An in-situ detection chip for multi-parameters of marine ecology

Abstract

The present invention relates to the field of integrated circuit technology, and discloses a multi-parameter in-situ detection chip for marine ecology. It includes a heavy metal detection chip module, and the heavy metal detection chip module successively includes a chromium layer, a gold layer and a titanium layer from top to bottom; wherein the thickness of the chromium layer is 5-10 nm, the thickness of the gold layer is 50-60 nm, and the thickness of the titanium layer is 5-10 nm. This chip realizes the detection of heavy metal ions in seawater with a smaller area, and sensitive on-chip devices can further lower the detection limit, thereby improving the dynamic sensitivity of the detection. Compared with existing detection devices, the detection chip has higher integration, stability and sensitivity, and the detection ability is significantly improved; the heavy metal detection module can also be integrated with the pH and temperature detection modules to achieve multi-parameter detection functions; a sensitive layer is also provided on the heavy metal detection chip module to improve the sensitivity of the detection; a gel protective film is also provided on the heavy metal detection chip module to protect the electrodes and improve their reusability.

Description

Technical Field

[0001] The present invention belongs to the field of integrated circuits, and particularly relates to a multi-parameter in-situ detection chip for marine ecology. Background Art

[0002] Heavy metal ions refer to the ionic forms of metal elements with relatively high atomic masses, such as mercury, lead, cadmium, chromium, etc. The main sources of heavy metal ions in the marine ecosystem include industrial wastewater, pesticides, mine discharges, and ship wastewater. Heavy metal ions have various harms to the marine ecosystem. They are highly toxic and can directly poison marine organisms. They can accumulate in organisms, affecting their growth, development, reproductive ability, immune system and other functions, and even causing chronic toxicity and death. Coral reefs, mangroves, and seagrass beds are the three most concerned marine ecosystems. As one of the ecosystems with the highest primary productivity globally, nearly a quarter of marine species rely on coral reefs for reproduction and survival. Studies have shown that heavy metals such as zinc, cadmium, lead, and copper in seawater at certain concentrations will significantly reduce the fertilization success rate of coral gametes.

[0003] In summary, there is currently a need for a multi-parameter detection device that can in-situ detect the parameters of heavy metal ions in seawater and other parameters of seawater. Summary of the Invention

[0004] To solve the technical problems raised in the above background art, the present invention provides a multi-parameter in-situ detection chip for marine ecology. This chip realizes the detection of heavy metal ions in seawater with a smaller area, and the sensitive on-chip devices can further lower the detection limit, thereby improving the dynamic sensitivity of the detection.

[0005] The present invention is implemented by the following technical solutions: A multi-parameter in-situ detection chip for marine ecology, including a heavy metal detection chip module. The heavy metal detection chip module includes a chromium layer, a gold layer, and a titanium layer from top to bottom in sequence; wherein the thickness of the chromium layer is 5 - 10 nm, the thickness of the gold layer is 50 - 60 nm, and the thickness of the titanium layer is 5 - 10 nm.

[0006] Among them, using a chip containing gold elements to detect heavy metal ions in seawater is based on the principle of electrochemistry. The chip is placed in the sea area to be detected, and the gold layer is immersed in the seawater sample to make it fully contact with the sample. Heavy metal ions can be allowed to adsorb and accumulate on the surface of the gold electrode within a certain period of time. Then, an electrochemistry analyzer, such as a potentiometer or an electrochemistry workstation, is used to test the gold electrode. Methods such as Cyclic Voltammetry or Square Wave Voltammetry can be used for testing. During the testing process, a series of potentials are applied to observe the current response. The adsorption and electrochemical reaction of heavy metal ions on the gold electrode will cause current changes. According to the magnitude and shape of the current changes, the concentration of heavy metal ions in seawater can be inferred. Finally, by comparing the measured current signal with a standard curve or a standard solution with a known concentration, the concentration of heavy metal ions in seawater can be determined. In addition, different heavy metal ions, such as lead and copper, may have different electrochemical behaviors and response characteristics. Therefore, in specific experiments, it is necessary to optimize and verify the method for the target heavy metal ions.

[0007] As a further improvement of the above solution, the heavy metal detection chip module further includes a SiO2 layer located above the chromium layer.

[0008] As a further improvement of the above solution, the heavy metal detection chip module further includes a number of gold electrode holes provided on the chromium layer and the SiO2 layer, and the diameter of the gold electrode holes is 5-6 μm.

[0009] Among them, by forming a silicon oxide layer on the surface of the gold electrode and etching holes, the specific surface area of the gold electrode in contact with seawater can be increased, that is, seawater can stay in the holes for a longer time. This can improve the adsorption amount of heavy metal ions on the surface of the gold electrode, thereby improving the detection sensitivity. The size and shape of the etched gold electrode holes can be controlled so that only the gold electrode part is exposed. This can improve the selectivity of the gold electrode for specific heavy metal ions and reduce the influence of other interfering substances. In addition, the interface formed between the gold electrode and the silicon oxide layer can provide a more stable electrochemical environment. This helps to reduce electrochemical noise and background signals and improve the accuracy and reliability of heavy metal ion detection. And the presence of the silicon oxide layer can enhance the interaction between heavy metal ions and the gold electrode, thereby enhancing the response of the electrochemical signal. This helps to improve the detection sensitivity and accuracy. In particular, if the surface of the gold electrode is contaminated or damaged, the gold electrode can be conveniently repaired and regenerated by re-preparing the silicon oxide layer and etching holes, and its service life can be extended. And the diameter of the gold electrode holes is limited to 5-6 μm. Such a small hole diameter can limit the diffusion of the solution in the holes, making heavy metal ions more concentrated in contact with the gold electrode, thereby increasing the detection sensitivity.

[0010] As a further improvement of the above solution, the distance between the centers of the gold electrode holes is 200 - 250 μm.

[0011] Among them, by setting multiple gold electrode holes and controlling their spacing, the effective contact area on the surface of the gold electrode can be increased, thereby increasing the adsorption amount of heavy metal ions. This can increase the sensitivity and accuracy of heavy metal ion detection. The spacing between two adjacent holes is 200 μm, which can improve the spatial resolution of heavy metal ion detection at the microscale. This helps to locate and distinguish the differences in heavy metal ion concentrations in different regions or microenvironments. In addition, setting the spacing between two adjacent holes can reduce the interference effect between adjacent holes. For example, when detecting a complex sample containing multiple heavy metal ions, the spacing between adjacent holes can reduce the interaction and cross-interference between each other, improving the selectivity and accuracy of detection.

[0012] As a further improvement of the above solution, the heavy metal detection chip module further includes a sensitive film disposed on the gold electrode holes.

[0013] As a further improvement of the above solution, the sensitive film includes one of mercury or bismuth.

[0014] Among them, mercury or bismuth as the sensitive film can enhance the interaction between heavy metal ions and the gold electrode, thereby increasing the intensity of the detection signal. This can improve the sensitivity of heavy metal ion detection, enabling the reliable detection of the presence of heavy metal ions even at low concentrations. And by selecting a suitable sensitive film material, the selectivity for specific heavy metal ions can be increased. For example, bismuth has high selectivity in heavy metal ion detection and can be used to detect lead ions, which helps to reduce the influence of other interfering substances and improve the accuracy and reliability of detection. In addition, mercury or bismuth as the sensitive film can achieve a faster response and recovery, enabling the heavy metal ion detection to be carried out more quickly.

[0015] As a further improvement of the above solution, the heavy metal detection chip module further includes a gel protective film disposed on the SiO2 layer and covering the sensitive film.

[0016] As a further improvement of the above solution, the gel protective film includes agar.

[0017] Among them, the gel protective film can prevent impurities in seawater from damaging the sensitive film, block larger-diameter particulate matters and organic matters, but allow heavy metal ions to pass through.

[0018] As a further improvement of the above solution, the detection area of the heavy metal detection chip module is 4000×2000 μm2.

[0019] The area of the above-mentioned heavy metal detection chip module is extremely small, with a maximum not exceeding 15 mm. 2 This enables it to be better set at any position where the seawater quality is to be detected, with basically no geographical restrictions. Moreover, the heavy metal detection chip module of this size is provided with a sufficient number of gold electrodes to meet the detection needs.

[0020] A preparation method for an in-situ multi-parameter detection chip for marine ecology as described in any one of the above, comprising the following steps:

[0021] S01. Take a silicon oxide wafer with a size of 4 - 6 inches and a thickness of 300 - 400 nm;

[0022] S02. Magnetron sputter the chromium layer, gold layer and titanium layer;

[0023] S03. Plasma enhanced chemical vapor deposition of the SiO2 layer;

[0024] S04. Reactively ion etch the SiO2 layer to obtain the gold electrode holes;

[0025] S05. Etch the chromium layer to obtain the gold electrode holes and expose part of the gold layer;

[0026] S06. Remove the photoresist and clean.

[0027] Among them, reactive ion etching is a method for precisely controlling the hole size and shape. By adjusting etching parameters such as ion beam energy, angle and time, etc., precise control of the hole diameter, depth and shape can be achieved. This enables the customization of the required hole size and morphology according to specific needs. Reactive ion etching has high processing precision and can fabricate holes at the sub-micron scale. This is very important for the fields of micro-nano processing and nanotechnology, such as applications in nanoelectronic devices and biosensors. And compared with traditional physical etching methods, reactive ion etching causes less surface contamination and damage to the substrate material. It can achieve relatively smooth and non-damaged hole walls, which is beneficial to improving the performance and stability of the device.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. Compared with the existing detection devices, the detection chip has higher integration, stability and sensitivity, and the detection ability is significantly improved;

[0030] 2. The heavy metal detection module can also be integrated with the pH and temperature detection modules to achieve the multi-parameter detection function;

[0031] 3. A sensitive layer is also provided on the heavy metal detection chip module to improve the detection sensitivity;

[0032] 4. A gel protective film is also provided on the heavy metal detection chip module to protect the electrodes and improve its reusability. Brief Description of the Drawings

[0033] Figure 1 It is a schematic structural diagram of the in-situ detection chip for multi-parameters of marine ecology.

[0034] Figure 2 It is a schematic structural diagram of the heavy metal detection chip module.

[0035] Figure 3 It is a schematic structural diagram of the heavy metal detection chip module with a sensitive film and a gel protective film.

[0036] Figure 4 It is a schematic structural diagram of the heavy metal detection chip from a top-down perspective.

[0037] Main Symbol Explanation:

[0038] Heavy metal detection chip module 1, temperature detection chip module 2, pH detection chip module 3, chromium layer 101, gold layer 102, titanium layer 103, SiO2 layer 104, gold electrode hole 105, sensitive film 106, gel protective film 107. Detailed Embodiments

[0039] Next, in combination with the drawings and specific embodiments, the present invention will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be combined arbitrarily to form new embodiments.

[0040] Embodiment 1:

[0041] In this embodiment, the in-situ detection chip for multi-parameters of marine ecology includes a heavy metal detection chip module 1. The heavy metal detection chip module 1 successively includes a chromium layer 101, a gold layer 102, and a titanium layer 103 from top to bottom. Among them, the thickness of the chromium layer 101 is 5 nm, the thickness of the gold layer 102 is 50 nm, and the thickness of the titanium layer 103 is 5 nm.

[0042] Furthermore, the heavy metal detection chip module 1 further includes a SiO2 layer 104 located above the chromium layer 101.

[0043] Furthermore, the heavy metal detection chip module 1 further includes a plurality of gold electrode holes 105 provided on the chromium layer 101 and the SiO2 layer 104. The diameter of the gold electrode hole 105 is 5 μm.

[0044] Furthermore, the distance between the centers of the gold electrode holes 105 is 200 μm.

[0045] Embodiment 2:

[0046] In this embodiment, the marine ecological multi-parameter in-situ detection chip includes a heavy metal detection chip module 1. The heavy metal detection chip module 1 successively includes a chromium layer 101, a gold layer 102, and a titanium layer 103 from top to bottom. Among them, the thickness of the chromium layer 101 is 10 nm, the thickness of the gold layer 102 is 60 nm, and the thickness of the titanium layer 103 is 10 nm.

[0047] Furthermore, the heavy metal detection chip module 1 further includes a SiO2 layer 104 located above the chromium layer 101.

[0048] Furthermore, the heavy metal detection chip module 1 further includes a number of gold electrode holes 105 provided on the chromium layer 101 and the SiO2 layer 104. The diameter of the gold electrode holes 105 is 6 μm.

[0049] Furthermore, the distance between the centers of the gold electrode holes 105 is 250 μm.

[0050] Embodiment Three:

[0051] In this embodiment, the marine ecological multi-parameter in-situ detection chip includes a heavy metal detection chip module 1. The heavy metal detection chip module 1 successively includes a chromium layer 101, a gold layer 102, and a titanium layer 103 from top to bottom. Among them, the thickness of the chromium layer 101 is 5 nm, the thickness of the gold layer 102 is 50 nm, and the thickness of the titanium layer 103 is 5 nm.

[0052] Furthermore, the heavy metal detection chip module 1 further includes a SiO2 layer 104 located above the chromium layer 101.

[0053] Furthermore, the heavy metal detection chip module 1 further includes a number of gold electrode holes 105 provided on the chromium layer 101 and the SiO2 layer 104. The diameter of the gold electrode holes 105 is 5 μm.

[0054] Furthermore, the distance between the centers of the gold electrode holes 105 is 200 μm.

[0055] Furthermore, the heavy metal detection chip module 1 further includes a sensitive film 106 provided on the gold electrode holes 105. The sensitive film 106 is mercury.

[0056] Embodiment Four:

[0057] In this embodiment, the difference from Embodiment Three is that the sensitive film 106 is bismuth.

[0058] Embodiment Five:

[0059] In this embodiment, it includes any one of the marine ecological multi-parameter in-situ detection chips in Embodiment 3 or Embodiment 4, and further includes: a gel protective film 107 disposed on the SiO2 layer 104 and covering the sensitive film 106, and the gel protective film 107 is agar.

[0060] The chips of Embodiment 1, 2, 3, 4, and 5 are tested, specifically including:

[0061] Sensitivity test: By contacting the chip with heavy metal ion solutions of different concentrations and measuring the changes in current or voltage signals to evaluate the sensitivity of the chip. A standard curve can be plotted based on the relationship between the signal intensity and the heavy metal ion concentration, and sensitivity indicators such as the detection limit and linear range can be calculated.

[0062] Selectivity test: By exposing the chip to a solution containing other interfering ions, the selectivity of the heavy metal ions is detected. By comparing the differences between the heavy metal ion signals and the interfering ion signals, the selectivity of the chip for the target heavy metal ions is evaluated.

[0063] Response time test: Measure the response time of the chip to heavy metal ions, that is, the time required from contacting the heavy metal ion solution to reaching a stable state. A shorter response time usually indicates a faster detection speed and dynamic response ability.

[0064] Stability test: Through long-term stability tests, evaluate the performance stability of the chip under different environmental conditions. This can include testing under different temperature and pH values and other conditions to ensure the long-term reliability and stability of the chip.

[0065] Repeatability and reproducibility test: Through multiple repeated experiments, evaluate the repeatability and reproducibility of the chip. This can be determined by calculating the degree of signal variation between different experiments.

[0066] Actual sample test: Finally, in order to evaluate the application performance of the chip in actual samples, real samples containing heavy metal ions can be used for testing. This can verify the accuracy and reliability of the chip in complex sample matrices.

[0067] The results show that the sensitivity, selectivity, response time, stability, and repeatability of the chips of Embodiment 1, 2, 3, 4, and 5 all meet the test standards, that is, they can meet the requirements for the detection of heavy metals in seawater.

[0068] In addition, the sensitivity of the chips of Embodiment 3 and 4 is better than that of Embodiment 1 and 2. This is because after adding the sensitive film 106, the sensitive film can enhance the interaction between heavy metal ions and the gold electrode, thereby increasing the intensity of the detection signal. And the selectivity of the chip of Embodiment 3 is slightly better than that of the chip of Embodiment 4, indicating that mercury as the sensitive film 106 can improve the selectivity of the chip.

[0069] Specifically, the repeatability of the chip in Example 5 is better than that of the chips in Examples 1, 2, 3, and 4. This is because the gel protective film 107 can prevent impurities in seawater from damaging the sensitive film, block larger-diameter particulate matter and organic matter, but allow heavy metal ions to pass through, thus extending the service life of the chip.

[0070] Example 6:

[0071] In this embodiment, the preparation method of the chip in Example 5 includes the following steps:

[0072] S01. Take a 4-inch silicon oxide wafer with a thickness of 300 nm;

[0073] S02. Magnetron sputter the chromium layer 101, gold layer 102, and titanium layer 103;

[0074] S03. Plasma-enhanced chemical vapor deposition of the SiO2 layer 104;

[0075] S04. Reactive ion etching of the SiO2 layer 104 to obtain the gold electrode holes 105;

[0076] S05. Etch the chromium layer 101 to obtain the gold electrode holes 105 and expose the gold;

[0077] S06. Remove the glue and clean.

[0078] Example 7:

[0079] In this embodiment, the marine ecological multi-parameter in-situ detection chip includes any one of the heavy metal detection chip modules 1 in Examples 1, 2, 3, 4, and 5, and further includes:

[0080] A temperature detection chip module 2, a pH detection chip module 3, and a photoresist plate 4; wherein the detection areas of the heavy metal detection chip module 1, temperature detection chip module 2, and pH detection chip module 3 are 4×2 mm 2 .

[0081] The heavy metal detection chip module 1, temperature detection chip module 2, and pH detection chip module 3 are arranged on the photoresist plate 4, and the distance between each module is 200 nm.

[0082] Among them, the temperature detection chip module 2 uses a platinum electrode to achieve the detection function. The main body of the platinum electrode is a platinum wire array with a line width of 50 μm, a line length of 36 mm, and a distance of 200 μm between Pt wires, separated by a SiO2 layer; the surrounding is a SU-8 photoresist with a width of 250 μm and a thickness of 150 μm, separating the temperature detection area from the detection areas of other parameters. When performing temperature detection, the Pt metal layer is directly in contact with seawater, and the resistance value of the Pt wire array changes with the seawater temperature.

[0083] Among them, the size of the pH detection area in the pH detection chip module 3 is 4.5×2.5 mm2, and the main body is 4×2 mm 2 of the Pt electrode. The surrounding is SU-8 photoresist with a width of 250 μm and a thickness of 150 μm, which separates the pH detection area from the detection areas of other parameters. In addition, the surface of the platinum electrode needs to be treated to increase its responsiveness and stability to hydrogen ions. Common surface treatment methods include electrochemical oxidation or reduction treatment to form a stable oxide layer or reduction layer.

[0084] In a preferred solution, the pH detection chip module 3 further includes a sensitive film. When performing pH detection, ruthenium oxide is deposited on the Pt electrode as the sensitive film and is in direct contact with seawater.

[0085] During use, the heavy metal detection chip module 1, the temperature detection chip module 2, and the pH detection chip module 3 are integrated into one chip to achieve multi-parameter detection, as Figure 1 shown.

[0086] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention belong to the scope of protection required by the present invention.

Claims

1. An in-situ detection chip for multiple marine ecological parameters, characterized in that, It includes a heavy metal detection chip module (1). The heavy metal detection chip module (1) sequentially includes a chromium layer (101), a gold layer (102), and a titanium layer (103) from top to bottom. Among them, the thickness of the chromium layer (101) is 5 - 10 nm, the thickness of the gold layer (102) is 50 - 60 nm, and the thickness of the titanium layer (103) is 5 - 10 nm. The heavy metal detection chip module (1) further includes a SiO2 layer (104) located above the chromium layer (101). The heavy metal detection chip module (1) also includes a number of gold electrode holes (105) provided on the chromium layer (101) and the SiO2 layer (104). The diameter of the gold electrode holes (105) is 5 - 6 μm. The distance between the centers of the gold electrode holes (105) is 200 - 250 μm. The heavy metal detection chip module (1) also includes a sensitive film (106) provided on the gold electrode holes (105). The sensitive film (106) is mercury. The heavy metal detection chip module (1) also includes a gel protective film (107) provided on the SiO2 layer (104) and covering the sensitive film (106). The gel protective film (107) is agar.

2. The in-situ detection chip for multiple marine ecological parameters according to claim 1, characterized in that, The detection area of the heavy metal detection chip module (1) is (4000~5000)×(2000~3000) μm 2 .

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