CN111090002A - Nanopore gene sequencing micro-current detection device and current stability compensation method - Google Patents

Abstract

The invention provides a nanopore gene sequencing micro-current detection device, which comprises a detection circuit for detecting current change generated when DNA molecules flow through a nanopore on a thin film, wherein the detection circuit comprises a first electrode, a second electrode, a third electrode and a constant potential circuit; when the working electrode deflects, the constant potential circuit makes the ground potential of the counter electrode pair always follow the ground potential of the reference electrode pair, so that a stable voltage difference is kept between the first electrode and the second electrode. The invention also relates to a compensation method for the stability of the micro-current in the nanopore gene sequencing. The invention changes the current signal detected by the working electrode into a voltage signal through the integral amplifier, the integral amplifier takes a capacitor as a feedback element, and two sampling and holding circuits are adopted to realize related double sampling, thereby having lower noise performance, improving the bandwidth and the linearity of the signal, simultaneously carrying out filtering, denoising, compensation and other processing on the current signal, and greatly improving the accuracy of current detection.

Description

Nanopore gene sequencing microcurrent detection device and compensation method for current stabilization

technical field

The invention relates to the technical field of electronics, in particular to a nanopore gene sequencing microcurrent detection device.

Background technique

The third-generation nanopore gene sequencing technology, characterized by single-molecule and sequencing-by-synthesis, has significant advantages in read length, cost, and speed, and is one of the current research hotspots. The principle of nanopore sequencing is to detect the weak characteristic current changes generated when the unwound DNA single strand passes through the nanopore to determine its base sequence. Therefore, accurate measurement of this characteristic current is one of the key technologies to achieve high-accuracy gene sequencing. Currently, a two-electrode electrochemical system is widely used in nanopore gene sequencing. A certain voltage is applied between the two electrodes to drive DNA through the nanopore. However, due to the existence of the Faraday process, the voltage difference between the two electrodes is very easy to fluctuate, resulting in potential offset, and because the current is extremely weak, generally in the picoamp level, the change in the voltage difference will greatly affect the detection accuracy of the current. , affecting the accuracy of sequencing.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the prior art, the present invention provides a nanopore gene sequencing microcurrent detection device.

The present invention solves the above technical problem by adding a third electrode between the first electrode and the second electrode, and the third electrode forms a constant potential between the first electrode and the second electrode.

The invention provides a nanopore gene sequencing microcurrent detection device, which includes a detection circuit for the current change that occurs when DNA molecules flow through a nanopore channel on a thin film, and is characterized in that the detection circuit includes a first electrode, a second electrode, a Three electrodes and a potentiostatic circuit, the first electrode and the second electrode are arranged on both sides of the film, and a voltage is applied between the first electrode and the second electrode to drive the DNA single strand on the film to pass through the nanometer a pore channel, the second electrode is used to detect the current signal generated when the DNA molecule passes through the nanopore channel;

The third electrode is arranged between the first electrode and the second electrode, the third electrode is connected to the constant potential circuit, and the constant potential circuit is connected to the first electrode; the constant potential circuit adjusts the The potential of the first electrode to the ground always follows the change of the potential of the third electrode to the ground, so that a stable voltage difference is maintained between the first electrode and the second electrode.

Preferably, the potentiostatic circuit comprises a potentiostat and a data processing component, the potentiostat is connected to the first electrode, and the data processing component is located between the potentiostat and the second electrode ; The data processing component sends an instruction for configuring the potentiostat generator according to the detected potential offset of the second electrode, so that a constant potential is formed between the first electrode and the second electrode.

Preferably, an integrating amplifier is included between the second electrode and the data processing component, and the integrating amplifier is used to convert the current signal detected by the second electrode into a voltage signal; wherein, the integrating amplifier adopts a high input stage impedance.

Preferably, at least one sample-and-hold device is included between the integrating amplifier and the data processing component, and the sample-and-hold device is used to hold the sampled value.

Preferably, the potential of the second electrode to ground is zero.

Preferably, the potentiostatic generator includes an operational amplifier for supplying current to the first electrode, and an inverting input of the operational amplifier is connected to the third electrode.

Preferably, the constant potential generator further comprises a bias voltage source, the bias voltage source is electrically connected to the data processing component, the data processing component sends an instruction to the bias voltage source, and the bias voltage source is used for setting A constant potential between the first electrode and the second electrode is determined.

The present invention also provides a compensation method for micro-current stabilization of nanopore gene sequencing, wherein high-frequency compensation is performed on the amplified output signal of the integrating amplifier, and the high-frequency compensation is used to attenuate the output signal amplified by the integrating amplifier. High frequency components of the output signal.

Preferably, the zero-point overshoot compensation is performed by a low-pass filter before the high-frequency compensation is performed; the offset voltage post-compensation is added while the zero-point overshoot compensation is performed, and the bias voltage post-compensation is used to eliminate all The bias voltage output from the integrating amplifier.

Preferably, compensation for electrode capacitance, membrane capacitance and nanopore series resistance is also included; wherein,

The compensation for the electrode capacitance and the membrane capacitance includes connecting a first compensation branch and a second compensation branch at the inverting input end of the integrating amplifier, respectively, and the first compensation branch and the second compensation branch are respectively used for the The electrode capacitance and the membrane capacitance provide current; the first compensation branch and the second compensation branch are connected with a step voltage at the same time, and the step voltage makes the first compensation branch and the electrode capacitance and the electrode capacitance pass through. The current of the second compensation branch and the membrane capacitor are equal in magnitude and opposite in direction;

The compensation for the series resistance of the nanopores includes taking out a certain proportion of the output voltage of the integrating amplifier, which is used to offset the voltage drop caused by the series resistance of the nanopores, and form a compensation circuit for correcting the loop.

Compared with the prior art, the beneficial effects of the present invention are:

The invention discloses a nanopore gene sequencing microcurrent detection device. The device comprises a counter electrode and a working electrode arranged on both sides of a lipid membrane, a reference electrode is arranged between the counter electrode and the working electrode, and the working electrode and the reference electrode are arranged between the working electrode and the reference electrode. The bias voltage is applied through the constant potential generator. When the working electrode is offset, the constant potential generator makes the potential of the counter electrode to the ground always follow the change of the potential of the reference electrode to the ground, so as to ensure a constant formation between the counter electrode and the working electrode. The electrical potential is used to drive DNA molecules through the nanopore. In addition, the current signal detected by the working electrode is changed into a voltage signal through the integrating amplifier. The integrating amplifier uses the capacitor as the feedback element, and uses two sample-and-hold circuits to achieve correlated double sampling, which has lower noise performance and improves the signal quality. At the same time, the current signal is also processed by filtering, denoising, compensation, etc., which greatly improves the accuracy of current detection.

The invention also discloses a compensation method for microcurrent stabilization of nanopore gene sequencing, which can accurately and stably detect the current signal fluctuation of picoamp level generated when DNA molecules pass through the nanopore, and the detection accuracy can be as low as 10 Below picoam, high-accuracy nanopore gene sequencing can be achieved.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, and implement it according to the content of the description, the preferred embodiments of the present invention are described in detail below with the accompanying drawings. Specific embodiments of the present invention are given in detail by the following examples and the accompanying drawings.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Fig. 1 is the overall structure diagram of the nanopore gene sequencing microcurrent detection device of the present invention;

2 is a specific structural diagram of the nanopore gene sequencing microcurrent detection device of the present invention;

3 is a structural diagram of a potentiostatic generator of the nanopore gene sequencing microcurrent detection device of the present invention;

4 is a schematic diagram of a compensation method for nanopore gene sequencing microcurrent stabilization according to the present invention;

Reference numerals: 10, lipid membrane, 20, DNA molecule, 30, nanopore, 40, second electrode, 50, first electrode, 60, third electrode, 70, potentiostatic circuit, 710, potentiostatic generator , 720, integrating amplifier, 730, denoising unit, 740, first sample-and-hold, 750, second sample-and-hold, 760, data processing component, 711, first capacitor, 712, first resistor, 713, second Resistor, 714, Second Capacitor, 715, Operational Amplifier, 716, Bias Voltage Source, 800, Boost Overshoot Circuit, 810, High Frequency Compensation, 820, Zero Overshoot Compensation, 830, Offset Compensation, 840, Bias Voltage Post-compensation, 850, low-pass filter, 860, first compensation branch, 870, step voltage, 880, second compensation branch, 890, compensation circuit of the correction loop.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that, on the premise of no conflict, the embodiments or technical features described below can be combined arbitrarily to form new embodiments. .

The present invention provides a nanopore gene sequencing microcurrent detection device, as shown in Figures 1-3, comprising a detection circuit for the current change that occurs when a DNA molecule flows through a nanopore channel on a thin film, the detection circuit includes a first electrode 50, The second electrode 40, the third electrode 60 and the potentiostatic circuit 70, the first electrode 50 and the second electrode 40 are arranged on both sides of the film, and a voltage is applied between the first electrode 50 and the second electrode 40 to The DNA single strand on the film is driven to pass through the nanopore channel 30, and the second electrode 40 is used to detect the current signal generated when the DNA molecule 20 passes through the nanopore channel 30;

The third electrode 60 is disposed between the first electrode 50 and the second electrode 40 , the third electrode 60 is connected to the constant potential circuit 70 , and the constant potential circuit 70 is connected to the first electrode 50 ; The potentiostatic circuit 70 adjusts the potential of the first electrode 50 to the ground to always follow the change of the potential of the third electrode 60 to the ground, so as to maintain a stable voltage difference between the first electrode 50 and the second electrode 40 . In one embodiment, a certain voltage is applied between the first electrode 50 and the second electrode 40 for driving the DNA molecules 20 to pass through the nanopore 30, the first electrode 50 is a counter electrode, and the second electrode 40 is a working electrode , the working electrode is used to detect the weak current signal generated when the DNA molecule 20 passes through the nanopore 30 . A reference electrode is arranged between the counter electrode and the working electrode, and the reference electrode is connected to a potentiostatic circuit 70. The potentiostatic circuit 70 makes the potential of the counter electrode to the ground always follow the change of the potential of the reference electrode to the ground, so as to ensure that the counter electrode and the work A constant potential is formed between the electrodes for driving the DNA molecules 20 through the nanopore channel 30 .

The potentiostatic circuit 70 includes a potentiostatic generator 710 and a data processing component 760, the potentiostatic generator 710 is connected to the first electrode 50, and the data processing component 760 is located between the potentiostatic generator 710 and the first electrode 50. Between the two electrodes 40; the data processing component 760 will send an instruction according to the detected potential offset of the second electrode 40 for configuring the potentiostat generator 710, so that the first electrode 50 and the A constant potential is formed between the second electrodes 40 . In one embodiment, the film is preferably the lipid membrane 10, the nanopores 30 are embedded between the bilayer lipid membranes 10, the nanopores 30 connect the upper and lower regions of the lipid membrane 10, and the potentiostatic generator 710 is used for A bias voltage is formed between the working electrode and the counter electrode in the three-electrode system to drive the DNA molecules 20 to pass through the nanopore 30, and an ionic current is formed at the same time, and the potential of the counter electrode to the ground always follows the change of the potential of the reference electrode; 710 is used to maintain a stable and constant driving voltage between the working electrode and the counter electrode.

In one embodiment, the second electrode 40, that is, the working electrode has zero potential to ground, and the working electrode has zero potential to ground to achieve a stable and controllable driving voltage between the reference electrode and the working electrode, and the current is only Between the electrode and the working electrode, no current flows through the reference electrode to avoid polarization.

An integrating amplifier 720 is included between the second electrode 40 and the data processing component 760, and the integrating amplifier 720 is used to convert the current signal detected by the second electrode 40 into a voltage signal; wherein, the integrating amplifier 720 adopts High input stage impedance. In one embodiment, the integrating amplifier 720 is used to convert the detected current signal into a voltage signal. The integrating amplifier 720 adopts a high input stage impedance and uses a small capacitor as a feedback element to form an integrating circuit, but since the capacitor needs to be periodically discharged, A switch needs to be placed in parallel with the capacitor to control the charging and discharging process of the capacitor. The integrating amplifier 720 is connected with a de-noising unit 730, and the de-noising unit 730 is configured to perform de-noising processing on the noise generated in the current signal detection process.

At least one sample-and-hold is included between the integrating amplifier 720 and the data processing component 760, and the sample-and-hold is used to hold the sampled value. In one embodiment, in order to prevent the integrating amplifier 720 from being unable to process the signal in the feedback capacitor discharge device, a sample-and-hold device is configured to hold the sampled value, and the sample-and-hold device adopts the correlated double sampling technology. The sample-and-hold device includes the first sample-and-hold device 740 and the The second sample-and-hold 750, the first sample-and-hold 740 is connected in parallel with the second sample-and-hold 750, and the accuracy of current signal detection is improved while reducing noise, which is generally composed of an analog switch, a storage capacitor and a buffer amplifier, and It is controlled by the analog switch whether it belongs to the sampling state or the holding state.

The potentiostat generator 710 includes an operational amplifier 715 for supplying current to the first electrode 50 , and an inverting input of the operational amplifier 715 is connected to the third electrode 60 . The constant potential generator 710 further includes a bias voltage source 716, the bias voltage 716 is electrically connected to the data processing component 760, and the data processing component 760 sends an instruction to the bias voltage source 716, the bias voltage The source 716 is used to set a constant potential between the first electrode 50 and the second electrode 40 . In one embodiment, the operational amplifier 715 supplies current to the counter electrode to balance the current required by the working electrode, and the inverting input is connected to the reference electrode, the operational amplifier 715 maintains the working and counter electrodes at a constant potential, which is determined by Bias voltage source 716 is provided, and bias voltage source 716 is controlled by data processing component 760 . Since the current on the reference electrode is extremely small, any offset caused by the input offset voltage in the operational amplifier 715 will cause a sudden change in the turn-on potential. The selected operational amplifier 715 should ensure that the input bias current is small The low offset voltage is typically less than 100 μV and controls the op amp 715 to operate at a constant temperature. The circuit stability and noise reduction of the potentiostatic circuit 70 depend on resistance and capacitance. The resistance includes a first resistance 712 and a second resistance 713 , and the capacitance includes a first capacitance 711 and a second capacitance 714 , as shown in FIG. 3 .

In addition, the data processing group, 760 is also used to convert the voltage signal into a digital signal, which is generally composed of a single-chip microcomputer, an FPGA (field programmable gate array) processor, an analog-to-digital conversion function module, and a data transmission module to transmit data to the upper level. Large-scale data analysis is carried out by computer and computer, so as to realize the base sequence identification and assembly of DNA molecules.

The present invention also provides a compensation method for nanopore gene sequencing microcurrent stabilization, as shown in FIG. 4 , which includes performing high-frequency compensation 810 on the amplified output signal of the integrating amplifier 720, and the high-frequency compensation 810 is used to weaken the The high frequency components of the output signal after being amplified by the integrating amplifier 720 . Before performing the high-frequency compensation 810, a low-pass filter is used to perform zero-point overshoot compensation 820; while performing the zero-point overshoot compensation 820, a bias voltage post-compensation 840 is added, and the bias voltage post-compensation 840 is used for The offset voltage output in the integrating amplifier 720 is eliminated. In one embodiment, in order to solve the problem that the high frequency component of the output signal amplified by the integrating amplifier 720 is weakened, a high frequency compensation 810 is performed on the circuit to provide a bandwidth, and the zero point of the integrating amplifier 720 will compensate the output signal of the high frequency 810 at the same time. An overshoot phenomenon occurs, so before the high frequency compensation 810 , a low-pass filter is used to perform zero-point overshoot compensation 820 . In addition, there is a certain output bias voltage in the integrating amplifier 720, which needs to be zero-adjusted internally or externally, that is, the input offset compensation of the integrating amplifier 830, the offset voltage is added to the zero-point overshoot compensation 820 and the offset voltage is added to compensate 840, so as to Eliminate the negative effects of bias voltage.

In the process of nanopore gene sequencing detection, DNA single molecule passing through the nanopore channel will generate via noise. The frequency range of DNA single molecule perforation ion current signal and the frequency range of noise and interference signals will overlap, and the frequency of noise is usually higher than that of detection. The frequency of the signal is large, and noise and interference signals are filtered out by the low-pass filter 850 , and the frequency of the low-pass filter 850 is preferably 10 kHz.

Also includes compensation for electrode capacitance, membrane capacitance, and nanopore series resistance; where,

Compensation for the electrode capacitance and membrane capacitance includes connecting a first compensation branch 860 and a second compensation branch 880 at the inverting input end of the integrating amplifier 720 respectively, and the first compensation branch 860 and the second compensation The branches 880 are respectively used to supply current to the electrode capacitance and the membrane capacitance; the first compensation branch 860 and the second compensation branch 880 are connected to a step voltage 870 at the same time, and the step voltage 870 makes the step voltage 870 pass through the The currents of the first compensation branch 860 and the electrode capacitor and the second compensation branch 880 and the membrane capacitor are equal in magnitude and opposite in direction;

The compensation for the series resistance of the nanopores includes taking a certain proportion of the output voltage of the integrating amplifier 720 to cancel the voltage drop caused by the series resistance of the nanopores, and to form a compensation circuit 890 for a correction loop.

The electrode capacitance is not purely capacitive, and there are resistances in series with it, such as electrode resistance and the resistance of the electrolyte solution and the liquid in the electrode. The influence of the electrode capacitance on the circuit is mainly when the detection system starts to operate. This is because the time constant of the electrode capacitance is relatively small, at the uS level. The signal is 2 to 3 orders of magnitude higher, which is enough to overwhelm the detection signal and make the amplifier enter the saturation region, seriously affecting the operation of the detection system. An electrode capacitance compensation branch, namely the first compensation branch 860, is connected to the inverting input end of the integrating amplifier 720 to provide current for charging and discharging the electrode capacitance. A synchronous step voltage 870 is also input to the other end of the capacitor, so that the current passing through the compensation capacitor is exactly equal in magnitude and opposite in direction to the charging and discharging current of the electrode capacitor to be eliminated. At the same time, due to the existence of the electrode capacitance time constant, the step voltage signal applied to the compensation capacitor branch also needs to be output through a delay circuit with an adjustable time constant, so that the compensation current and the electrode capacitance current are better matched. .

The time constant of the membrane capacitance is higher than that of the electrode capacitance, which is tens to hundreds of uS. Compensation is similar to electrode capacitance compensation, so that the voltage source step voltage 870 of the membrane capacitance compensation path, that is, the second compensation branch 880, passes through the time delay circuit and the proportional adjustment circuit and is output to the compensation capacitor.

The series resistance of nanopores has two main hazards to the measurement circuit: one is that it limits the charging and discharging time of the membrane capacitance, which affects the index of rapid DNA measurement and makes the system bandwidth not as high as expected, which has been partially affected by the previous membrane capacitance. The compensation path is used to make up for it; there is also a voltage drop caused by the current flowing through the series resistance. For the detection current part, a compensation channel is applied to the output of the integrating amplifier, and the output voltage of the integrating amplifier proportional to the detection current is taken out. A certain proportion, The compensation circuit 890 used to offset part of the voltage drop to form a correction loop can improve the time resolution of the detection current signal, and the system bandwidth capability will also be improved; for the charge and discharge current part of the film capacitor, when the driving voltage is applied, the The leading edge and trailing edge of the pulse each add a short charge or discharge pulse, so that the change of the membrane voltage starts to change to a level higher or lower than the preset voltage value, and the additional pulse is immediately removed once the preset value is reached, Obviously, the change speed of the membrane voltage is improved, and such a booster overshoot circuit can predict and compensate the voltage drop of the charging and discharging current of the membrane capacitor across the series resistance at each moment. Since the primary factor affecting the weak current measurement sensitivity is the bias current of the integrating amplifier 720 and its drift with temperature or time, the pre-integrating amplifier should satisfy that the bias current is as small as possible less than the weak current to be measured, and the gain, High common mode rejection ratio, small offset voltage and drift, and low noise are required. JFET devices with low noise, high gain and low bias current such as AD549L can be selected.

The invention discloses a nanopore gene sequencing microcurrent detection device, which comprises a counter electrode and a working electrode arranged on both sides of a lipid membrane 10, a reference electrode is arranged between the counter electrode and the working electrode, and the working electrode and the reference electrode are arranged between the counter electrode and the working electrode. A bias voltage is applied between the specific electrodes through the potentiostat generator 710. When the working electrode is offset, the potentiostat generator 710 makes the potential of the counter electrode to the ground always follow the change of the potential of the reference electrode to the ground, so as to ensure that the counter electrode and the working electrode change. A constant potential is formed therebetween for driving the DNA molecules 20 through the nanopore channel 30 . In addition, the current signal detected by the working electrode is changed into a voltage signal through the integrating amplifier 720. The integrating amplifier 720 uses the capacitor as the feedback element, and uses two sample-and-hold circuits to achieve correlated double sampling, which has lower noise performance and improved performance. The bandwidth and linearity of the signal, and at the same time, the current signal is also processed by filtering, denoising, compensation, etc., which greatly improves the accuracy of current detection.

The invention also discloses a compensation method for microcurrent stabilization of nanopore gene sequencing, which can accurately and stably detect the current signal fluctuation of picoamp level generated when DNA molecules pass through the nanopore, and the detection accuracy can be as low as 10 Below picoam, high-accuracy nanopore gene sequencing can be achieved.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form; any person of ordinary skill in the industry can smoothly implement the present invention as shown in the accompanying drawings and above; however, any Those skilled in the art, without departing from the scope of the technical solution of the present invention, make use of the above-disclosed technical content to make some changes, modifications and equivalent changes of evolution are equivalent embodiments of the present invention; at the same time, Any alteration, modification and evolution of any equivalent changes made to the above embodiments according to the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. Nanopore gene sequencing microcurrent detection device, comprising the detection circuit of the current change that occurs when DNA molecules flow through the nanopore channel on the film, it is characterized in that, the detection circuit comprises a first electrode, a second electrode, a third Electrodes and a potentiostatic circuit, the first electrode and the second electrode are arranged on both sides of the film, and a voltage is applied between the first electrode and the second electrode to drive the DNA single strand on the film to pass through the nanopore , the second electrode is used to detect the current signal generated when the DNA molecule passes through the nanopore; The third electrode is arranged between the first electrode and the second electrode, the third electrode is connected to the constant potential circuit, and the constant potential circuit is connected to the first electrode; the constant potential circuit adjusts the The potential of the first electrode to the ground always follows the change of the potential of the third electrode to the ground, so that a stable voltage difference is maintained between the first electrode and the second electrode. 2. The nanopore gene sequencing microcurrent detection device of claim 1, wherein the potentiostatic circuit comprises a potentiostatic generator and a data processing assembly, and the potentiostatic generator is connected to the first electrode , the data processing component is located between the potentiostatic generator and the second electrode; the data processing component will send an instruction for configuring the potentiostatic generation according to the detected potential offset of the second electrode so that a constant potential is formed between the first electrode and the second electrode. 3 . The nanopore gene sequencing microcurrent detection device according to claim 2 , wherein an integrating amplifier is included between the second electrode and the data processing component, and the integrating amplifier is used to detect the second electrode. 4 . The resulting current signal is converted into a voltage signal; wherein, the integrating amplifier adopts a high input stage impedance. 4 . The nanopore gene sequencing microcurrent detection device according to claim 3 , wherein at least one sample holder is included between the integrating amplifier and the data processing component, and the sample holder is used to hold the sampled value. 5 . . 5 . The nanopore gene sequencing microcurrent detection device of claim 1 , wherein the second electrode has zero potential to ground. 6 . 6 . The nanopore gene sequencing microcurrent detection device of claim 2 , wherein the potentiostatic generator comprises an operational amplifier, and the operational amplifier is used to supply current to the first electrode, and the operational amplifier The inverting input of the amplifier is connected to the third electrode. 7 . The nanopore gene sequencing microcurrent detection device according to claim 6 , wherein the potentiostatic generator further comprises a bias voltage source, the bias voltage source is electrically connected to the data processing component, and the data The processing component sends an instruction to the bias voltage source for setting a constant potential between the first electrode and the second electrode. 8. A compensation method for microcurrent stabilization of nanopore gene sequencing, characterized in that it comprises performing high-frequency compensation on the amplified output signal of the integrating amplifier, and the high-frequency compensation is used to weaken the output signal amplified by the integrating amplifier. the high frequency components of the output signal. 9 . The compensation method for nanopore gene sequencing microcurrent stability according to claim 8 , wherein, before the high-frequency compensation is performed, a low-pass filter is used to perform zero-point overshoot compensation; The offset voltage post-compensation is added during the compensation, and the offset voltage post-compensation is used to eliminate the offset voltage output in the integrating amplifier. 10. The method for compensating nanopore gene sequencing microcurrent stability according to claim 8, further comprising compensation for electrode capacitance, membrane capacitance and nanopore series resistance; wherein, The compensation for the electrode capacitance and the membrane capacitance includes connecting a first compensation branch and a second compensation branch at the inverting input end of the integrating amplifier respectively, and the first compensation branch and the second compensation branch are respectively used for the compensation. In order to provide current to the electrode capacitance and the membrane capacitance; the first compensation branch and the second compensation branch are connected with a step voltage at the same time, and the step voltage makes the first compensation branch and the electrode pass through. The current of the capacitor and the second compensation branch and the membrane capacitor are equal in magnitude and opposite in direction; The compensation for the series resistance of the nanopores includes taking out a certain proportion of the output voltage of the integrating amplifier, which is used to offset the voltage drop caused by the series resistance of the nanopores, and form a compensation circuit for correcting the loop.

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