Portable electrochemical detection device

Abstract

The invention belongs to the technical field of electronic circuits, and particularly discloses a portable electrochemical detection device which comprises an excitation circuit, a constant potential circuit, an electrochemical sensor, a current-voltage conversion circuit and a low-pass filter circuit which are connected in sequence, the excitation circuit is used for generating control voltage; the constant potential circuit is used for applying stable bias voltage to a reference electrode and a counter electrode of the electrochemical sensor in combination with the control voltage, so that a working electrode of the electrochemical sensor generates a current signal corresponding to the concentration of an object to be detected; the current-voltage conversion circuit is used for converting the current signal into a voltage signal; and the low-pass filter circuit is used for filtering high-frequency noise in the voltage signal. The detection device has the advantages of wide range, adjustability, high precision, high accuracy, small size and the like, provides a new thought and method for trace harmful substance detection in the field of electrochemistry, and has wide application prospects in the fields of environmental monitoring, biomedical treatment, food safety and the like.

Description

Technical Field

[0001] The invention discloses a portable electrochemical detection device, belonging to the technical field of electronic circuits. Background Art

[0002] Electrochemical sensor is a sensor technology based on electrochemical principle, which detects the concentration or properties of specific substances by measuring the changes of electrical signals. It uses the direct relationship between the current, voltage or resistance generated by the electrochemical reaction and the measured substance to achieve quantitative or qualitative analysis of the substance. This technology has the advantages of high sensitivity, good selectivity and fast response speed, and has broad application prospects in environmental monitoring, biomedicine, food safety and other fields.

[0003] Existing electrochemical circuits can only achieve positive voltage regulation, but cannot achieve simultaneous regulation of negative and positive voltages, and have poor flexibility; existing electrochemical circuits use digital filtering, which has problems such as large delay, high hardware cost, and high algorithm complexity; existing electrochemical circuits use single-ended acquisition for sampling, which is prone to deviations. Summary of the invention

[0004] The purpose of the present invention is to provide a portable electrochemical detection device to solve the technical problems of poor flexibility, large delay, high cost and low precision existing in existing electrochemical circuits.

[0005] The present invention provides a portable electrochemical detection device, comprising an excitation circuit, a constant potential circuit, an electrochemical sensor, a current-voltage conversion circuit and a low-pass filter circuit connected in sequence; The excitation circuit is used to generate a control voltage; The constant potential circuit is used to apply a stable bias voltage to the reference electrode and the counter electrode of the electrochemical sensor in combination with the control voltage, so that a current signal corresponding to the concentration of the analyte is generated on the working electrode of the electrochemical sensor; The current-to-voltage conversion circuit is used to convert the current signal into a voltage signal; The low-pass filter circuit is used to filter out high-frequency noise in the voltage signal.

[0006] Preferably, the excitation circuit comprises a microprocessor and a digital-to-analog converter connected to the microprocessor; The microprocessor is used to receive an external control signal; The digital-to-analog converter is used to convert an external control signal into the control voltage.

[0007] Preferably, the constant potential circuit includes a voltage reference U3, a negative feedback loop circuit and a voltage follower circuit; The voltage reference U3 is connected to the input end of the negative feedback loop circuit and the digital-to-analog converter respectively; the output end of the negative feedback loop circuit is connected to the pair of electrodes; The voltage follower circuit includes a voltage follower U5.2, a resistor R8 and a resistor R9; The non-inverting input terminal of the voltage follower U5.2 is connected to the reference electrode, and the output terminal and the inverting input terminal of the voltage follower U5.2 are both connected to one end of the resistor R9; the other end of the resistor R9 is connected to the negative feedback loop circuit; One end of the resistor R8 is connected to the digital-to-analog converter, and the other end is connected to the negative feedback loop circuit.

[0008] Preferably, the negative feedback loop circuit comprises a voltage comparator U5.1 and a capacitor C7; The inverting input terminal of the voltage comparator U5.1 is connected to the resistor R8, the non-inverting input terminal of the voltage comparator U5.1 is connected to the output terminal of the voltage reference U3, and the output terminal of the voltage comparator U5.1 is connected to the counter electrode; One end of the capacitor C7 is connected to the non-inverting input end of the voltage comparator U5.1, and the other end is connected to the output end of the voltage comparator U5.1.

[0009] Preferably, the negative feedback loop circuit further includes a resistor R10 and a resistor R11; The resistor R10 is arranged between the output end of the voltage comparator U5.1 and the pair of electrodes; One end of the resistor R11 is connected to the counter electrode, and the other end is grounded.

[0010] Preferably, the current-to-voltage conversion circuit includes an operational amplifier U5.3, a resistor R12, a capacitor C12, a capacitor C13 and a voltage reference U4; The output end of the operational amplifier U5.3 is connected to the inverting input end of the operational amplifier U5.3 via a resistor R12 and a capacitor C13 arranged in parallel; the inverting input end of the operational amplifier U5.3 is also connected to the working electrode; The non-inverting input terminal of the operational amplifier U5.3 is connected to the voltage reference U4; the output terminal of the operational amplifier U5.3 is connected to the low-pass filter circuit, and the output terminal of the operational amplifier U5.3 is also grounded via the capacitor C12.

[0011] Preferably, the low-pass filter circuit includes a resistor R6, a resistor R7, an operational amplifier U5.4, a capacitor C14 and a capacitor C15; One end of the resistor R6 is connected to the in-phase input end of the operational amplifier U5.4, and the other end is connected to one end of the resistor R7; the other end of the resistor R7 is connected to the current-voltage conversion circuit; One end of the capacitor C14 is connected to the non-inverting input terminal of the operational amplifier U5.4, and the other end is grounded; The inverting input terminal of the operational amplifier U5.4 is connected to the output terminal of the operational amplifier U5.4, and the inverting input terminal of the operational amplifier U5.4 is also connected to one end of the capacitor C15; the other end of the capacitor C15 is connected to the resistor R6.

[0012] Preferably, it also includes an AD differential sampling circuit; The AD differential adopting circuit is connected to the low-pass filtering circuit and the microprocessor respectively, and is used for converting the voltage signal output by the low-pass filtering circuit into a digital signal and transmitting it to the microprocessor.

[0013] Preferably, it also includes a mobile terminal connected to the microprocessor; The microprocessor sends the digital signal to the mobile terminal; The mobile terminal is used to convert the digital signal into concentration information of the object to be tested and display the information.

[0014] Preferably, it also includes a power supply circuit; the power supply circuit is connected to the microprocessor.

[0015] Compared with the prior art, the portable electrochemical detection device of the present invention has the following beneficial effects: The present invention discloses a portable electrochemical detection device with a wide range, adjustable and high precision, which can be applied to the detection of substances with trace concentrations. The detection process is to use an excitation circuit and a constant potential circuit to apply a positive bias or a negative bias to the electrochemical sensor. The current generated by the electrochemical sensor under the bias is converted into a voltage by a current-voltage conversion circuit and then enters a low-pass filter circuit to filter out high-frequency noise, and then an AD differential sampling circuit is used for dual-channel sampling, and then transmitted to a microcontroller through a serial peripheral interface (SPI), and finally the detection result is sent to a smart mobile terminal through a low-power Bluetooth (BLE), and a real-time line graph is generated. The present invention has the advantages of wide range, adjustable, high precision, high accuracy, small size, etc., and can meet the portable requirements. The present invention provides a new idea and method for the detection of trace harmful substances in the field of electrochemistry, and has broad application prospects in the fields of environmental monitoring, biomedicine, food safety, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is an overall framework diagram of a portable electrochemical detection device in an embodiment of the present invention.

[0017] Figure 2 Schematic diagram of the structure of a digital-to-analog converter in a portable electrochemical detection device in an embodiment of the present invention.

[0018] Figure 3 Schematic diagram of the structure of the voltage reference U3 in the portable electrochemical detection device in the embodiment of the present invention.

[0019] Figure 4 It is a combined circuit diagram of a constant potential circuit, an electrochemical sensor, and a current-voltage conversion circuit in a portable electrochemical detection device in an embodiment of the present invention.

[0020] Figure 5 Schematic diagram of the structure of the voltage reference U4 in the portable electrochemical detection device in the embodiment of the present invention.

[0021] Figure 6 Schematic diagram of a low-pass filter circuit in a portable electrochemical detection device in an embodiment of the present invention.

[0022] Figure 7 It is a partial circuit diagram of an AD differential sampling circuit in a portable electrochemical detection device in an embodiment of the present invention.

[0023] Figure 8 It is a partial circuit diagram of an AD differential sampling circuit in a portable electrochemical detection device in an embodiment of the present invention.

[0024] Fig. 9 This is a circuit diagram of a lithium battery power supply in a portable electrochemical detection device in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0026] The embodiment of the present invention discloses a portable electrochemical detection device, the overall frame of which is as follows Figure 1As shown, it includes an excitation circuit, a constant potential circuit, an electrochemical sensor, a current-voltage conversion circuit and a low-pass filter circuit connected in sequence; wherein the electrochemical sensor is connected by three electrode parts, namely, a working electrode (WE), a reference electrode (RE) and a counter electrode (CE). The excitation circuit of the embodiment of the present invention is used to generate a control voltage; the constant potential circuit is used to apply a stable bias voltage to the reference electrode and the counter electrode of the electrochemical sensor in combination with the control voltage, so that a current signal corresponding to the concentration of the substance to be measured is generated on the working electrode of the electrochemical sensor; the current-voltage conversion circuit is used to convert the current signal into a voltage signal; and the low-pass filter circuit is used to filter out high-frequency noise in the voltage signal.

[0027] The present invention uses an excitation circuit and a constant potential circuit to achieve adjustable bias voltage. Specifically, a positive bias or a negative bias can be applied to the reference electrode and the counter electrode of the electrochemical sensor according to the control voltage of the excitation circuit and the voltage output by the voltage reference device U3 in the constant potential circuit, thereby improving its flexibility. Furthermore, the present invention uses a low-pass filter circuit instead of a digital filter, thereby greatly improving the timeliness of the filter and reducing the cost.

[0028] The excitation circuit includes a microprocessor and a digital-to-analog converter; the microprocessor and the digital-to-analog converter are connected via an integrated circuit bus (I2C), wherein the microprocessor is used to receive an external control signal; and the digital-to-analog converter is used to convert the external control signal into a control voltage.

[0029] The microprocessor in the present invention is preferably ESP32-PICO-D4, which integrates Bluetooth Low Energy (BLE) to reduce space and PCB size. The digital-to-analog converter in the embodiment of the present invention is preferably DAC8571IDGKR, which has a resolution of 16 bits, a reference voltage of 3.3V, and samples the I2C bus. The digital-to-analog converter includes Figure 2 The program-controlled voltage regulation circuit shown has a voltage buffer output type, which provides precise control voltage for the constant potential circuit and realizes the conversion between digital signals and analog signals.

[0030] The constant potential circuit in the embodiment of the present invention includes: Figure 3 The voltage reference U3 shown and Figure 4 The negative feedback loop circuit and voltage follower circuit shown in . The voltage reference U3 is connected to the input end of the negative feedback loop circuit and the pin 2 of the digital-to-analog converter respectively; the output end of the negative feedback loop circuit is connected to the counter electrode.

[0031] Specifically, the voltage follower circuit includes a voltage follower U5.2, a resistor R8 and a resistor R9; the non-inverting input terminal of the voltage follower U5.2 is connected to the reference electrode (RE) of the electrochemical sensor, and the output terminal and the inverting input terminal of the voltage follower U5.2 are both connected to one end of the resistor R9; the other end of the resistor R9 is connected to the negative feedback loop circuit, specifically to the voltage comparator U5.1 (i.e. Figure 1 One end of the resistor R8 is connected to pin 2 of the digital-to-analog converter, and the other end is connected to the negative feedback loop circuit, specifically, to the inverting input terminal of the voltage comparator U5.1 in the negative feedback loop circuit.

[0032] The negative feedback loop circuit of the embodiment of the present invention includes a voltage comparator U5.1 and a capacitor C7; wherein the inverting input terminal of the voltage comparator U5.1 is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to pin 2 of the digital-to-analog converter; the non-inverting input terminal of the voltage comparator U5.1 is connected to the output terminal of the voltage reference U3, and the output terminal of the voltage comparator U5.1 is connected to the counter electrode (CE) of the electrochemical sensor; one end of the capacitor C7 is connected to the non-inverting input terminal of the voltage comparator U5.1, and the other end is connected to the output terminal of the voltage comparator U5.1. The negative feedback loop circuit of the embodiment of the present invention also includes a resistor R10 and a resistor R11; wherein the resistor R10 is arranged between the output terminal of the voltage comparator U5.1 and the counter electrode (CE); one end of the resistor R11 is connected to the counter electrode, and the other end is grounded.

[0033] The voltage comparator U5.1, voltage follower U5.2 and digital-to-analog converter of the embodiment of the present invention all output scanning voltages. Since the non-inverting input terminal of the voltage comparator U5.1 is connected to the output terminal of the voltage reference U3, the scanning voltage range can be -REF2 to +(VREF2-VREF1).

[0034] The embodiment of the present invention uses the control voltage output by the digital-to-analog converter and the voltage output by the voltage reference U3 to apply a positive bias or a negative bias to the reference electrode and the counter electrode of the electrochemical sensor, thereby improving the flexibility of the portable electrochemical detection device of the present invention.

[0035] The current-to-voltage conversion circuit in the embodiment of the present invention is as follows Figure 4 As shown, including operational amplifier U5.3 (i.e. Figure 1 The transimpedance amplifier in the embodiment of the present invention comprises a resistor R12, a capacitor C12, a capacitor C13 and a voltage reference device U4; wherein the output end of the operational amplifier U5.3 is connected to the inverting input end of the operational amplifier U5.3 via the resistor R12 and the capacitor C13 arranged in parallel; the inverting input end of the operational amplifier U5.3 is also connected to the working electrode (WE) of the electrochemical sensor; the non-inverting input end of the operational amplifier U5.3 is ... Figure 5 The output of the voltage reference U4 is connected; the output of the operational amplifier U5.3 is connected to the low-pass filter circuit, and the output of the operational amplifier U5.3 is also grounded via capacitor C12. The non-inverting input of the operational amplifier U5.3 is connected to the output of the voltage reference U4, which can ensure that the working electrode is maintained at the reference potential of VREF1.

[0036] The low-pass filter circuit of the embodiment of the present invention is as follows Figure 6 As shown, it includes resistor R6, resistor R7, operational amplifier U5.4, capacitor C14 and capacitor C15. One end of resistor R6 is connected to the in-phase input terminal of operational amplifier U5.4, and the other end is connected to one end of resistor R7; the other end of resistor R7 is connected to the current-voltage conversion circuit, specifically, the other end of resistor R7 is connected to the output terminal of operational amplifier U5.3 in the current-voltage conversion circuit; one end of capacitor C14 is connected to the in-phase input terminal of operational amplifier U5.4, and the other end is grounded; the inverting input terminal of operational amplifier U5.4 is connected to the output terminal of operational amplifier U5.4, and the inverting input terminal of operational amplifier U5.4 is also connected to one end of capacitor C15; the other end of capacitor C15 is connected to resistor R6. The low-pass filter circuit of the embodiment of the present invention can effectively filter out high-frequency noise, and its cut-off frequency is .

[0037] The existing electrochemical circuit sampling is single-ended sampling, which is prone to deviation. In order to improve the accuracy of sampling and thus improve the accuracy of the electrochemical detection results, the present invention also provides an AD differential sampling circuit; the AD differential sampling circuit is connected to the low-pass filter circuit and the microprocessor respectively, and is used to convert the voltage signal output by the low-pass filter circuit into a digital signal and transmit it to the microprocessor. The AD differential sampling circuit of the embodiment of the present invention includes the following: Figure 7 The analog-to-digital converter, capacitor C9, resistors R13, R14, R15, R16, R17 and the like are shown in FIG. Figure 8The capacitors C10, C11 and resistors R18, R19 shown. Wherein the pin 9 of the analog-to-digital converter is connected to the voltage reference device U4 and grounded through the capacitor C9; resistors R13, R14, R15, R16, R17 are respectively connected to the pins 1, 2, 16, 15, 14 of the analog-to-digital converter, and the serial peripheral interface (SPI) completes data transmission with the microprocessor; one end of the resistor R18 is connected to the pin 11 of the analog-to-digital converter and grounded through the capacitor C10, and the other end is connected to the voltage reference device U4; one end of the resistor R19 is connected to the pin 10 of the analog-to-digital converter and grounded through the capacitor C11, and the other end is connected to the output end of the operational amplifier U5.4. The AD differential sampling circuit of the embodiment of the present invention obtains accurate digital signals through dual-channel differential sampling, and is transmitted to the microprocessor through the serial peripheral interface (SPI). Exemplarily, the model of the above-mentioned analog-to-digital converter is ADS1220IPWR, with a resolution of 24 bits, a sampling frequency of 2kHz, and a range of 0-2V. Use channel 0 and channel 1 of ADS1220IPWR to perform dual-channel differential acquisition and measurement data, where channel 0 is connected to the output of voltage reference U4 and channel 1 is connected to Figure 6 The output terminal AIN1 in.

[0038] In the embodiment of the present invention, the model of U5.1 to U5.4 may be RS8554XP, with an offset voltage of 1 μV and a noise of 0.75 uVp-p (0.01-10 Hz). The operational amplifier RS8554XP can reduce the drift current.

[0039] In order to obtain the concentration of the object to be tested intuitively and conveniently, the embodiment of the present invention also includes a mobile terminal connected to the microprocessor; the microprocessor sends a digital signal to the mobile terminal; the mobile terminal is used to convert the digital signal into the concentration information of the object to be tested and generate a real-time line chart for display. The mobile terminal can be a smart phone or tablet computer based on the Android system. The signal transmission between the microprocessor and the mobile terminal in the embodiment of the present invention is achieved through the low-power Bluetooth (BLE) built into the microprocessor.

[0040] The power supply circuit of the portable electrochemical detection device of the embodiment of the present invention is connected to the microprocessor. Exemplarily, the power supply circuit is a lithium battery power supply circuit, which is used to stabilize the lithium battery voltage to the working voltage required by the system, and includes a linear regulator (LDO), a capacitor C3 and a capacitor C4, such as Fig. 9As shown. Pins 1 and 3 of the linear regulator (LDO) are connected and connected to the positive electrode of the lithium battery; one end of the capacitor C3 is connected to pin 1 of the linear regulator (LDO), and the other end is grounded; one end of the capacitor C4 is connected to pin 5 of the linear regulator (LDO), and the other end is grounded. The linear regulator (LDO) model can be LD39015M33R, and the voltage difference is 100mV@(100mA).

[0041] The portable electrochemical detection device of the embodiment of the present invention can be connected to a soft-pack battery to supply power to various parts of the detection device.

[0042] The present invention discloses a portable electrochemical detection device with a wide range, adjustable and high precision, which can be applied to the detection of substances with trace concentrations. The detection process is to use an excitation circuit and a constant potential circuit to apply a positive bias or a negative bias to the electrochemical sensor. The current generated by the electrochemical sensor under the bias is converted into a voltage by a current-voltage conversion circuit and then enters a low-pass filter circuit to filter out high-frequency noise, and then an AD differential sampling circuit is used for dual-channel sampling, and then transmitted to a microcontroller through a serial peripheral interface (SPI), and finally the detection result is sent to a smart mobile terminal through a low-power Bluetooth (BLE), and a real-time line graph is generated. The present invention has the advantages of wide range, adjustable, high precision, high accuracy, small size, etc., and can meet the portable requirements. The present invention provides a new idea and method for the detection of trace harmful substances in the field of electrochemistry, and has broad application prospects in the fields of environmental monitoring, biomedicine, food safety, etc.

[0043] The above are only several embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, using the above disclosed technical content to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A portable electrochemical detection device, characterized in that: It includes an excitation circuit, a constant potential circuit, an electrochemical sensor, a current-voltage conversion circuit and a low-pass filter circuit connected in sequence; The excitation circuit is used to generate a control voltage; The constant potential circuit is used to apply a stable bias voltage to the reference electrode and the counter electrode of the electrochemical sensor in combination with the control voltage, so that a current signal corresponding to the concentration of the analyte is generated on the working electrode of the electrochemical sensor; The current-to-voltage conversion circuit is used to convert the current signal into a voltage signal; The low-pass filter circuit is used to filter out high-frequency noise in the voltage signal.

2. The portable electrochemical detection device according to claim 1, characterized in that: The excitation circuit includes a microprocessor and a digital-to-analog converter connected to the microprocessor; The microprocessor is used to receive an external control signal; The digital-to-analog converter is used to convert an external control signal into the control voltage.

3. The portable electrochemical detection device according to claim 2, characterized in that: The constant potential circuit includes a voltage reference U3, a negative feedback loop circuit and a voltage follower circuit; The voltage reference U3 is connected to the input end of the negative feedback loop circuit and the digital-to-analog converter respectively; the output end of the negative feedback loop circuit is connected to the pair of electrodes; The voltage follower circuit includes a voltage follower U5.2, a resistor R8 and a resistor R9; The non-inverting input terminal of the voltage follower U5.2 is connected to the reference electrode, and the output terminal and the inverting input terminal of the voltage follower U5.2 are both connected to one end of the resistor R9; the other end of the resistor R9 is connected to the negative feedback loop circuit; One end of the resistor R8 is connected to the digital-to-analog converter, and the other end is connected to the negative feedback loop circuit.

4. The portable electrochemical detection device according to claim 3, characterized in that: The negative feedback loop circuit includes a voltage comparator U5.1 and a capacitor C7; The inverting input terminal of the voltage comparator U5.1 is connected to the resistor R8, the non-inverting input terminal of the voltage comparator U5.1 is connected to the output terminal of the voltage reference U3, and the output terminal of the voltage comparator U5.1 is connected to the counter electrode; One end of the capacitor C7 is connected to the non-inverting input end of the voltage comparator U5.1, and the other end is connected to the output end of the voltage comparator U5.

1.

5. The portable electrochemical detection device according to claim 4, characterized in that: The negative feedback loop circuit also includes a resistor R10 and a resistor R11; The resistor R10 is arranged between the output end of the voltage comparator U5.1 and the pair of electrodes; One end of the resistor R11 is connected to the counter electrode, and the other end is grounded.

6. The portable electrochemical detection device according to claim 1, characterized in that: The current-to-voltage conversion circuit includes an operational amplifier U5.3, a resistor R12, a capacitor C12, a capacitor C13 and a voltage reference U4; The output end of the operational amplifier U5.3 is connected to the inverting input end of the operational amplifier U5.3 via a resistor R12 and a capacitor C13 arranged in parallel; the inverting input end of the operational amplifier U5.3 is also connected to the working electrode; The non-inverting input terminal of the operational amplifier U5.3 is connected to the voltage reference U4; the output terminal of the operational amplifier U5.3 is connected to the low-pass filter circuit, and the output terminal of the operational amplifier U5.3 is also grounded via the capacitor C12.

7. The portable electrochemical detection device according to claim 1, characterized in that: The low-pass filter circuit includes a resistor R6, a resistor R7, an operational amplifier U5.4, a capacitor C14 and a capacitor C15; One end of the resistor R6 is connected to the in-phase input end of the operational amplifier U5.4, and the other end is connected to one end of the resistor R7; the other end of the resistor R7 is connected to the current-voltage conversion circuit; One end of the capacitor C14 is connected to the in-phase input terminal of the operational amplifier U5.4, and the other end is grounded; The inverting input terminal of the operational amplifier U5.4 is connected to the output terminal of the operational amplifier U5.4, and the inverting input terminal of the operational amplifier U5.4 is also connected to one end of the capacitor C15; the other end of the capacitor C15 is connected to the resistor R6.

8. The portable electrochemical detection device according to claim 2, characterized in that: It also includes an AD differential sampling circuit; The AD differential adopting circuit is connected to the low-pass filtering circuit and the microprocessor respectively, and is used for converting the voltage signal output by the low-pass filtering circuit into a digital signal and transmitting it to the microprocessor.

9. The portable electrochemical detection device according to claim 8, characterized in that: Also included is a mobile terminal connected to the microprocessor; The microprocessor sends the digital signal to the mobile terminal; The mobile terminal is used to convert the digital signal into concentration information of the object to be tested and display the information.

10. The portable electrochemical detection device according to claim 2, characterized in that: It also includes a power supply circuit; the power supply circuit is connected to the microprocessor.

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