Full-automatic electrochemical luminescence detector based on photodiode

Abstract

The invention discloses a full-automatic electrochemical luminescence detector based on a photodiode, and relates to an electrochemical luminescence detector, the full-automatic electrochemical luminescence detector comprises a shell, the shell is internally provided with an optical signal acquisition module, a small packaging circuit board, an ECL chip, a man-machine interaction module and a chip inlet and outlet device; a light current detection unit, an electrochemical reaction excitation unit and a microcontroller are arranged in the small packaging circuit board; wherein a test strip sample pad and a reaction area are arranged in the ECL chip. The photodiode used in the invention can make a quick response to the change of light intensity, which is far faster than the frame capturing speed of the camera, and the demand and complexity of subsequent data processing are reduced, so that the system is easier to realize automation. Compared with a camera, the photodiode is lower in hardware cost, does not need to use complex image processing software, and is suitable for household use. The detector is compact in structure, small and exquisite in appearance and convenient to use in a handheld mode and carry about.

Description

Technical Field

[0001] The present invention relates to an electrochemiluminescence detection instrument, and more particularly to a full-automatic electrochemiluminescence detection instrument based on a photodiode. Background Art

[0002] ECL is a technology that generates and detects light signals based on electrochemical reactions. It combines the advantages of electrochemistry and chemiluminescence, offering high sensitivity, a wide linear range, good stability, and selectivity. ECL technology typically requires specialized detectors, which typically include modules for electrochemical reaction excitation, optical signal detection, and data processing.

[0003] Currently, the most common ECL signal detection method uses CCD and CMOS imaging for analysis. Image processing techniques are used to preprocess, filter, enhance, and extract features from camera-captured images to reduce noise, improve image quality, and extract target information. These operations typically rely on specialized image processing software or algorithms, which requires high-level image processing skills. Such instruments are generally large, difficult to port, and expensive, making them unsuitable for home use. Specifically, their shortcomings are mainly reflected in:

[0004] 1. The electrochemical reaction excitation unit of a traditional ECL detector generally controls the excitation voltage by manually adjusting the resistor or knob. The steps are cumbersome and the excitation voltage is often difficult to control accurately, which causes errors in each test due to different excitation voltages.

[0005] 2. Traditional ECL detectors use cameras to shoot, extract video frames, and perform complex calculations to obtain test results. This requires the use of computers, mobile phones, Raspberry Pi and other devices to process data, which increases the cost and size of the detector.

[0006] 3. For traditional ECL detectors, the amount of image analysis data is large, and it takes tens of seconds or even minutes from the start to the end of the test, which is relatively cumbersome to operate.

[0007] 4. Traditional ECL detectors require a built-in camera, so the overall size of the instrument is large and cannot be carried around or used handheld.

[0008] In recent years, photodiodes have been widely used in various sensing systems, perhaps due to their advantages such as low price, high sensitivity, fast response, and miniaturization. Integrating photodiodes into ECL detection systems not only significantly reduces system complexity and cost but also increases detection speed, providing a new solution for fully automated immuno-ECL detection.

[0009] Despite this, it remains extremely challenging to design an efficient and reliable photodiode-based fully automatic ECL detector and ensure its good performance in actual immunoassay applications. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to address the deficiencies of the existing technology and to provide an ECL detector with a simple structure, convenient operation and high cost performance to meet the growing needs of clinical diagnosis, home self-examination, etc.

[0011] The photodiode-based fully automatic electrochemiluminescence detector of the present invention comprises a housing, wherein the housing is provided with a light signal acquisition module, a small package circuit board, an ECL chip, a human-computer interaction module, and a chip access device; the small package circuit board is provided with a photocurrent detection unit, an electrochemical reaction excitation unit, and a microcontroller; wherein the ECL chip is provided with a test strip sample pad, a detection pad, and a connection pad;

[0012] The fully automatic electrochemiluminescence detector includes the following steps:

[0013] The first step is to drop a certain amount of sample solution onto the sample pad of the test strip and wait for the set immune response time;

[0014] Step 2: adding a first amount of PBS to the test strip sample pad to wash away the residue;

[0015] Step 3: adding a second amount of PBS to the connection pad;

[0016] The fourth step is to install the ECL chip in the shell, and send an excitation voltage parameter selection instruction to the microcontroller through the human-computer interaction module, so that the microcontroller sends the set excitation voltage parameters to the electrochemical reaction excitation unit. The electrochemical reaction excitation unit generates an excitation voltage according to the excitation voltage parameters and provides the excitation voltage to the chip input and output device to power the ECL chip, so that the sample solution undergoes ECL reaction; the photocurrent detection unit collects the photoelectric signal generated by the ECL reaction in the reaction area on the detection pad, and transmits the photoelectric signal to the photocurrent detection unit. The photocurrent detection unit converts the photoelectric signal into a digital signal and transmits it to the human-computer interaction module through the microcontroller.

[0017] Preferably, the electrochemical reaction excitation unit includes a same-direction amplifier circuit, a voltage stabilizing circuit, a DAC circuit and a reference voltage circuit; the voltage stabilizing circuit is connected to the power input end of the same-direction amplifier circuit; the reference voltage circuit is connected to the power input end of the DAC circuit, the DAC circuit receives the excitation voltage parameter and outputs an output voltage, the same-direction amplifier circuit amplifies the output voltage of the DAC circuit and uses the amplified voltage as the excitation voltage.

[0018] Preferably, the chip entry and exit device includes a front-end spring, an elastic contact piece, a guide rail and a rear-end baffle; the guide rail is fixed to the bottom of the shell, and an ECL chip inlet and outlet are opened at one end of the shell, the ECL chip is inserted into the ECL chip inlet and outlet, and the ECL chip is slidably installed on the guide rail; a front-end spring is installed in the shell at the end of the guide rail, and the end of the front-end spring is connected to the ECL chip, and an elastic contact piece is also installed in the shell, and the elastic contact piece is connected to the output end of the electrochemical reaction excitation unit through a wire, and the ECL chip is provided with a conductor in contact with the elastic contact piece, and a rear-end baffle for locking the ECL chip is slidably installed at the end of the shell away from the front-end spring.

[0019] Preferably, the optical signal acquisition module includes a photodiode and a light-shielding box; the light-shielding box is fixed in the housing, the bottom of the light-shielding box is open, and the bottom of the light-shielding box is facing the reaction area on the detection pad of the ECL chip; the photodiode is installed in the light-shielding box to collect the photoelectric signal generated by the ECL reaction.

[0020] Preferably, the photocurrent detection unit includes a transimpedance amplifier circuit, a reverse amplifier circuit, a common-direction amplifier circuit, an active filter circuit and an ADC circuit; the photodiode amplifies the collected photoelectric signal through the transimpedance amplifier circuit, the reverse amplifier circuit and the common-direction amplifier circuit in sequence, and then filters it through the active filter circuit to remove high-frequency noise, and then samples and quantizes it into a digital signal through the ADC circuit and transmits it to the microcontroller.

[0021] Preferably, the shell includes an upper cover and a base; four protruding pins are provided at the lower end of the upper cover, and the four pins are respectively inserted into the four end corners of the small package circuit board; the base is provided with four hollow columns, and the four hollow columns correspond to the four pins one by one, so that when the upper cover and the base are closed, the hollow columns and the pins form a hole-axis fit.

[0022] Preferably, the light shielding box, upper cover and base are all made of black polylactic acid (PLA) material.

[0023] Preferably, the human-computer interaction module includes a start button, a review button, a setting button, a power switch and a display screen, and the start button, review button, setting button, power switch and display screen are all embedded in the upper cover.

[0024] Preferably, the small package circuit board is further provided with a memory, and the memory is electrically connected to the microcontroller.

[0025] Preferably, a serial port chip is further provided in the small package circuit board, one end of the serial port chip is electrically connected to the microcontroller, and the other end of the serial port chip communicates with an external device through an external interface.

[0026] Beneficial effects

[0027] The advantages of the present invention are:

[0028] 1. The photodiode used in the present invention can respond quickly to changes in light intensity. Its response time is usually in the nanosecond to microsecond level, which is much faster than the speed at which the camera captures frames. This is particularly important for real-time monitoring or applications that require fast response.

[0029] 2. Compared with instruments using cameras, the detector of the present invention requires less signal data to be processed, which reduces the complexity of subsequent data processing and makes the system easier to automate; it only takes a few seconds from clicking the start button to displaying the test results.

[0030] 3. The present invention uses a photodiode as a light-sensitive element, which greatly reduces the cost of the detector. Compared with a camera, the photodiode hardware cost is lower and does not require the use of complex image processing software, making it suitable for home use.

[0031] 4. The present invention makes the detector compact in appearance through the design of a small package circuit board and a compact shell structure, making it easy to use as a handheld device and carry around. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a half-section diagram of the fully automatic electrochemiluminescence detector based on a photodiode of the present invention.

[0033] Figure 2 This is a bottom view of the upper cover structure of the fully automatic electrochemiluminescence detector based on photodiodes of the present invention.

[0034] Figure 3 This is a schematic diagram of the boost circuit of the power module of the present invention.

[0035] Figure 4 This is a schematic diagram of the charging circuit of the power module of the present invention.

[0036] Figure 5This is a schematic diagram of the linear regulator circuit of the power module of the present invention.

[0037] Figure 6 This is a schematic diagram of the boost circuit of the electrochemical excitation unit of the present invention.

[0038] Figure 7 This is a schematic diagram of the voltage output circuit of the electrochemical excitation unit of the present invention.

[0039] Figure 8 This is a circuit diagram of the photocurrent detection module of the present invention.

[0040] Figure 9 2 is a circuit diagram of the active filter circuit of the present invention.

[0041] Figure 10 4 is a circuit diagram of the ADC circuit of the present invention.

[0042] Figure 11 The microcontroller and its peripheral circuit schematic diagram of the present invention.

[0043] Figure 12 FIG. 4 is a circuit schematic diagram of the memory circuit of the present invention.

[0044] Figure 13 This is a circuit schematic diagram of the serial communication circuit of the present invention.

[0045] Figure 14 The figure is a curve diagram of the detection results of the detector of the present invention when detecting luteinizing hormone (LH).

[0046] Among them: photodiode 11; light shield 12; circuit board 2; photocurrent detection unit 21; electrochemical reaction excitation unit 22; microcontroller 23; power module 24; memory chip 25; serial communication chip 26; ELC chip 3; test strip sample pad 31; test strip detection pad 32; connection pad 33; start button 41; review button 42; setting button 43; power switch 44; display screen 45; top cover 51; base 52; pin 53; hollow column 54; front spring 61; elastic contact piece 62; guide rail 63; rear baffle 64. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with the embodiments, but this does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0048] See Figure 1-Figure 2The present invention discloses a fully automatic electrochemical luminescence detector based on a photodiode, comprising an optical signal acquisition module 1, a small package circuit board 2, an ECL chip 3, a human-computer interaction module 4, a housing 5, and a chip access device 6. The optical signal acquisition module 1 comprises a photodiode 11 and a light shielding box 12; the small package circuit board 2 comprises a photocurrent detection unit 21, an electrochemical reaction excitation unit 22, a microcontroller 23, a power module 24, a memory 25, and a serial port chip 26; the human-computer interaction module 4 comprises a start button 41, a review button 42, a setting button 43, a power switch 44, and a display screen 45; the housing 5 comprises an upper cover 51 and a base 52; and the chip access device 6 comprises a front spring 61, an elastic contact piece 62, a guide rail 63, and a rear baffle 64.

[0049] The ECL chip 3 is inserted into and fixed in the detector through the chip insertion and extraction device 6 in the housing 5; the power module 24 supplies power to the detector; after turning on the power switch 44, clicking the start button 41 on the human-computer interaction module 4 starts the fully automatic detection process, and the detection results are automatically displayed on the display screen 45.

[0050] Specifically, after clicking Start button 41, microcontroller 23 first transmits the set excitation voltage parameters to the digital-to-analog converter (DAC) chip in electrochemical reaction excitation unit 22 via serial peripheral interface (SPI) communication. Upon receiving the instruction from microcontroller 23, the DAC chip outputs a specified voltage, which is amplified by the amplifier circuit to become the excitation voltage. The excitation voltage is then supplied to the drive electrodes on ECL chip 3 via the wires between chip inlet and outlet device 6 and the amplifier circuit, and the elastic contacts 62 thereon, thereby triggering the ECL reaction. Photodiode 11 in optical signal acquisition module 1 receives the ECL signal, converts it into a photoelectric signal, and transmits it via wires to photocurrent detection unit 21. The photoelectric signal is converted into a corresponding voltage signal through the transimpedance amplifier circuit in the photocurrent detection unit 21. The voltage signal passes through the reverse amplifier circuit, the same-direction amplifier circuit and the filter circuit in the photocurrent detection unit 21 in sequence. The filtered voltage signal is quantized into a digital signal by the analog-to-digital conversion (ADC) chip, and then sent to the microcontroller 23 through the bidirectional two-wire synchronous serial bus (I2C) protocol for digital filtering processing; the peak value of the processed signal is calculated and sent to the display screen 45 through SPI communication. The display screen 45 refreshes and displays the currently received data in real time. When the displayed data stabilizes and remains unchanged, it is the detection result. The microcontroller 23 stores the detection result in the memory 25, and a fully automatic detection process is completed.

[0051] The following is a detailed introduction to the various parts that make up this detector.

[0052] Regarding the power module 24, it can be powered by an external 5V power supply through the USB interface, or it can be powered by a battery; the power module 24 has a switching circuit, which switches to battery power when there is no 5V power supply connected; when powered by the battery, the input voltage is boosted and stabilized to 5V through the power module 24; when an external 5V power supply is connected, the battery is charged through the lithium battery charging management chip; the linear regulator steps down the 5V voltage output by the power module 24 to 3.3V to power the microcontroller 23.

[0053] Specifically, see Figure 3 、 Figure 4 and Figure 5 The power module 24 mainly includes three parts. In this module, the boost chip is TPS61023, and the power module 24 contains a 10μF and a 4.7μF chip capacitor, a 732kΩ and a 100kΩ chip resistor, and a 2.2μH chip capacitor; the lithium battery charging management chip is TP4057, and its circuit contains two 10μF chip capacitors and a 2kΩ chip resistor; the linear regulator chip is AMS1117-3.3, and its circuit contains two 22μF chip capacitors and two 100nF chip capacitors.

[0054] The electrochemical reaction excitation unit 22 includes a non-inverting amplifier circuit, a boost circuit, a DAC circuit, and a reference voltage circuit. The boost circuit boosts the 5V voltage provided by the power module 24 to 24V to power the operational amplifier in the non-inverting amplifier circuit. The reference voltage circuit provides a 4.096V reference voltage to the DAC circuit, which then provides a programmable output voltage between 0V and 4.096V. The non-inverting amplifier circuit amplifies the DAC circuit output voltage to achieve a programmable 0-22V excitation voltage output.

[0055] Specifically, see Figure 6 The chip used for the BOOST boost circuit is TPS61175. The boost circuit includes a 10μF chip capacitor, two 47nF chip capacitors, two 4.7μF chip capacitors, a 3.16kΩ chip resistor, a 16.2kΩ chip resistor, a 300kΩ chip resistor, a 121kΩ chip resistor, a 15μH chip inductor, and an SS54 diode. Figure 7As shown in the figure, the reference voltage circuit consists of three parts. The chip used in its front end is REF5040, and its peripheral circuit includes two 1μF chip capacitors and one 22μF chip capacitor; the chip selected for the DAC circuit is DAC7311, which includes two 22Ω chip resistors as SPI series resistance, a 100nF chip capacitor and a 10μF chip capacitor; the operational amplifier selected for the in-phase amplifier circuit is LM2094, and the amplifier circuit includes a 100nF chip capacitor, an 8.2kΩ chip resistor, a 10kΩ chip resistor and a 40kΩ chip resistor.

[0056] The photocurrent detection unit 21 includes a transimpedance amplifier circuit, an inverse amplifier circuit, a common-direction amplifier circuit, an active filter circuit, and an ADC circuit. The photocurrent generated by the photodiode 11 is amplified in sequence by the transimpedance amplifier circuit, the inverse amplifier circuit, and the common-direction amplifier circuit, and then filtered by the active filter circuit to remove high-frequency noise. The photocurrent is then sampled and quantized into a digital signal by the ADC circuit and transmitted to the microcontroller 23.

[0057] Since the test strip detection pad 32 on the ECL chip 3 of this embodiment has two reaction areas, it is necessary to set up two-channel amplifier circuits and active filter circuits in the photocurrent detection unit 21, as shown in FIG. Figure 8 and Figure 9 As shown. Figure 8 The figure shows the schematic diagram of a two-channel amplifier circuit. The amplifier circuit is composed of a multi-stage AD866X series operational amplifier. The transimpedance amplifier circuit uses a single-channel AD8661 chip, and the reverse amplifier circuit and the same-direction amplifier circuit each use one channel of the dual-channel AD8662 chip. The amplifier circuit also contains two 100nF chip capacitors, three 8pF chip capacitors, two 10kΩ chip resistors, three 1kΩ chip resistors, one 20kΩ chip resistor, and one 51kΩ chip resistor. Figure 9 As shown in the figure, the active filter circuit uses the AD8656 chip as the op amp chip, and contains a 2.37kΩ chip resistor, a 4.87kΩ chip resistor, a 1.58kΩ chip resistor, two 100nF chip capacitors, and a 22nF chip capacitor. The above amplifier circuit and active filter circuit are configured for one photocurrent detection channel. The configuration of the other channel is the same and will not be repeated here. Figure 10 As shown in the figure, the ADC circuit uses the ADS1115 chip, which includes two 10kΩ pull-up resistors and a 100nF chip capacitor.

[0058] See also Figure 11Microcontroller 23 uses a 32-bit microcontroller chip, specifically the STM32L431. Its peripheral circuits include a power supply circuit, a reset circuit, a crystal oscillator circuit, a debug interface circuit, and a boot circuit. The power supply circuit uses a 3.3V linear regulator connected to the microcontroller's VDD pin. The reset circuit, consisting of a 10kΩ chip resistor and a 1μF chip capacitor, provides a reset function for microcontroller 23. The crystal oscillator circuit uses an 8MHz crystal oscillator to provide a clock for microcontroller 23, with a 20pF load capacitor connected in parallel to each of the two crystal oscillator pins. The debug interface circuit uses a 1*4P pin header for debugging and burning programs. The boot circuit uses BOOT0 connected in series with a 510Ω resistor and then grounded, serving as the default boot circuit.

[0059] The microcontroller 23 is connected to the memory 25 and is also connected to one end of the serial port chip 26. The other end of the serial port chip 26 is connected to the USB interface, so that the detector of the present invention can communicate with external devices that support USB (such as computers and mobile phones) through the serial port chip 26 to achieve two-way data transmission.

[0060] Specifically, see Figure 12 The memory 25 uses an AD24C02 chip, which communicates with the microcontroller 23 via I2C for data storage, and its peripheral circuit includes two 10kΩ pull-up resistors. Figure 13 As shown, the serial port chip 26 adopts CH340N, and its peripheral circuit includes two 100nF chip capacitors.

[0061] like Figure 1 As shown, in the human-computer interaction module 4, a start button 41, a review button 42, a settings button 43, a power switch 44, and a display screen 45 are all embedded in the upper cover 51. Display screen 45 is 1.8 inches in size and communicates with the microcontroller 23 via the SPI protocol. Start button 41 is connected to the GPIO port of the microcontroller 23 through a debouncing circuit composed of a 100nF chip capacitor and a 10kΩ chip resistor. The start button 41 starts the detection process, the query button 42 queries the historical record, and the settings button 43 selects the excitation voltage level pre-stored in the memory 25.

[0062] The front spring 61, elastic contact 62, and guide rail 63 of the chip entry and exit device 6 are located on the base 52. The front spring 61 and rear baffle 64 are used to secure the ECL chip 3 to a designated position, so that the light-shielding box 12 and the two photodiodes 11 are respectively facing the observation window of the ECL chip 3. Specifically, an ECL chip inlet and outlet are provided at one end of the housing 5, into which the ECL chip 3 is inserted, and the ECL chip 3 is slidably mounted on the guide rail 63. A front spring 61 is mounted in the housing 5 at the end of the guide rail 63, and the end of the front spring 61 is connected to the ECL chip 3. A elastic contact 62 is also mounted in the housing 5, and the elastic contact 62 is connected to the output end of the DAC circuit via a wire. The ECL chip 3 is provided with a conductor that contacts the elastic contact 62. A rear baffle 64 for locking the ECL chip 3 is slidably mounted on the end of the housing 5 away from the front spring 61.

[0063] When the rear end baffle 64 is pushed upward, the ECL chip 3 can be inserted into the specified position along the guide rail 63, so that the elastic contact 62 is connected to the driving electrode of the ECL chip 3; when the ECL chip 3 is taken out, the rear end baffle 64 is pushed upward, and the ECL chip 3 will automatically pop out due to the tension of the front end spring 61.

[0064] See also Figure 2 The lower end of the upper cover 51 is provided with four protruding pins 53 for securing the small package circuit board 2. The base 52 is provided with four hollow pins 54, which correspond to the pins 53 of the upper cover 51. When the upper cover 51 and base 52 are closed, the hollow pins 54 and the pins 53 form a hole-axis fit, and then a certain method (such as gluing or ultrasonic bonding) is used to fix the upper and lower covers. In addition, the inner side of the base 52 is provided with a groove, and the photodiode 11 is fixed to the light shielding box 12, which is installed in the groove inside the base 52.

[0065] The housing 5 , the light shielding box 12 and the rear baffle 64 of this embodiment are all made of black polylactic acid (PLA) material, wherein the size of the housing 5 is 90 mm*50 mm*30 mm.

[0066] The following describes the use of a photodiode-based fully automatic electrochemiluminescence detector in the detection process of luteinizing hormone (LH):

[0067] First, 30 μL of a sample solution containing LH was dropped onto the sample pad 31 of the test strip and waited for 3 minutes for immune reaction.

[0068] Next, 30 μL of PBS was added dropwise to the sample pad 31 of the test strip to wash away excess residues for 3 minutes; subsequently, 20 μL of PBS was added dropwise to the connection pad 32 .

[0069] Finally, the ECL chip 3 is placed in a photodiode-based fully automatic electrochemiluminescence detector for detection. Turn on the power switch 44, click the start button 41 to start the test, and the electrochemical reaction excitation unit 22 outputs a default 11V excitation voltage to perform an ECL reaction on the test strip detection pad 32. During the reaction, the ECL signals on the T line and C line on the test strip detection pad 32 are collected by the photodiode 11 and converted into photocurrent signals. The signals are then passed through the amplifier circuit, filter circuit, and ADC in sequence. Finally, after data processing by the microcontroller 23, the peak values of the T line and C line are output to the display screen 45 respectively. The ratio of the collected signal values (T / C) is used to quantitatively detect LH.

[0070] Now contains 0mIU mL -1 , 0.1mIU mL -1 、1mIU mL -1 and 10mIU mL -1 The relationship between the concentration of LH in the sample solution and T / C and the effect of the instrument in immunoassay were tested using the sample solution of LH and the detector of the present invention as an example. Figure 14 As shown in the figure, it can be seen from the test results that: using the fully automatic electrochemiluminescence detector based on photodiode of the present invention, as the LH concentration increases, the T / C on the ECL chip 3 also increases accordingly; and in the range of 0.1-10mIU mL -1 Within the range, there is a good linear relationship between the logarithm of LH concentration and the logarithm of T / C, and the linear fitting equation is Y=0.387X+0.181, with a correlation coefficient R 2 =0.9009 (n=5). Therefore, the photodiode-based fully automatic electrochemiluminescence detector of the present invention can be applied to LH immunoassays, and can also be applied to immunoassays of biomarkers of other diseases and other physiological activities.

[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention. These modifications and improvements will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A fully automatic electrochemiluminescence detector based on a photodiode, characterized in that: The invention comprises a housing (5), wherein the housing (5) is provided with an optical signal acquisition module (1), a small package circuit board (2), an ECL chip (3), a human-computer interaction module (4), and a chip entry and exit device (6); the small package circuit board (2) is provided with a photocurrent detection unit (21), an electrochemical reaction excitation unit (22), and a microcontroller (23); wherein the ECL chip (3) is provided with a test strip sample pad (31), a detection pad (32), and a connection pad (33); The fully automatic electrochemiluminescence detector includes the following steps: The first step is to drop a quantitative sample solution onto the test strip sample pad (31) and wait for the set immune response time; Step 2: adding a first amount of PBS to the test strip sample pad (31) to wash away the residue; Step 3: adding a second fixed amount of PBS to the connection pad (33); The fourth step is to install the ECL chip (3) in the housing (5), and send an excitation voltage parameter selection instruction to the microcontroller (23) through the human-computer interaction module (4), so that the microcontroller (23) sends the set excitation voltage parameter to the electrochemical reaction excitation unit (22). The electrochemical reaction excitation unit (22) generates an excitation voltage according to the excitation voltage parameter and provides the excitation voltage to the chip input and output device (6) to power the ECL chip (3), so that the sample solution undergoes an ECL reaction; the photocurrent detection unit (21) collects the photoelectric signal generated by the ECL reaction in the reaction area on the detection pad (32), and transmits the photoelectric signal to the photocurrent detection unit (21). The photocurrent detection unit (21) converts the photoelectric signal into a digital signal and transmits it to the human-computer interaction module (4) through the microcontroller (23).

2. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 1, characterized in that: The electrochemical reaction excitation unit (22) comprises a same-direction amplifier circuit, a voltage stabilizing circuit, a DAC circuit and a reference voltage circuit; the voltage stabilizing circuit is connected to the power input end of the same-direction amplifier circuit; the reference voltage circuit is connected to the power input end of the DAC circuit; the DAC circuit receives an excitation voltage parameter and outputs an output voltage; the same-direction amplifier circuit amplifies the output voltage of the DAC circuit and uses the amplified voltage as the excitation voltage.

3. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 2, characterized in that: The chip entry and exit device (6) comprises a front spring (61), an elastic contact piece (62), a guide rail (63) and a rear baffle (64); the guide rail (63) is fixed to the bottom of the shell (5); an ECL chip inlet and outlet are provided at one end of the shell (5); the ECL chip (3) is plugged into the ECL chip inlet and outlet, and the ECL chip (3) is slidably mounted on the guide rail (63); a front spring (61) is installed in the shell (5) at the end of the guide rail (63); the end of the front spring (61) is connected to the ECL chip (3); an elastic contact piece (62) is also installed in the shell (5); the elastic contact piece (62) is connected to the output end of the electrochemical reaction excitation unit (22) through a wire; a conductor is provided on the ECL chip (3) in contact with the elastic contact piece (62); a rear baffle (64) for locking the ECL chip (3) is slidably mounted at one end of the shell (5) away from the front spring (61).

4. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 1, characterized in that: The optical signal acquisition module (1) comprises a photodiode (11) and a light shielding box (12); the light shielding box (12) is fixed in a housing (5), the bottom of the light shielding box (12) is open, and the bottom of the light shielding box (12) faces the reaction area on the detection pad (32) of the ECL chip (3); the photodiode (11) is installed in the light shielding box (12) and is used to collect the photoelectric signal generated by the ECL reaction.

5. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 4, characterized in that: The photocurrent detection unit (21) comprises a transimpedance amplifier circuit, a reverse amplifier circuit, a unidirectional amplifier circuit, an active filter circuit and an ADC circuit; the photodiode (11) amplifies the collected photoelectric signal in sequence through the transimpedance amplifier circuit, the reverse amplifier circuit and the unidirectional amplifier circuit, then filters the signal through the active filter circuit to remove high-frequency noise, and then samples and quantizes the signal into a digital signal through the ADC circuit and transmits the signal to the microcontroller (23).

6. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 4, characterized in that: The shell (5) includes an upper cover (51) and a base (52); four protruding pins (53) are provided at the lower end of the upper cover (51), and the four pins (53) are respectively inserted into the four end corners of the small package circuit board (2); the base (52) is provided with four hollow columns (54), and the four hollow columns (54) correspond to the four pins (53) one by one, so that when the upper cover (51) and the base (52) are closed, the hollow columns (54) and the pins (53) form a hole-axis fit.

7. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 6, characterized in that: The light shielding box (12), the upper cover (51) and the base (52) are all made of black polylactic acid (PLA) material.

8. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 6, characterized in that: The human-computer interaction module (4) includes a start button (41), a review button (42), a setting button (43), a power switch (44) and a display screen (45), and the start button (41), the review button (42), the setting button (43), the power switch (44) and the display screen (45) are all embedded in the upper cover (51).

9. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 1, characterized in that: The small package circuit board (2) is further provided with a memory (25), and the memory (25) is electrically connected to the microcontroller (23).

10. The fully automatic electrochemiluminescence detector based on a photodiode according to claim 1, characterized in that: The small package circuit board (2) is further provided with a serial port chip (26), one end of the serial port chip (26) is electrically connected to the microcontroller (23), and the other end of the serial port chip (26) communicates with an external device through an external interface.

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