A minimally invasive in vivo detection device and method for vitamin C in plant fruits

Abstract

This invention discloses a minimally invasive in vivo detection device and method for vitamin C in plant fruits. The device includes a shell, a negative pressure detection zone, a guide tube, a screen-printed electrode, an electrochemical signal detector, and an air pump. The negative pressure detection zone is located at the upper end of the shell and is connected to the air inlet of the air pump, which is located inside the shell. The screen-printed electrode is disposed on the negative pressure detection zone and connected to the electrochemical signal detector. The lower end of the guide tube is connected to the negative pressure detection zone and is used to insert into the plant fruit to extract sap and guide the sap onto the screen-printed electrode. This minimally invasive in vivo detection device can achieve high accuracy, simple operation, improved detection efficiency, reduced detection costs, and full-cycle detection of vitamin C in plant fruits.

Description

Technical Field

[0001] This invention relates to the field of vitamin detection technology, specifically to a minimally invasive in vivo detection device and method for vitamin C in plant fruits. Background Technology

[0002] Vitamin C is the vitamin required in the largest quantity by the human body. It is crucial for maintaining physiological functions; a deficiency leads to scurvy, hence its other name, ascorbic acid. Vitamin C plays a regulatory role in redox metabolism, with key physiological functions including: promoting collagen and connective tissue synthesis, accelerating wound healing; acting as a powerful antioxidant, scavenging reactive oxygen species and free radicals to protect cells from oxidative damage; enhancing immune function; preventing cancer; and promoting iron absorption. Because the human body lacks gulonolactone oxidase, it cannot synthesize vitamin C and must obtain it from food. Fruits are rich in vitamin C, and the majority of the vitamin C needed by the human body comes from fruits. Therefore, the vitamin C content of fruits is not only an important indicator of their nutritional value but also a basis for people to rationally choose and scientifically combine foods according to their nutritional needs.

[0003] Currently, there are many methods for determining vitamin C in plant fruits, mainly including 2,6-dichlorophenolindophenol titration, iodometric titration, fluorescence spectrophotometry, and high-performance liquid chromatography (HPLC). These methods all have limitations. For example, 2,6-dichlorophenolindophenol titration and iodometric titration have problems such as difficulty in determining the titration endpoint, easy oxidation of the sample extract leading to inaccurate measurements, and unsuitability for colored samples. Fluorescence spectrophotometry is cumbersome and time-consuming, and easily affected by pigments. HPLC requires expensive equipment, is cumbersome to operate, and is time-consuming. Furthermore, all of the above methods require in vitro processing of the plant fruit, including grinding, extraction, and purification, before measurement, making rapid in vivo detection impossible. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned problems and provide a live minimally invasive detection device for vitamin C in plant fruits. This live minimally invasive detection device can perform live minimally invasive detection of vitamin C in plant fruits, with high detection accuracy, simple operation, improved detection efficiency, reduced detection cost, and realization of full-cycle detection of fruit growth process.

[0005] Another objective of this invention is to provide a minimally invasive in vivo detection method for vitamin C in plant fruits.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A minimally invasive in vivo detection device for vitamin C in plant fruits includes a shell, a negative pressure detection area, a guide tube, screen-printed electrodes, an electrochemical signal detector, and an air pump; wherein,

[0008] The negative pressure detection area is located at the upper end of the housing and is connected to the air inlet of the air pump, which is located inside the housing. The screen-printed electrode is located on the negative pressure detection area and is connected to the electrochemical signal detector. The lower end of the guide tube is connected to the negative pressure detection area and is used to insert into the plant fruit to extract juice and guide the juice onto the screen-printed electrode.

[0009] The working principle of the in vivo minimally invasive detection device for vitamin C in the above-mentioned plant fruits is as follows:

[0010] Insert the upper end of the guide tube into the interior of the plant fruit to be tested about 2mm, start the air pump to create a negative pressure state in the negative pressure detection area, and the juice of the plant fruit will be drawn from the guide tube into the negative pressure detection area and fall onto the screen-printed electrode; then turn on the electrochemical signal detector to detect the vitamin C in the plant fruit; when testing the next plant fruit, replace the screen-printed electrode.

[0011] In a preferred embodiment of the present invention, the housing is provided with a cover plate for opening and closing the negative pressure detection area. The rear end of the cover plate is hinged to the housing, and the front end of the cover plate is connected to the housing via a locking mechanism. The guide tube is disposed on the cover plate. By providing the cover plate, on the one hand, it is easy to ensure the airtightness of the negative pressure detection area, thereby realizing the extraction of sap from plant fruits; on the other hand, opening the cover plate allows for convenient replacement of the screen-printed electrode.

[0012] Furthermore, the locking mechanism includes two sets of locking components symmetrically arranged on both sides of the cover plate. Each set of locking components includes a sliding block slidably disposed on the housing, a locking pin disposed on the sliding block, and a locking hole disposed on the cover plate. The locking pin and the locking hole cooperate with each other. When the cover plate needs to be opened, the sliding block is pushed, causing the sliding block to move away from the cover plate and driving the locking pin to move. The locking pin separates from the locking hole, thus opening the cover plate. When the cover plate needs to be locked and closed, after the cover plate is closed, the sliding block is pushed to move towards the cover plate and driving the locking pin to move. The locking pin inserts into the locking hole, thus locking the cover plate. The use of two sets of locking components further improves the locking effect.

[0013] Preferably, a first sealing ring for sealing the negative pressure detection area and a second sealing ring for sealing the juice are provided between the cover plate and the housing; the second sealing ring is located inside the first sealing ring, and the position of the second sealing ring corresponds to the position of the screen-printed electrode; the internal space of the second sealing ring is the detection area, and the lower end of the guide tube is connected to the detection area; the space between the outside of the second sealing ring and the inside of the first sealing ring is the negative pressure area, and the air inlet of the air pump is connected to the negative pressure area; the upper end of the second sealing ring is provided with multiple connecting grooves, which connect the detection area and the negative pressure area. In the above structure, the multiple connecting grooves on the second sealing ring connect the detection area and the negative pressure area, ensuring the negative pressure in the detection area, thereby drawing the juice into the detection area inside the second sealing ring through the guide tube, allowing the screen-printed electrode to detect the juice in the detection area; the second sealing ring ensures that the juice does not leak out of the detection area, and also ensures the accuracy of the detection results.

[0014] Preferably, the bottom of the negative pressure detection area is provided with a mounting groove, and the screen-printed electrode is mounted on the mounting groove. With the above structure, the installation of the screen-printed electrode is convenient by providing the mounting groove, and after installation, the screen-printed electrode can remain flush with the bottom of the detection area, resulting in a compact structure while also ensuring the airtightness of the second sealing ring.

[0015] Preferably, the screen-printed electrode adopts a three-electrode system, which includes a counter electrode, a working electrode, and a reference electrode arranged sequentially. The counter electrode, working electrode, and reference electrode extend to their ends by brushing on conductive silver paste, forming three signal transmission contacts. The three signal transmission contacts are connected to the electrochemical signal detector. The above structure, employing a three-electrode system, features simple structure and high measurement accuracy.

[0016] Preferably, the counter electrode is formed by brushing on carbon paste and then drying; the working electrode is formed by brushing on carbon paste doped with carbon nanotubes and then drying; and the reference electrode is formed by brushing on silver paste and then drying. In the above structure, the screen-printed electrode has advantages such as simple structure, simple manufacturing process, flexible design, good consistency, low cost, and ease of large-scale production.

[0017] Preferably, the negative pressure detection area is provided with three copper pillars, and the cover plate is provided with two sets of spring pins; each set of spring pins has three spring pins; the positions of the three spring pins in the first set correspond one-to-one with the positions of the three signal transmission contacts; the positions of the three spring pins in the second set correspond one-to-one with the positions of the three copper pillars; when the cover plate is closed, the three spring pins in the first set are in contact with the three signal transmission contacts, and the three spring pins in the second set are in contact with the three copper pillars; the side of the housing is provided with an electrochemical signal transmission interface, which is used to connect to the electrochemical signal detector; the three spring pins in the first set and the three spring pins in the second set, and the three copper pillars and the electrochemical signal transmission interface are all connected by signal lines. During testing, first insert the signal cable plug of the electrochemical signal detector into the electrochemical signal transmission interface. After closing the cover, the air pump starts working, and the juice of the plant fruit is drawn into the negative pressure detection area through the guide tube, falling onto the screen-printed electrode. The electrochemical signal generated by the screen-printed electrode is transmitted from the three signal transmission contacts to the three spring pins of the first group, and then through the signal cable to the three spring pins of the second group. After passing through the three copper pillars, it is transmitted again through the signal cable to the electrochemical signal transmission interface, and finally to the electrochemical signal detector; thus realizing the detection of vitamin C in plant fruit.

[0018] Preferably, the negative pressure detection area is provided with an air extraction port; the upper end of the air extraction port is connected to the negative pressure area, and the lower end of the air extraction port is connected to the air inlet of the air pump through a pipe. In the above structure, when the air pump operates, it extracts the air from the negative pressure area, so that the negative pressure area and the detection area form a negative pressure, which facilitates the extraction of sap from plant fruits.

[0019] Preferably, the housing is provided with a circuit mechanism for controlling the operation of the air pump. The circuit mechanism includes a start switch, a power supply module, and a running indicator light. The running indicator light and the air pump are connected in parallel to form an air pump module. The start switch, air pump module, and power supply module are connected in series. The power supply module includes a power supply interface and a power indicator light. The power supply interface and power indicator light are connected in parallel. In this structure, the power supply interface can be connected to a power cord to provide power to the running indicator light, air pump, and power indicator light. The running indicator light indicates the air pump's operating status, and the power indicator light indicates the power supply status. During detection, the start switch is controlled to turn the air pump on and off, thereby enabling the negative pressure detection zone to absorb juice.

[0020] A minimally invasive in vivo detection method for vitamin C in plant fruits, comprising the following steps:

[0021] (1) Insert the power cord into the power supply interface to provide power to the live minimally invasive detection device;

[0022] (2) Insert the signal cable plug of the electrochemical signal detector into the electrochemical signal transmission interface to connect the electrochemical signal detector to the screen-printed electrode;

[0023] (3) Open the locking mechanism, and then open the cover plate;

[0024] (4) Place the screen-printed electrode into the negative pressure detection area;

[0025] (5) Close the cover plate and shut off the locking mechanism to lock the cover plate;

[0026] (6) Insert the guide tube 2 mm into the interior of the fruit of the plant to be tested;

[0027] (7) Press the start switch, the air pump works, which creates a negative pressure state in the negative pressure detection area. The juice of the plant fruit will be drawn into the negative pressure detection area from the guide tube and fall onto the screen printing electrode. Then release the start switch and the air pump stops working.

[0028] (8) Turn on the electrochemical signal detector to detect the vitamin C in the juice.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. The in vivo minimally invasive detection device of the present invention inserts the upper end of the guide tube into the interior of the plant fruit to be tested about 2mm during detection, and obtains the juice in the plant fruit through negative pressure; by combining screen-printed electrodes with an electrochemical signal detector, the detection of vitamin C in the plant fruit is realized, which has high detection accuracy, simple operation, improved detection efficiency and reduced detection cost.

[0031] 2. The live minimally invasive detection device of the present invention uses an electrochemical sensor based on screen-printed electrodes to achieve live detection by minimally invasively extracting a small amount of plant fruit juice, causing minimal damage to the fruit.

[0032] 3. The live minimally invasive detection device of the present invention can directly insert the guide tube into the plant fruit to obtain sap; there is no need to remove the plant fruit from the body, thus avoiding waste of the fruit.

[0033] 4. The live minimally invasive detection device of the present invention has the advantages of flexible design, simple structure, good consistency, low cost and easy mass production.

[0034] 5. The in vivo minimally invasive detection device of this invention, when used in conjunction with an electrochemical signal detector, can be set to periodically detect and analyze the vitamin C content of plant fruits, realizing full-cycle detection of the plant fruit growth process; it can promptly understand the plant's growth status and select the optimal time for fruit ripening and harvesting. Attached Figure Description

[0035] Figures 1-2 This is a schematic diagram of one specific embodiment of a minimally invasive in vivo detection device for vitamin C in plant fruits according to the present invention. Figure 1 It is a 3D image. Figure 2 This is a stereoscopic view from another perspective.

[0036] Figure 3 This is a three-dimensional structural diagram of the live minimally invasive detection device of the present invention without a cover plate.

[0037] Figure 4 This is a three-dimensional structural diagram of the cover plate in the live minimally invasive detection device of the present invention when it is in the open state.

[0038] Figure 5 This is a three-dimensional structural diagram of the live minimally invasive detection device of the present invention with the cover plate in the open state and the upper shell omitted.

[0039] Figure 6 This is a schematic diagram of the structure of the screen-printed electrode in this invention.

[0040] Figure 7 This is a schematic diagram showing the connection between the screen-printed electrode and the electrochemical signal detector in this invention.

[0041] Figure 8 This is a schematic diagram of the circuit structure in this invention. Detailed Implementation

[0042] To enable those skilled in the art to fully understand the technical solutions of the present invention, the present invention will be further described below in conjunction with embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0043] Example 1

[0044] See Figures 1-7 This embodiment discloses a minimally invasive in vivo detection device for vitamin C in plant fruits, including a shell 1, a negative pressure detection area 2, a guide tube 3, a screen-printed electrode 4, an electrochemical signal detector 5, and an air pump 6. The negative pressure detection area 2 is located at the upper end of the shell 1 and is connected to the air inlet of the air pump 6, which is located inside the shell 1. The screen-printed electrode 4 is located on the negative pressure detection area 2 and is connected to the electrochemical signal detector 5. The lower end of the guide tube 3 is connected to the negative pressure detection area 2 and is used to insert into the plant fruit to extract juice and guide the juice onto the screen-printed electrode 4.

[0045] See Figures 1-4The negative pressure detection area 2 is a tank structure, and the housing 1 includes an upper housing 1-1 and a lower housing 1-2. The negative pressure detection area 2 is disposed on the upper housing 1-1.

[0046] See Figures 1-5 The housing 1 is provided with a cover plate 7 for opening and closing the negative pressure detection area 2. The rear end of the cover plate 7 is hinged to the housing 1, and the front end of the cover plate 7 is connected to the housing 1 through a locking mechanism 8. The guide tube 3 is disposed on the cover plate 7. By providing the cover plate 7, on the one hand, it is easy to ensure the airtightness of the negative pressure detection area 2, thereby realizing the extraction of juice from plant fruits; on the other hand, opening the cover plate 7 makes it easy to replace the screen printing electrode 4.

[0047] See Figures 1-5 The locking mechanism 8 includes two sets of locking components symmetrically arranged on both sides of the cover plate 7. Each set of locking components includes a sliding block 8-1 slidably arranged on the housing 1, a locking pin 8-2 arranged on the sliding block 8-1, and a locking hole 8-3 arranged on the cover plate 7. The locking pin 8-2 and the locking hole 8-3 cooperate with each other. The sliding block 8-1 can slide left and right within a limited range to extend and retract the locking pin 8-2. When the cover plate 7 needs to be opened, push the sliding block 8-1 to move it away from the cover plate 7, which in turn moves the locking pin 8-2, separating it from the locking hole 8-3, thus opening the cover plate 7. When the cover plate 7 needs to be locked, after the cover plate 7 is closed, push the sliding block 8-1 to move it closer to the cover plate 7, which in turn moves the locking pin 8-2, inserting it into the locking hole 8-3, thus locking the cover plate 7. The two sets of locking components further improve the locking effect.

[0048] The sliding block 8-1 is disposed on the lower housing 1-2.

[0049] See Figures 1-5A first sealing ring 9 for sealing the negative pressure detection area 2 and a second sealing ring 10 for sealing the juice are provided between the cover plate 7 and the housing 1. The second sealing ring 10 is located inside the first sealing ring 9, and the position of the second sealing ring 10 corresponds to the position of the screen printing electrode 4. The internal space of the second sealing ring 10 is the detection area 11, and the lower end of the guide tube 3 is connected to the detection area 11. The space between the outside of the second sealing ring 10 and the inside of the first sealing ring 9 is the negative pressure area 12, and the air inlet of the air pump 6 is connected to the negative pressure area 12. The upper end of the second sealing ring 10 is provided with a plurality of connecting grooves 10-1, which connect the detection area 11 and the negative pressure area 12. In the above structure, the second sealing ring 10 is provided with multiple connecting grooves 10-1, so that the detection area 11 is connected to the negative pressure area 12, which can ensure the negative pressure of the detection area 11, thereby drawing the juice into the detection area 11 inside the second sealing ring 10 through the guide tube 3. The screen-printed electrode 4 can detect the juice in the detection area 11. The second sealing ring 10 can ensure that the juice does not leak out of the detection area 11, and also ensure the accuracy of the detection results.

[0050] See Figures 1-5 The volume of the detection area 11 in the second sealing ring 10 is approximately 0.15 mL; the diameter of the guide tube 3 is 0.5 mm, so that the plant fruit will not be damaged when it is detected, thus achieving minimally invasive live detection.

[0051] See Figures 1-5 The upper ends of the first sealing ring 9 and the second sealing ring 10 are both fixed on the cover plate 7. When the cover plate 7 is opened, the first sealing ring 9 and the second sealing ring 10 can also be placed on the cover plate 7, which facilitates the replacement of the screen-printed electrode 4 in the negative pressure detection area 2.

[0052] See Figures 1-5 The bottom of the negative pressure detection area 2 is provided with a mounting groove that is 30mm long, 11mm wide, and 0.3mm deep. The screen-printed electrode 4 is mounted on the mounting groove, which is located in the center of the negative pressure detection area 2. With this structure, the mounting groove facilitates the installation of the screen-printed electrode 4, and after installation, the screen-printed electrode 4 can remain flush with the bottom of the detection area 11, resulting in a compact structure while ensuring the airtightness of the second sealing ring 10.

[0053] See Figures 6-7The screen-printed electrode 4 adopts a three-electrode system, comprising a counter electrode 4-1, a working electrode 4-2, and a reference electrode 4-3 arranged sequentially from left to right. The counter electrode 4-1, working electrode 4-2, and reference electrode 4-3 extend to their ends by brushing on conductive silver paste, forming three signal transmission contacts 41. These three signal transmission contacts 41 are connected to the electrochemical signal detector 5. Each of the three signal transmission contacts 41 has a width of 1.2 mm. The screen-printed electrode 4 is 30 mm long, 11 mm wide, and 0.3 mm thick, and can be installed in the center of the negative pressure detection area 2. This three-electrode system offers advantages such as simple structure and high measurement accuracy.

[0054] See Figures 6-7 The counter electrode 4-1 is formed by brushing on carbon paste and drying; the working electrode 4-2 is formed by brushing on carbon paste doped with carbon nanotubes and drying; and the reference electrode 4-3 is formed by brushing on silver paste and drying. In the above structure, the screen-printed electrode 4 has advantages such as simple structure, simple manufacturing process, flexible design, good consistency, low cost, and ease of large-scale production.

[0055] See Figures 4-7 The negative pressure detection area 2 is provided with three copper pillars 14, and the cover plate 7 is provided with two sets of spring pins 15; each set of spring pins 15 has three spring pins 15; the positions of the three spring pins 15 in the first set correspond one-to-one with the positions of the three signal transmission contacts 41; the positions of the three spring pins 15 in the second set correspond one-to-one with the positions of the three copper pillars 14; when the cover plate 7 is closed, the three spring pins 15 in the first set are in contact with the three signal transmission contacts 41, and the three spring pins 15 in the second set are in contact with the three copper pillars 14; the side of the housing 1 is provided with an electrochemical signal transmission interface 16, which is used to connect the electrochemical signal detector 5; the three spring pins 15 in the first set and the three spring pins 15 in the second set, and the three copper pillars 14 and the electrochemical signal transmission interface 16 are all connected by signal lines 25. During testing, the signal cable plug of the electrochemical signal detector 5 is first inserted into the electrochemical signal transmission interface 16. After closing the cover plate 7, the air pump 6 starts working, and the juice of the plant fruit is drawn into the negative pressure detection area 2 from the guide tube 3 and falls onto the screen-printed electrode 4. The electrochemical signal generated by the screen-printed electrode 4 is transmitted from the three signal transmission contacts 41 to the three spring pins 15 of the first group, and then through the signal cable 25 to the three spring pins 15 of the second group. After passing through the three copper pillars 14, it is transmitted again through the signal cable 25 to the electrochemical signal transmission interface 16, and finally to the electrochemical signal detector 5; thus realizing the detection of vitamin C in plant fruit.

[0056] Furthermore, three holes are opened in the lower left of the negative pressure detection area 2 for installing the three copper pillars 14, each copper pillar 14 being 5mm long and 1.5mm in diameter.

[0057] See Figures 1-5 The negative pressure detection area 2 is equipped with an air extraction port 17; the upper end of the air extraction port 17 is connected to the negative pressure area 12, and the lower end of the air extraction port 17 is connected to the air inlet of the air pump 6 through a pipe; the air outlet of the air pump 6 is connected to the atmosphere, and the diameter of the air extraction port 17 is 4mm. In the above structure, when the air pump 6 operates, it extracts the air from the negative pressure area 12, so that the negative pressure area 12 and the detection area 11 form a negative pressure, which facilitates the extraction of sap from plant fruits.

[0058] The air pump 6 is a miniature air pump, installed inside the housing 1 by bolts 18. A shock-absorbing plate 19 is also provided between the bolts 18 and the air pump 6 to reduce vibration during operation. The miniature air pump has a diameter of 27mm, a length of 70mm, a power of 5W, and can generate a negative pressure of 0.04MPa. The pipe is a vacuum silicone tube.

[0059] See Figures 1-2 and Figure 8 The housing 1 is equipped with a circuit mechanism for controlling the operation of the air pump 6. This circuit mechanism includes a start switch 20, a power supply module, and a running indicator light 21. The running indicator light 21 and the air pump 6 are connected in parallel to form an air pump module. The start switch 20, the air pump module, and the power supply module are connected in series. The power supply module includes a power interface and a power indicator light 22. The power interface and the power indicator light 22 are connected in parallel. In this structure, the power interface can be connected to a power cord to provide power to the running indicator light 21, the air pump 6, and the power indicator light 22. The running indicator light 21 indicates the operating status of the air pump 6, and the power indicator light 22 indicates the power supply status. During detection, the start switch 20 is controlled to turn the air pump 6 on and off, thereby enabling the negative pressure detection zone 2 to absorb juice.

[0060] See Figures 1-2 and Figure 8The power supply interface includes a DC power supply interface 23 and a Type-C power supply interface 24, which are connected in parallel with the power indicator light 22. Specifically, the operation indicator light 21 is connected in parallel with the air pump 6 via a wire. One pin of the start switch 20 is connected to the positive terminal of the air pump 6, and the other pin is connected to the positive terminal of the Type-C power supply interface 24 and the power LED. The negative terminal of the air pump 6 is connected to the negative terminal of the Type-C power supply interface 24 and the power LED. Both the power indicator light 22 and the operation indicator light 21 are LED indicators and are mounted on the top surface of the upper housing 1-1. The power indicator light 22 emits red light, and the operation indicator light 21 emits green light.

[0061] See Figures 1-2 The start switch 20 is a start button, which is located on the top surface of the upper housing 1-1. When the start button is pressed, the power is turned on and when it is released, the power is turned off. Its purpose is to facilitate the control of the air pump 6 and to facilitate the extraction of plant fruit juice.

[0062] Furthermore, the rear side of the lower housing 1-2 is provided with two holes for installing the DC power supply interface 23 and the Type-C power supply interface 24; the right side of the lower housing 1-2 is provided with one hole for installing the electrochemical signal transmission interface 16.

[0063] See Figures 1-7 The working principle of the in vivo minimally invasive detection device for vitamin C in the above-mentioned plant fruits is as follows:

[0064] Insert the upper end of the guide tube 3 into the interior of the plant fruit to be tested about 2mm, start the air pump 6 to create a negative pressure state in the negative pressure detection area 2, and the juice of the plant fruit will be drawn from the guide tube 3 into the negative pressure detection area 2 and fall onto the screen-printed electrode 4; then turn on the electrochemical signal detector 5 to detect the vitamin C in the plant fruit; in order to ensure the accuracy of the detection results, the screen-printed electrode 4 is generally used as a disposable electrode, so the screen-printed electrode 4 is replaced when testing the next plant fruit.

[0065] Example 2

[0066] See Figures 1-8 This embodiment discloses a minimally invasive in vivo detection method for vitamin C in plant fruits, comprising the following steps:

[0067] (1) Insert the power cord into the power supply interface to provide power to the live minimally invasive detection device;

[0068] (2) Insert the signal line plug of the electrochemical signal detector 5 into the electrochemical signal transmission interface 16 so that the electrochemical signal detector 5 is connected to the screen-printed electrode 4.

[0069] (3) Open the locking mechanism 8, and then open the cover plate 7;

[0070] (4) Place the screen-printed electrode 4 into the negative pressure detection area 2;

[0071] (5) Close the cover plate 7 and shut off the locking mechanism 8 to lock the cover plate 7;

[0072] (6) Insert the guide tube 3 2 mm into the interior of the fruit of the plant to be tested;

[0073] (7) Press the start switch 20, the air pump 6 works, so that the negative pressure detection area 2 forms a negative pressure state, and the juice of the plant fruit will be sucked into the negative pressure detection area 2 from the guide tube 3 and fall onto the screen printing electrode 4. Then release the start switch 20 and the air pump 6 stops working.

[0074] (8) Turn on the electrochemical signal detector 5 to detect the vitamin C in the juice;

[0075] (9) After the test is completed, open the locking mechanism 8, then open the cover plate 7, replace the screen printing electrode 4, and repeat steps (5) to (8) for the next round of testing.

[0076] In this embodiment, the plant fruit being tested is tomato fruit.

[0077] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A minimally invasive in vivo detection device for vitamin C in plant fruits, characterized in that, It includes a housing, a negative pressure detection area, a flow guide tube, screen-printed electrodes, an electrochemical signal detector, and an air pump; among which, The negative pressure detection area is located at the upper end of the housing and is connected to the air inlet of the air pump, which is located inside the housing. The screen-printed electrode is located on the negative pressure detection area and is connected to the electrochemical signal detector. The lower end of the guide tube is connected to the negative pressure detection area and is used to insert into the plant fruit to extract juice and guide the juice onto the screen-printed electrode. The housing is provided with a cover plate for opening and closing the negative pressure detection area. The rear end of the cover plate is hinged to the housing, and the front end of the cover plate is connected to the housing through a locking mechanism. The guide tube is disposed on the cover plate. A first sealing ring for sealing the negative pressure detection area and a second sealing ring for sealing the liquid are provided between the cover plate and the housing; the second sealing ring is located inside the first sealing ring, and the position of the second sealing ring corresponds to the position of the screen-printed electrode; the internal space of the second sealing ring is the detection area, and the lower end of the guide tube is connected to the detection area; the space between the outside of the second sealing ring and the inside of the first sealing ring is the negative pressure area, and the air inlet of the air pump is connected to the negative pressure area; the upper end of the second sealing ring is provided with multiple connecting grooves, which connect the detection area and the negative pressure area; the upper ends of both the first and second sealing rings are fixed to the cover plate; The housing is provided with a circuit mechanism for controlling the operation of the air pump. The circuit mechanism includes a start switch, a power supply module, and a running indicator light. The running indicator light and the air pump are connected in parallel to form an air pump module. The start switch, the air pump module, and the power supply module are connected in series. The power supply module includes a power supply interface and a power indicator light. The power supply interface and the power indicator light are connected in parallel. The screen-printed electrode employs a three-electrode system, comprising a counter electrode, a working electrode, and a reference electrode arranged sequentially. The counter electrode, working electrode, and reference electrode extend to their ends by brushing on conductive silver paste, forming three signal transmission contacts. These three signal transmission contacts are connected to the electrochemical signal detector. The counter electrode is formed by brushing on carbon paste and then drying; the working electrode is formed by brushing on carbon paste doped with carbon nanotubes and then drying; the reference electrode is formed by brushing on silver paste and then drying. The negative pressure detection area is provided with three copper pillars, and the cover plate is provided with two sets of spring pins; each set of spring pins has three spring pins; the positions of the three spring pins in the first set correspond one-to-one with the positions of the three signal transmission contacts; the positions of the three spring pins in the second set correspond one-to-one with the positions of the three copper pillars; when the cover plate is closed, the three spring pins in the first set are in contact with the three signal transmission contacts, and the three spring pins in the second set are in contact with the three copper pillars; the side of the housing is provided with an electrochemical signal transmission interface, which is used to connect to the electrochemical signal detector; the three spring pins in the first set and the three spring pins in the second set, and the three copper pillars and the electrochemical signal transmission interface are all connected by signal lines.

2. The in vivo minimally invasive detection device for vitamin C in plant fruits according to claim 1, characterized in that, The locking mechanism includes two sets of locking components symmetrically arranged on both sides of the cover plate. Each set of locking components includes a sliding block slidably arranged on the housing, a locking pin arranged on the sliding block, and a locking hole arranged on the cover plate. The locking pin and the locking hole cooperate with each other.

3. The in vivo minimally invasive detection device for vitamin C in plant fruits according to claim 1, characterized in that, The bottom of the negative pressure detection area is provided with a mounting groove, and the screen-printed electrode is mounted on the mounting groove.

4. The in vivo minimally invasive detection device for vitamin C in plant fruits according to claim 1, characterized in that, The negative pressure detection area is provided with an air extraction port; the upper end of the air extraction port is connected to the negative pressure area, and the lower end of the air extraction port is connected to the air inlet of the air pump through a pipe.

5. A minimally invasive in vivo detection method for vitamin C in plant fruits, characterized in that, This method, applied to the in vivo minimally invasive detection device as described in any one of claims 1-4, includes the following steps: (1) Insert the power cord into the power supply interface to provide power to the live minimally invasive detection device; (2) Insert the signal cable plug of the electrochemical signal detector into the electrochemical signal transmission interface to connect the electrochemical signal detector to the screen-printed electrode; (3) Open the locking mechanism, and then open the cover plate; (4) Place the screen-printed electrode into the negative pressure detection area; (5) Close the cover plate and shut off the locking mechanism to lock the cover plate; (6) Insert the guide tube 2 mm into the interior of the fruit of the plant to be tested; (7) Press the start switch, the air pump works, which creates a negative pressure state in the negative pressure detection area. The juice of the plant fruit will be drawn into the negative pressure detection area from the guide tube and fall onto the screen printing electrode. Then release the start switch and the air pump stops working. (8) Turn on the electrochemical signal detector to detect the vitamin C in the juice.

Images