CN212622383U

CN212622383U - Dissolved oxygen detection device based on micro-fluidic chip

Info

Publication number: CN212622383U
Application number: CN202021820899.9U
Authority: CN
Inventors: 刘雨生; 徐佩锋; 孙健; 周李贤
Original assignee: Jiangsu Polytechnic College of Agriculture and Forestry
Current assignee: Jiangsu Polytechnic College of Agriculture and Forestry
Priority date: 2020-08-27
Filing date: 2020-08-27
Publication date: 2021-02-26
Anticipated expiration: 2030-08-27

Abstract

The utility model discloses a dissolved oxygen detection device based on micro-fluidic chip, including control circuit, detection circuitry, micro-fluidic chip sensor, wherein, the closed detection cavity of two-layer constitution about micro-fluidic chip sensor center is equipped with, is the oxygen permeable membrane of one deck between two-layer, and upper strata cavity side is equipped with the solution feed liquor pipe that awaits measuring, the solution drain pipe that awaits measuring of symmetry, is equipped with microelectrode and electrolyte feed liquor pipe, the electrolyte drain pipe that the cavity side was equipped with the symmetry in the cavity of lower floor, microelectrode and the detection circuitry connection of survey electric current size, this current signal feedback to control circuit for the concentration of oxygen in the calculation solution. The device detects the concentration of dissolved oxygen in the flowing state of the solution to be detected, thereby avoiding the operation that the traditional device needs to stir continuously; after the detection is finished, the electrolyte is automatically cleaned and periodically and automatically replaced, the detection precision is improved, and the method has a wide application prospect.

Description

Dissolved oxygen detection device based on micro-fluidic chip

Technical Field

The utility model relates to a dissolved oxygen's in the solution measurement especially relates to a dissolved oxygen detection device based on micro-fluidic chip.

Background

Dissolved oxygen is oxygen dissolved in water in a molecular state, is an indispensable condition for the survival of aquatic organisms, and is an important index for detecting biological activity and the degree of organic matter pollution of a water body. The currently used dissolved oxygen detection methods are four, namely an iodometry method, an amperometry method, a conductometry method and a fluorescence quenching method, wherein the amperometry method has the advantages of high measurement speed and simple operation and is widely applied, and most typical of the amperometry method is a sensor made of a clark dissolved oxygen electrode. However, because the oxygen permeable membrane and the electrode are easy to age, when a water sample contains algae, sulfide, carbonate, oil and other substances, the oxygen permeable membrane can be blocked or damaged, the cleaning and the protection need to be paid attention to, and because the oxygen concentration is determined by the redox reaction of the electrode under the action of oxygen, and oxygen is consumed in the determination process, the sample needs to be stirred ceaselessly in the measurement process, and the electrolyte needs to be replaced periodically, otherwise, the measurement precision and the response time of the electrolyte can be greatly influenced.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: the utility model aims at providing a dissolved oxygen detection device based on micro-fluidic chip realizes saving this operation of continuous stirring in the measurement process to the continuous detection of dissolved oxygen in the solution, and periodic replacement electrolyte and self-cleaning protect the oxygen permeation membrane, are convenient for maintain and use.

The technical scheme is as follows: the utility model provides a dissolved oxygen detection device based on micro-fluidic chip, including control circuit, detection circuitry, still include micro-fluidic chip sensor, micro-fluidic chip sensor center is equipped with the closed detection cavity of upper and lower two-layer constitution, be one deck oxygen permeation membrane between two-layer, upper strata cavity side is equipped with the solution feed liquor pipe that awaits measuring of symmetry, the solution drain pipe that awaits measuring, be equipped with the microelectrode in the cavity of lower floor and the cavity side is equipped with the electrolyte feed liquor pipe of symmetry, the electrolyte drain pipe, the microelectrode is connected with the detection circuitry of survey electric current size, this current signal feedback to control circuit for the concentration of oxygen in the calculation solution.

The liquid inlet pipe and the liquid outlet pipe of the solution to be measured of the upper cavity and the liquid inlet pipe and the liquid outlet pipe of the electrolyte of the lower cavity are arranged in an X-shaped cross mode.

Preferably, the oxygen permeable membrane is a polyethylene and polytetrafluoroethylene film having a thickness of 25-50 μm.

Preferably, the microelectrodes are polarographic electrodes, the anode electrode is Ag/AgCl, and the cathode electrode is Pt.

Preferably, the control circuit adopts an ARM chip, the chip puts acquired data into a designated register, and controls the cleaning and liquid changing module to clean the microfluidic chip after the detection operation is finished, and the liquid changing operation is performed when the electrolyte is insufficient.

The cleaning and liquid changing module comprises a micro-water pump, a flowmeter, a thin tube, a cleaning liquid box and an electrolyte box, wherein the thin tube is used for connecting the micro-fluidic chip sensor, the micro-water pump, the flowmeter, a cleaning liquid and electrolyte. When the detection operation is carried out, the cleaning operation and the liquid changing operation are not carried out, the control circuit controls the micro water pump, the water pump provides power to introduce the liquid to be detected into the micro-fluidic chip for detection, after the detection operation is finished, the cleaning operation is carried out, the water pump provides power to introduce the cleaning liquid into the micro-fluidic chip detection micro-chamber, and the micro-chamber is cleaned. The electrolyte is periodically changed, the control chip controls the water pump to be periodically powered by the water pump, and the electrolyte is introduced to perform liquid supplementing and changing operations.

Meanwhile, the display module is connected with the control circuit and used for displaying the concentration of oxygen in the solution in real time.

When the detection is started, the control circuit receives a signal for starting the detection, controls the micro water pump to slowly feed in the liquid to be detected, then collects data of the detection circuit in real time, displays the data through the display module, controls the cleaning and liquid changing module to clean after the detection is finished, and regularly changes the electrolyte.

Has the advantages that: compared with the prior art, the utility model has the obvious advantages that the micro-detection based on the micro-fluidic chip avoids consuming excessive samples, automatically leads in the flowing liquid to be detected, and avoids the operation of continuous stirring; the automatic cleaning is carried out after the detection is finished, so that manual cleaning in the traditional technology is omitted, and manpower and material resources are saved; electrolyte is replaced automatically at regular intervals, and detection precision is improved.

Drawings

Fig. 1 is a front view of a microfluidic chip sensor according to the present invention;

fig. 2 is a top view of the microfluidic chip sensor of the present invention;

fig. 3 is a schematic flow chart of the present invention.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1 and 2, the center of the microfluidic chip sensor is provided with a closed detection cavity formed by an upper layer and a lower layer, an upper layer cavity 1 and a lower layer cavity 2 are provided with an oxygen permeable membrane 3 therebetween, the side edge of the upper layer cavity 1 is provided with a symmetrical solution inlet pipe 11 and inlet 12 to be detected, a symmetrical solution outlet pipe 13 and outlet 14 to be detected, the lower layer cavity 2 is provided with a microelectrode 4, the side edge of the cavity is provided with a symmetrical electrolyte inlet pipe 21 and inlet 22, and an electrolyte outlet pipe 23 and outlet 24, and the solution inlet pipe 11 and the solution outlet pipe 13 to be detected of the upper layer cavity 1 and the electrolyte inlet pipe 21 and the electrolyte outlet pipe 23 of the lower layer cavity 2 are arranged in an X-shaped.

As shown in fig. 3, a dissolved oxygen detection device based on a microfluidic chip comprises a microfluidic chip sensor, a detection circuit, a cleaning and liquid changing module, a control circuit, a display module, and a power supply module. The micro-fluidic chip sensor is a dissolved oxygen sensor and is used for detecting the content of dissolved oxygen and converting the content of dissolved oxygen in a solution into a current signal, the detection circuit is a signal conditioning circuit and realizes the amplification, isolation and filtering operation of weak electric signals, and the cleaning and liquid changing module comprises a micro water pump, a flowmeter, a thin tube, a cleaning liquid box and an electrolyte box and is used for cleaning the sensor after the detection operation and supplementing electrolyte. The control circuit is used for collecting, analyzing and calculating data and controlling the cleaning and liquid changing module to perform cleaning and liquid changing operations, and the display module is used for storing the data collected by the control circuit and displaying a dissolved oxygen detection result. The power module is used for supplying power to the device.

Detection operation: when the detection is started, the control circuit controls the micro water pump to feed a solution to be detected into the upper cavity of the micro-fluidic chip sensor, the solution to be detected is fed from the inlet 12 of the upper cavity, the outlet 14 is connected with the micro water pump to slowly pump the solution to be detected, the solution passes through the liquid inlet pipe 11, enters the upper cavity 1, and is sucked out from the outlet 14 through the liquid outlet pipe 13. When a solution to be measured enters the upper-layer cavity 1, oxygen in the solution permeates into electrolyte in the lower-layer cavity 2 through the oxygen permeable membrane 3, an oxidation-reduction reaction immediately occurs on the microelectrode 4, current generated by the reaction is in direct proportion to the concentration of the oxygen, a current signal generated by the reaction is processed by the detection circuit and then is returned to the control circuit for calculation and analysis, and finally measured data can be displayed on the display screen.

And (3) cleaning operation: after the measurement operation is finished, the control circuit controls the micro water pump to feed cleaning liquid into the upper cavity 1 in the micro-fluidic chip sensor, the cleaning liquid is fed from an inlet 12 of the upper cavity 1, an outlet 14 is connected with the micro water pump to extract the cleaning liquid, the cleaning liquid is enabled to pass through a liquid inlet pipe 11 and enter the upper cavity 1, then the cleaning liquid is sucked out from the outlet 14 through a liquid outlet pipe 13, and the cleaning liquid is rapidly fed into the upper cavity 1 to achieve the cleaning effect on the upper cavity 1.

Liquid changing operation: the control circuit controls the micro water pump to feed electrolyte into the lower cavity 2 of the micro-fluidic chip sensor, the electrolyte is fed from an inlet 22 of the lower cavity 2, an outlet 24 is connected with the micro water pump to extract the electrolyte, the electrolyte passes through the liquid inlet pipe 21 and enters the lower cavity 2, and then the electrolyte is sucked out from the outlet 24 through the liquid outlet pipe 23, so that the electrolyte replacement of the lower cavity 2 of the micro-fluidic chip sensor is completed.

In the detection operation, the liquid to be detected is automatically introduced, and the operation that the traditional device needs to be stirred continuously is avoided through flow monitoring; the control circuit collects data of the detection circuit in real time and displays the data through the display module; after the detection is finished, the control circuit controls the cleaning and liquid changing module to clean without manual cleaning, and electrolyte is periodically changed, so that the inaccurate detection result caused by insufficient electrolyte is avoided.

Claims

1. The utility model provides a dissolved oxygen detection device based on micro-fluidic chip, includes control circuit, detection circuitry, its characterized in that still includes the micro-fluidic chip sensor, the closed detection cavity that two-layer constitutes about micro-fluidic chip sensor center is equipped with, is one deck oxygen permeable membrane (3) between two-layer, and upper cavity (1) side is equipped with the solution feed liquor pipe (11) that awaits measuring, the solution drain pipe (13) that awaits measuring of symmetry, is equipped with microelectrode (4) and electrolyte feed liquor pipe (21), electrolyte drain pipe (23) that the cavity side was equipped with the symmetry in lower floor cavity (2), microelectrode (4) are connected with the detection circuitry of survey electric current size, and this current signal feeds back to control circuit for the concentration of oxygen in the calculation solution.

2. The dissolved oxygen detection device based on the microfluidic chip according to claim 1, wherein the solution inlet pipe (11) and the solution outlet pipe (13) to be detected of the upper cavity (1) and the electrolyte inlet pipe (21) and the electrolyte outlet pipe (23) of the lower cavity (2) are arranged in an X-shaped cross manner.

3. The dissolved oxygen detection device based on the microfluidic chip as claimed in claim 1, wherein the oxygen permeable membrane (3) is a polyethylene and polytetrafluoroethylene film with a thickness of 25-50 μm.

4. The dissolved oxygen detection device based on the microfluidic chip as claimed in claim 1, wherein the micro-electrode (4) is a polarographic electrode, the anode electrode is Ag/AgCl, and the cathode electrode is Pt.

5. The microfluidic chip based dissolved oxygen detection device according to claim 1, wherein the control circuit is an ARM chip.

6. The dissolved oxygen detection device based on the microfluidic chip according to claim 1, further comprising a cleaning and liquid changing module including a micro water pump, a flow meter, a tubule, a cleaning liquid box, and an electrolyte box, wherein the tubule connects the microfluidic chip sensor, the micro water pump, the flow meter, the cleaning liquid box, and the electrolyte box, and the micro water pump is controlled by the control circuit.

7. The dissolved oxygen detection device based on the microfluidic chip according to claim 1, further comprising a display module, wherein the display module is connected with the control circuit and is used for displaying the concentration of oxygen in the solution in real time.