阅读说明：本技术 微流控芯片及其体系、水体中重金属离子的检测方法 (Micro-fluidic chip and system thereof, and detection method of heavy metal ions in water body ) 是由 廖晓玲 徐文峰 黄秋红 张泽霖 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种微流控芯片,其包括芯片本体,以及设置在该芯片本体内的至少一个检测功能单元,该检测功能单元包括进样口、预处理子单元、反应检测子单元,以及试剂进样子单元,从而使得可通过进样口加入石油废水等待检测样品,使其经预处理子单元进行预处理后,进入反应检测子单元与经试剂进样子单元加入后流入该反应检测子单元内的检测试剂进行反应,以实现对待检测样品的快速检测,且该微流控芯片便于携带,无也需大型检测分析设备,降低了检测成本。相应地,本发明还提供了一种微流控芯片体系,以及水体中重金属离子的检测方法。(The invention discloses a micro-fluidic chip, which comprises a chip body and at least one detection functional unit arranged in the chip body, wherein the detection functional unit comprises a sample inlet, a pretreatment subunit, a reaction detection subunit and a reagent sample inlet subunit, so that petroleum wastewater can be added through the sample inlet to wait for a detection sample, the petroleum wastewater enters the reaction detection subunit to react with a detection reagent which flows into the reaction detection subunit after being added through the reagent sample inlet subunit after being pretreated by the pretreatment subunit, and the rapid detection of the sample to be detected is realized. Correspondingly, the invention also provides a micro-fluidic chip system and a detection method of heavy metal ions in water.)

1. The utility model provides a micro-fluidic chip, includes the chip body, and sets up at least one detection function unit in the chip body, its characterized in that, every detection function unit is including sample inlet (6), preliminary treatment subunit (5) and at least one reaction detection subunit (3) that are linked together to and with at least one reagent appearance subunit (4) of advancing that reaction detection subunit (3) are linked together.

2. Microfluidic chip according to claim 1, characterized in that said pre-processing subunit (5) comprises: a spiral channel (51) surrounding the sample inlet (6) and communicated with the sample inlet (6), and a filter cell (52) respectively communicated with the spiral channel (51) and the reaction detection subunit (3);

the spiral channel (51) is uniformly provided with a plurality of sedimentation pits (53), the filter tank (52) is formed by communicating a plurality of sections of U-shaped channels (521), a filter membrane (522) is arranged at the joint of the two sections of U-shaped channels (521), or a filter membrane (522) is arranged in each section of U-shaped channel (521), and the last section of U-shaped channel (521) is communicated with at least one reaction detection subunit (3) through a connecting channel.

3. Microfluidic chip according to claim 1, characterized in that the pre-treatment subunit (5) comprises at least two sedimentation tanks (55) in sequential communication along the flow direction of the sample to be detected,

at least three sedimentation baffles (56) are uniformly arranged in each sedimentation tank (55) at intervals along the flowing direction of a sample to be detected, an adsorption part for removing organic matters is arranged at the top of each sedimentation tank (55), the last sedimentation tank (55) is connected with at least one reaction detection subunit (3) through at least one Y-shaped channel, and the other inlet of the at least one Y-shaped channel is respectively connected with a reagent sample inlet subunit (4).

4. The microfluidic chip according to claim 3, wherein the heights of at least three of the sedimentation baffles (56-1, 56-2, 56-3) are gradually increased along the flow direction of the sample to be detected; preferably, a first sedimentation baffle (56-1), a second sedimentation baffle (56-2) and a third sedimentation baffle (56-3) are sequentially arranged in the sedimentation tank along the flowing direction of the sample to be detected, wherein the top end of the first sedimentation baffle (56-1) is flush with the bottom of the inlet of the sedimentation tank (55); the top end of the second sedimentation baffle (56-2) is flush with the central axis of the inlet of the sedimentation tank (55); the height of the top end of the third sedimentation baffle (56-3) above the top of the inlet of the sedimentation tank (55) is half of the height of the inlet, and the height of the top end of the third sedimentation baffle (56-3) from the top of the sedimentation tank (55) is half of the height of the inlet.

5. The microfluidic chip according to claim 3 or 4, wherein the size of the communication channel (57) between two adjacent sedimentation tanks gradually decreases along the flow direction of the sample to be detected to form a horizontal frustum pyramid shape, and the upper bottom surface of the frustum pyramid faces the flow direction of the sample to be detected; preferably, the frustum pyramid is a quadrangular frustum pyramid with a rectangular cross section and a trapezoidal longitudinal cross section.

6. The microfluidic chip according to claim 2, wherein the chip body is circular, rectangular, or regular polygonal.

7. The microfluidic chip according to claim 6, wherein at least one of the detection function units is uniformly arranged along a circumferential direction of the circular chip body; alternatively, the first and second electrodes may be,

the chip body in a rectangular or regular polygonal shape is internally provided with one detection function unit corresponding to each side; wherein the content of the first and second substances,

the center of the chip body is provided with a reagent sample introduction pool, and the number of the reagent sample introduction pool corresponding to the detection function units is divided into subintervals with the same number as each of the reagent sample introduction subunits (4) in the detection function units.

8. The microfluidic chip according to claim 7, further comprising: at least one gas channel (10) in communication with the reagent sample injection cell; and/or a waste liquid storage subunit (11) is communicated between two adjacent reaction detection subunits (3).

9. A micro-fluidic chip system comprises the following components in sequence from top to bottom: cover plate, microfluidic chip and substrate, characterized in that, the microfluidic chip is the microfluidic chip of claims 1 to 8.

10. A method for detecting heavy metal ions in a water body is characterized by comprising the following steps:

sampling pretreatment: adding a sample to be detected into a sample inlet (6) in the microfluidic chip according to any one of claims 1 to 8, so that the sample to be detected flows into a Y-shaped channel in the microfluidic chip after being pretreated by a pretreatment subunit in the microfluidic chip;

adding a detection reagent for detection: adding a detection reagent into a reagent sample injection subunit (4) in the microfluidic chip according to any one of claims 1 to 8, so that the detection reagent flows into a Y-shaped channel in the microfluidic chip, is fully mixed with the sample to be detected, and then flows into a reaction detection subunit (3) to detect the sample to be detected;

wherein, when the heavy metal ion to be detected is Pb²⁺Then, glutathione metal nanoclusters are used as the detection reagent, and are used as fluorescent probes and Pb²⁺Fully combining, reading the fluorescence spectrum to perform qualitative or quantitative judgment; or, when the heavy metal ions to be detected are Cd²⁺When in use, the cysteine modified glutathione gold nanocluster is taken as the detection reagent and is taken as a fluorescent probe and Pb²⁺And (4) fully combining, and reading the fluorescence spectrum to perform qualitative or quantitative judgment.

Technical Field

The invention relates to the technical field of microfluidics, in particular to a microfluidic chip, a microfluidic chip system and a method for detecting heavy metal ions in water based on the microfluidic chip.

Background

With the rapid development of global economy, a large amount of heavy metals and metalloids enter the atmosphere, water, sediments, soil and biological environments in various ways such as mining, metal smelting, metal processing, chemical production, fossil fuel combustion, application of pesticides and fertilizers, and the like, causing serious environmental pollution. The pollution of the water body by the heavy metal ions refers to the pollution of the water body caused by the pollutants containing the heavy metal ions entering the water body. Heavy metal wastewater (containing heavy metal ions such as chromium, cadmium, copper, mercury, nickel, zinc and the like) generated in industrial production processes such as mining and metallurgy, mechanical manufacturing, chemical industry, electronics, instruments and the like is one of the industrial wastewater which has the most serious pollution to water and the greatest harm to human beings. Heavy metals in wastewater are not decomposed and destroyed by various common water treatment methods, but only transfer their existing positions and transform their physicochemical states. Therefore, heavy metal wastewater should be treated on site at the site of generation, mixed with other wastewater. If sludge and wastewater containing heavy metal ions are used as fertilizers and for irrigating farmlands, soil can be polluted, heavy metal ions in crops and aquatic organisms can be enriched after the crops and the water enter the water, and the heavy metal ions are seriously harmful to human bodies through food chains, so that detection of the heavy metal ions is highly valued by researchers.

At present, for a detection method of heavy metal ions, a large-scale analytical instrument is required for a traditional detection means, and currently, a wide range of analytical instruments are as follows: ultraviolet-visible spectrophotometer, absorption spectroscopy (AAS), Atomic Emission Spectroscopy (AES), Atomic Fluorescence Spectroscopy (AFS), coupled plasma mass spectroscopy (ICP-MS), and the like, however, these methods and techniques have the advantages of strong specificity, high sensitivity, and the like, but have some defects:

1) the instrument is expensive, the operating cost is high, the instrument is not easy to carry, and continuous monitoring and field measurement cannot be realized; the emerging detection method for detecting heavy metal ions by biochemical method is convenient to carry, but has the defects of insufficient precision and poor repeatability;

2) before detection, sampling is required in advance, pre-treatment is carried out on the sampled wastewater sample liquid, for example, impurities in the wastewater sample liquid are precipitated, oil stains and the like in the wastewater sample liquid are removed, so that interference on a detection result is avoided, and then the sample liquid subjected to the pre-treatment is detected by using the analyzer. The whole process needs different equipment to carry out pretreatment and detection on the wastewater sample liquid, so that the whole process is complex and tedious to operate, and the detection efficiency is also reduced.

With the continuous development of the microfluidic chip technology, a plurality of basic operation units such as sample pretreatment, biological and chemical reactions, separation detection and the like can be integrated on a chip with a micro-channel network or a nano-channel network through the microfluidic chip, and then a complex analysis process is completed by controlling a fluid, so that the microfluidic chip has the advantages of less sample and reagent consumption, short analysis time, easy realization of large-scale parallel determination and the like. Therefore, to above-mentioned problem, this application has designed a micro-fluidic chip, has integrated functional unit such as sample, preliminary treatment and detection for can directly sample, preliminary treatment and detect petroleum waste water on this micro-fluidic chip, thereby can detect heavy metal ion among the petroleum waste water fast.

Disclosure of Invention

In view of the above technical problems, an object of the present invention is to provide a microfluidic chip, which is portable and can rapidly detect heavy metal ions in a water body.

In order to solve the technical problems, the invention adopts the technical scheme that:

the utility model provides a micro-fluidic chip, includes the chip body, and sets up at least one in the chip body detects the functional unit, every detect the functional unit including the introduction of sample port, preliminary treatment subunit and at least one reaction detection subunit that are linked together, and with at least one reagent introduction subunit that the reaction detection subunit is linked together.

Further, each of the detection functional units further includes: and at least one waste liquid storage subunit communicated with at least one reaction detection subunit.

Wherein the preprocessing subunit includes: the spiral channel surrounds the sample inlet and is communicated with the sample inlet, and the filter tank is respectively communicated with the spiral channel and the reaction detection subunit; the spiral channel is uniformly provided with a plurality of sedimentation pits, the filtering tank is formed by communicating a plurality of sections of U-shaped channels, a filtering membrane is arranged at the joint of the two sections of U-shaped channels, or a filtering membrane is arranged in each section of U-shaped channel, and the last section of U-shaped channel is communicated with at least one reaction detection subunit through a connecting channel.

The pretreatment sub-unit comprises at least three sedimentation tanks which are sequentially communicated along the circulation direction of a sample to be detected, wherein at least three sedimentation baffles are uniformly arranged in each sedimentation tank at intervals along the circulation direction of the sample to be detected, an adsorption part for removing organic matters is arranged at the top of each sedimentation tank, the last sedimentation tank is connected with at least one reaction detection sub-unit through at least one Y-shaped channel, and the other inlet of the at least one Y-shaped channel is respectively connected with one reagent sample injection sub-unit.

Wherein, the heights of at least three sedimentation baffles are gradually increased along the flowing direction of the sample to be detected.

The device comprises a sedimentation tank, a first sedimentation baffle, a second sedimentation baffle and a third sedimentation baffle, wherein the number of the sedimentation baffles arranged in each sedimentation tank along the flow direction of a sample to be detected is three, and the first sedimentation baffle, the second sedimentation baffle and the third sedimentation baffle are sequentially arranged at the inlet end of the sedimentation tank and are close to the outlet end of the sedimentation tank, and the top end of the first sedimentation baffle is flush with the bottom of the inlet of the sedimentation tank; the top end of the second sedimentation baffle is flush with the central axis of the sedimentation tank inlet, namely the height of the second sedimentation baffle is equal to the height of the central axis of the sedimentation tank inlet; the height of the top end of the third sedimentation channel, which is higher than the top end of the sedimentation tank inlet, is half of the height of the inlet, and the height of the top end of the third sedimentation baffle from the top of the sedimentation tank is half of the height of the inlet.

The inlet of the sedimentation tank refers to one end of a channel between the sample inlet and the sedimentation tank, which corresponds to the side of the sedimentation tank, or one end of a communication channel between two adjacent sedimentation tanks, which corresponds to the side of the sedimentation tank.

The size of a communication channel between two adjacent sedimentation tanks is gradually reduced along the circulation direction of the sample to be detected to form a horizontal prismoid shape, and the upper bottom surface of the prismoid faces the circulation direction of the sample to be detected.

The frustum pyramid is a quadrangular frustum pyramid with a rectangular cross section and a trapezoidal longitudinal cross section.

The chip body is circular, rectangular or regular polygonal.

Furthermore, at least one detection function unit is uniformly arranged along the circumferential direction of the circular chip body; a reagent sample injection pool is arranged at the center of the chip body, and the reagent sample injection pool is divided into equal number of subintervals corresponding to the number of the detection functional units and is respectively used as a reagent sample injection subunit in each detection functional unit; preferably, the number of the detection functional units is four, each detection functional unit is correspondingly provided with two reaction detection subunits, the circulation direction of a sample to be detected in the detection functional unit faces the circle center of the circular chip body, and each reagent sample injection subunit is respectively communicated with the two reaction detection subunits in the corresponding detection functional unit through two connecting channels.

Furthermore, the chip body in a rectangular or regular polygonal shape is provided with one detection function unit corresponding to each side, the center of the chip body is provided with a reagent sample injection pool, and the number of the reagent sample injection pool corresponding to the detection function units is divided into equal number of subintervals to be respectively used as the reagent sample injection subunits in each detection function unit.

Further, the microfluidic chip further comprises: and the at least one gas channel is communicated with the reagent sample injection pool.

In view of the above technical problems, a second object of the present invention is to provide a microfluidic chip system, which comprises, from top to bottom: the chip comprises a cover plate, a micro-fluidic chip and a substrate, wherein the micro-fluidic chip is the micro-fluidic chip.

Based on the micro-fluidic chip or the micro-fluidic chip system, the invention also aims to provide a method for detecting heavy metal ions in a water body, which comprises the following steps:

sampling pretreatment: adding a sample to be detected into a sample inlet in the microfluidic chip, so that the sample to be detected flows into a Y-shaped channel in the microfluidic chip after being pretreated by a pretreatment subunit in the microfluidic chip;

adding a detection reagent for detection: adding a detection reagent into the reagent sample injection subunit in the microfluidic chip, so that the detection reagent flows into the Y-shaped channel in the microfluidic chip, is fully mixed with the sample to be detected, and then flows into the reaction detection subunit to detect the sample to be detected;

wherein, when the heavy metal ion to be detected is Pb²⁺Then, glutathione metal nanoclusters are used as the detection reagent, and are used as fluorescent probes and Pb²⁺Fully combining, reading the fluorescence spectrum to perform qualitative or quantitative judgment; or, when the heavy metal ions to be detected are Cd²⁺When in use, the cysteine modified glutathione gold nanocluster is taken as the detection reagent and is taken as a fluorescent probe and Pb²⁺And (4) fully combining, and reading the fluorescence spectrum to perform qualitative or quantitative judgment.

The invention has the advantages that:

the invention discloses a micro-fluidic chip, which comprises a chip body and only one detection functional unit arranged in the chip body, wherein the detection functional unit comprises a sample inlet, a pretreatment subunit, a reaction detection subunit and a reagent sample inlet subunit, so that petroleum wastewater can be added through the sample inlet to wait for detecting a water sample, the petroleum wastewater enters the reaction detection subunit to react with a detection reagent flowing into the reaction detection subunit after being added through the reagent sample inlet subunit after being pretreated through the pretreatment subunit, the rapid detection of the sample to be detected is realized, the micro-fluidic chip is convenient to carry, large-scale detection and analysis equipment is not needed, and the detection cost is reduced.

Furthermore, the spiral channel in the pretreatment subunit in the microfluidic chip is provided with the precipitation pit, and the filter tank is provided with the filter membrane, so that organic matters such as suspended particulate matters, floating oil and the like in the sample to be detected can be effectively separated and precipitated, the adverse effect on detection is avoided, and the detection accuracy is improved.

Furthermore, the sedimentation baffle and the adsorption piece are respectively arranged in the sedimentation tank in the pretreatment subunit in the microfluidic chip to effectively separate and precipitate suspended particulate matters, floating oil and other organic matters in the sample to be detected, so that the adverse effect on the detection is avoided, and the detection accuracy is improved; and a special connecting channel is arranged between the sedimentation tanks, so that the sedimentation effect is further improved.

Furthermore, at least one detection functional unit is arranged on the micro-fluidic chip, so that sample injection can be simultaneously carried out from the sample injection port of the at least one detection functional unit, and the sample to be detected can be simultaneously detected in the eight reaction detection subunits only by adding a detection reagent into the reagent sample injection pool positioned at the center, thereby realizing high-throughput rapid detection.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of a microfluidic chip according to the present invention;

FIG. 2 is a schematic diagram of a spiral channel in a preprocessing subunit of the microfluidic chip of FIG. 1;

FIG. 3 is a schematic diagram of a filter cell in a pretreatment sub-unit of the microfluidic chip of FIG. 1;

FIG. 4 is a schematic structural diagram of a second embodiment of a microfluidic chip according to the present invention;

FIG. 5 is a schematic diagram of an embodiment of a pre-processing subunit in the microfluidic chip of FIG. 4;

FIG. 6a is a schematic view showing the lower half of the settling tank and the settling baffles processed on the first chip processing layer;

FIG. 6b is a schematic view reflecting the upper half of the sedimentation basin processed on the second chip processing layer;

FIG. 6c is a schematic diagram showing the combination of the deposition pool and the deposition baffle obtained by bonding the first chip processing layer in FIG. 6a and the second chip processing layer in FIG. 6 b;

fig. 7a is a schematic structural diagram of a third embodiment of a microfluidic chip according to the present invention;

FIG. 7b is a schematic view showing that a sample-adding partition plate is disposed in the reagent sample-feeding cell in FIG. 7 a;

FIG. 8 is a simulation graph reflecting the flow rate of liquid in the microfluidic chip of FIG. 4;

FIG. 9 is a schematic diagram showing the effect of settling of particulate matter in the liquid in the microfluidic chip of FIG. 4 under the action of the settling baffles;

FIG. 10 is a simulation graph reflecting the flow rate of the sample to be tested in the sedimentation tank shown in FIG. 5;

FIG. 11 shows the application of GSH-AuNCs as detection reagent to Pb in petroleum wastewater in the microfluidic chip of FIG. 4²⁺Carrying out a specific detection effect curve chart;

FIG. 12 shows the detection of Cd in petroleum wastewater by Cys-GSH-AuNCs in the microfluidic chip of FIG. 4²⁺Carrying out a specific detection effect curve chart;

FIG. 13 is a graph showing the relative fluorescence intensities of GSH-AuNCs of eight metal ions in petroleum wastewater at an emission wavelength of 590 nm.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The examples are given for the purpose of better illustration of the invention, but the invention is not limited to the examples. Therefore, those skilled in the art should make insubstantial modifications and adaptations to the embodiments of the present invention in light of the above teachings and remain within the scope of the invention.

The micro-fluidic chip of the invention pretreats and detects heavy metal ions in water by arranging at least one detection functional unit in the chip body, concretely, a sample to be detected (such as petroleum wastewater) is added from a sample inlet 6 of the detection functional unit, then the sample to be detected flows into a pretreatment subunit 5 through the sample inlet 6 to separate and precipitate a large amount of impurities such as silt, oil stain, organic matters, microorganisms and the like in the sample to be detected, then flows into the reaction detection subunit 3 to react with a detection reagent (such as glutathione gold nanocluster detection liquid, specifically, a reagent is added into the reagent sample injection subunit 4 of the detection functional unit and then flows into the reaction detection subunit 3), so that the purposes of express delivery and simple detection are achieved, the carrying is convenient, the detection cost is greatly reduced, and the efficiency is improved; in addition, a plurality of detection functional units can be arranged in the chip body according to actual needs, so that the purposes of high flux and rapid detection are achieved. The microfluidic chip and the system thereof according to the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.