] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A GaN chip-based device for detecting algae in water, characterized in that: The device integrates a microcystin sensor unit (100), a chlorophyll sensor unit (200), and an ammonium ion sensor unit (300) onto a single chip. Each unit shares a substrate layer (1) and a cover plate (2). Microfluidic channels (3) connect the gate detection regions of each sensing unit. The microcystin sensor unit (100) comprises, from bottom to top, a first gallium nitride layer (101), a first aluminum gallium nitride barrier layer (102), and a first gallium nitride cap layer (103). A first sensor source (104), a first sensor drain (105), and a first gate region (106) are arranged side by side on the first gallium nitride cap layer (103). A sensing film with microcystin binding function is deposited on the surface of the first gate region (106). The chlorophyll sensor unit (200) includes, from bottom to top, a second gallium nitride layer (201), a second aluminum gallium nitride barrier layer (202), and a second gallium nitride cap layer (203). A second sensor source (204), a second sensor drain (205), and a second gate region (206) are arranged side by side on the second gallium nitride cap layer (203). A sensing film with chlorophyll a binding function is deposited on the surface of the second gate region (206). The structure of the ammonium ion sensor unit (300) from bottom to top includes a third gallium nitride layer (301), a third aluminum gallium nitride barrier layer (302), and a third gallium nitride cap layer (303). A second sensor source (304), a third sensor drain (305), and a third gate region (306) are arranged side by side on the third gallium nitride cap layer (303). An organic molecular polymer, which serves as an ammonium ion sensing film, is deposited on the surface of the third gate region (306).

2. The GaN chip-based aquatic algae detection device as described in claim 1, characterized in that: The substrate layer (1) has a thickness of 20,000~30,000 nm and is made of one of silicon, silicon carbide, or sapphire. The first gallium nitride layer (101), the second gallium nitride layer (201), and the third gallium nitride layer (301) have the same thickness, which is 100~1000nm; The first aluminum gallium nitride barrier layer (102), the second aluminum gallium nitride barrier layer (202), and the third aluminum gallium nitride barrier layer (302) have the same thickness, which is 10~100nm. The first gallium nitride cap layer (103), the second gallium nitride cap layer (203), and the third gallium nitride cap layer (303) have the same thickness, which is 1~50nm.

3. The GaN chip-based aquatic algae detection device as described in claim 1, characterized in that: The first sensor source (104), the second sensor source (204), and the third sensor source (304) are all made of Ti / Al / Ni / Au stacked structure, with each layer having a thickness of 20nm, 100nm, 70nm, and 70nm, respectively.

4. The GaN chip-based aquatic algae detection device as described in claim 1, characterized in that: The thickness of the sensing membrane with microcystin binding function is 100~400nm, the thickness of the sensing membrane with chlorophyll a binding function is 100~400nm, and the thickness of the ammonium ion sensing membrane is 20~200nm.

5. The GaN chip-based aquatic algae detection device as described in claim 4, characterized in that: The sensing membrane with microcystin binding function is obtained by mixing microcystin antibody with gold nanoparticles.

6. The GaN chip-based aquatic algae detection device as described in claim 4, characterized in that: The specific receptor for the sensing membrane with chlorophyll a binding function is Lhcb1, and the sensing membrane carrier is polyvinyl chloride.

7. The GaN chip-based aquatic algae detection device as described in claim 4, characterized in that: The ammonium ion sensing membrane is made of polyvinyl chloride as the sensing membrane carrier, dioctyl phthalate as the plasticizer, valine as the ammonium ion sensitive substance, and tetrahydrofuran as the solvent.

8. The method for detecting aquatic algae using the GaN chip-based aquatic algae detection device as described in any one of claims 1 to 7, characterized in that: include, The source and drain voltages of the microcystin sensor, chlorophyll a sensor, and ammonium ion sensor were set according to their parameters, with the source voltage being 1V and the drain voltage being 0V. Prepare standard buffer solutions with different concentrations of microcystin, chlorophyll a, and ammonium ion, respectively, and introduce them into the microfluidic channel of the detection device. Measure the output current when the device is stable to obtain the standard curves of microcystin, chlorophyll a, and ammonium ion of the device. The ultrasonically broken test solution is fed into the microfluidic channel of the detection device. After the three output currents stabilize, their values ​​are compared with the standard curves for microcystin, chlorophyll a, and ammonium ions, respectively. The concentrations of microcystin, chlorophyll a, and ammonium ions in the test solution are determined based on the magnitude of the output current of the test solution and the standard curves, so as to determine whether there is a risk of algal bloom in the source water body of the test solution.

9. The method for detecting aquatic algae using the GaN chip-based aquatic algae detection device as described in claim 8, characterized in that: The microcystin standard buffer solution is a mixture of PBS solution and physiological saline, the chlorophyll a standard buffer solution is a mixture of PBS solution and physiological saline, and the ammonium ion standard buffer solution is a mixture of PBS solution and physiological saline.

10. The method for detecting aquatic algae using the GaN chip-based aquatic algae detection device as described in claim 8, characterized in that: The test solution is a mixture of source water sample, PBS solution and physiological saline, with each component in a ratio of 1:1:1.

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