A microfluidic plate, its uses, and a total phosphorus detection method

Abstract

The present invention provides a microfluidic plate, its use and a total phosphorus detection method. The microfluidic plate includes: a liquid inlet; a mixing buffer chamber communicating with the liquid inlet; the mixing buffer chamber includes a waveform flow channel, and buffer bins are provided at the peaks and / or valleys of the waveform flow channel; an incubation chamber communicating with the mixing buffer chamber; and a detection chamber communicating with the incubation chamber. The microfluidic plate of the present invention includes a mixing buffer chamber, and buffer bins are provided at the peaks and / or valleys of the waveform flow channel. The buffer bins increase the tolerance space, which can effectively reduce the accuracy requirements for the metering pump. When the flow rates of several liquids fluctuate, the buffer bins can keep the mixing effect at a relatively high level.

Description

Technical Field

[0001] The present invention relates to the field of water quality analysis, and particularly to a microfluidic plate, its uses, and a total phosphorus detection method. Background Art

[0002] Total phosphorus is the general term for elemental phosphorus, pyrophosphate, orthophosphate, condensed phosphate, metaphosphate, and phosphate combined with organic groups. The main pollution sources of total phosphorus are domestic sewage, chemical fertilizers, organophosphorus pesticides, and phosphate builders used in modern detergents. Moreover, phosphorus is a key element necessary for the growth of algae in water, but excessive phosphorus content will cause the water body to become foul and emit an odor, leading to eutrophication of the water body and even red tides. Currently, the main methods for removing total phosphorus from water are: chemical precipitation method, biological method, ion exchange method, adsorption method, membrane separation method, etc. These methods play different key roles in different fields. Before treating phosphorus-polluted water bodies, it is necessary to determine the content of total phosphorus in the water body so as to formulate the best treatment plan.

[0003] With the breakthrough progress made in materials science, micro-nano processing technology, and microelectronics, microfluidic chips have also developed rapidly. A microfluidic chip, also known as a "lab-on-a-chip", is based on micro-electromechanical processing technology. Microchannel networks are fabricated on materials such as silicon wafers, glass, or polydimethylsiloxane (PDMS), enabling controllable fluids to flow through the microchannel networks, thereby realizing operations such as reactions, separations, and detections in the fields of biology and chemistry. Currently, the microfluidic plates used in the field of total phosphorus detection have poor mixing and reaction effects and low detection accuracy. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a microfluidic plate, a total phosphorus detection device, and a total phosphorus detection method.

[0005] To achieve the above purpose and other related purposes, the first aspect of the present invention provides a microfluidic plate, comprising:

[0006] A liquid inlet;

[0007] A mixing buffer chamber communicating with the liquid inlet; the mixing buffer chamber includes a waveform flow channel, and buffer bins are provided at the peaks and / or valleys of the waveform flow channel;

[0008] An incubation chamber communicating with the mixing buffer chamber;

[0009] A detection chamber communicating with the incubation chamber.

[0010] The second aspect of the present invention provides the use of the above microfluidic plate for total phosphorus detection.

[0011] The third aspect of the present invention provides a total phosphorus detection method, which is applied to the microfluidic plate as described above. The method includes:

[0012] The sample liquid flow to be measured and the reagent capable of reacting with the sample liquid flow to be measured enter through the feed port, and successively pass through the mixing buffer chamber, the incubation chamber and the detection chamber. The absorbance of the sample liquid flow to be measured after color development is detected, and the total phosphorus concentration in the sample liquid flow to be measured is calculated according to the absorbance.

[0013] Preferably, the reagent includes ammonium molybdate solution and ascorbic acid.

[0014] More preferably, it further includes at least one of the following technical features:

[0015] 1) The volume ratio of the sample liquid flow to be measured to the ammonium molybdate solution is 10:1 to 20:1; the volume ratio of the sample liquid flow to be measured to the ascorbic acid is 10:1 to 20:1;

[0016] 2) The ammonium molybdate solution enters through the first feed port, the sample liquid flow to be measured enters through the second feed port, and the ascorbic acid enters through the third feed port. The sample liquid flow to be measured enters through the second feed port, first mixes with the ammonium molybdate solution, and then mixes and reacts with the ascorbic acid after the reaction.

[0017] As described above, the present invention has the following beneficial effects:

[0018] The microfluidic plate of the present invention includes a mixing buffer chamber, and the mixing buffer chamber includes a waveform flow channel. Buffer bins are provided at the wave crests and / or wave troughs of the waveform flow channel. The buffer bins increase the tolerance space, which can effectively reduce the precision requirements for the metering pump. In traditional microfluidic control, in order to achieve micro-level control, generally expensive pressure pumps are used. After adding the buffer bins, ordinary syringe pumps can be used to replace the expensive pressure pumps. When the flow rates of several liquids fluctuate, the buffer bins can keep the mixing effect at a relatively high level. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It shows a schematic diagram of the overall structure of the microfluidic plate of the present invention.

[0020] Figure 2 It shows Figure 1 The bottom view structure diagram of the microfluidic plate.

[0021] Figure 3 It shows Figure 1 The exploded view of the microfluidic plate.

[0022] Figure 4 It shows Figure 1 The bottom view exploded view of the microfluidic plate.

[0023] Figure 5 Shown as Figure 1 Schematic diagram of the internal structure of the microfluidic plate

[0024] Reference numerals

[0025] 1 Liquid inlet

[0026] 11 First feed inlet

[0027] 12 Second feed inlet

[0028] 13 Third feed inlet

[0029] 2 Mixing buffer chamber

[0030] 21 Wave channel

[0031] 22 Buffer bin

[0032] 3 Incubation chamber

[0033] 4 Detection chamber

[0034] 41 Necking

[0035] 42 First detection sub-chamber

[0036] 43 Second detection sub-chamber

[0037] 5 External channel

[0038] 6 Liquid outlet

[0039] 7 Fixed through-hole Detailed implementation manners

[0040] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification

[0041] Please refer to Figures 1 to 5 . It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have technical essential significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented

[0042] As Figures 1 to 5 shown, a microfluidic plate includes:

[0043] A liquid inlet 1;

[0044] A mixing buffer chamber 2, which is communicated with the liquid inlet 1; the mixing buffer chamber 2 includes a waveform flow channel 21, and buffer bins 22 are arranged at the wave peaks and / or wave valleys of the waveform flow channel 21;

[0045] An incubation chamber 3, which is communicated with the mixing buffer chamber 2;

[0046] A detection chamber 4, which is communicated with the incubation chamber 3.

[0047] The liquid inlet 1 is used to receive a liquid flow sample to be measured and / or receive a reagent that can react with the liquid flow sample to be measured. The mixing buffer chamber 2 is used to mix and buffer the liquid flow sample to be measured and the reagent. The incubation chamber 3 is used to incubate the liquid flow sample to be measured and the reagent. The detection chamber 4 is used to accommodate the incubated liquid flow sample to be measured and perform detection.

[0048] The microfluidic plate of the present invention includes a mixing buffer chamber. The mixing buffer chamber includes a waveform flow channel, and buffer bins are arranged at the wave peaks and / or wave valleys of the waveform flow channel. The buffer bins increase the tolerance space, which can effectively reduce the accuracy requirements for the metering pump. In traditional microfluidic control, in order to achieve micro-level control, generally expensive pressure pumps are used. After adding the buffer bins, ordinary syringe pumps can be used to replace expensive pressure pumps. When the flow rates of several liquids fluctuate, the buffer bins can keep the mixing effect at a relatively high level.

[0049] Because it takes time for the chemical reaction between the liquid flow sample to be measured and the reagent, the mixed liquid flow sample to be measured and the reagent enter the incubation chamber 3, wait for 10 - 20 minutes, and then perform detection.

[0050] In a preferred embodiment, as Figure 5 shown, the waveform flow channel connecting the wave peaks and wave valleys is serrated. The serrated shape has good mixing effect, which can cause violent stirring and mixing of the liquid when it contacts the serrated flow channel, and is more effective than the traditional T-shaped mixing flow channel and serpentine mixing flow channel.

[0051] In a preferred embodiment, as Figure 2 and Figure 3 shown, the number of the liquid inlets 1 is one or more.

[0052] In a preferred embodiment, as Figure 2 and Figure 5As shown, the number of the feed ports 1 is three, including a first feed port 11, a second feed port 12, and a third feed port 13. The first feed port 11 and the second feed port 12 converge through a flow channel and then converge with the third feed port 13 through a flow channel.

[0053] In a preferred embodiment, the volume of the buffer chamber 22 is 0.2 - 0.6 microliters. To not affect the fluidity of the liquid to be measured, the buffer chamber can be set to 0.2 - 0.6 microliters, and the liquid to be measured can be easily emptied.

[0054] In a preferred embodiment, as Figure 3 and Figure 4 shown, the incubation chamber 3 communicates with the outside.

[0055] In a preferred embodiment, as Figure 3 and Figure 4 shown, the microfluidic plate further includes an external channel 5, and the external channel 5 communicates with the incubation chamber 3.

[0056] In a preferred embodiment, as Figure 5 shown, the detection chamber 4 is provided with a constriction 41, and the constriction 41 divides the detection chamber 4 into a first detection sub-chamber 42 and a second detection sub-chamber 43 that communicate with each other. The first detection sub-chamber 42, the constriction 41, and the second detection sub-chamber 43 together form an optical detection channel. The detection channel of the prior art does not have a constriction 41 and is a straight-through structure. However, due to the certain depth (3 - 5 mm) of the detection channel itself, the liquid often cannot be filled. After the constriction 41 is provided in the detection chamber 4, a certain head resistance can be given to the fluid, so that the fluid fills the second detection sub-chamber 43. After being filled, due to the surface tension of the liquid, the upper and lower surfaces of the cavity can be filled. The width of the constriction 41 can be set within 1 mm.

[0057] In a preferred embodiment, the microfluidic plate further includes a liquid outlet 6, the liquid outlet 6 and / or the liquid inlet 1.

[0058] In a preferred embodiment, the microfluidic plate further includes a driving pump, and the driving pump communicates with the liquid outlet 6. This design is used to pump the liquid that has reacted in the incubation chamber 3 into the detection chamber 4.

[0059] The microfluidic plate can be as Figure 1 and Figure 4As shown in the figure, it is divided into three layers, namely the upper layer board, the middle layer board, and the lower layer board. Fixed through holes 7 can be provided and fixed by screws, positioning pins, etc. The external channel 5 is fixed on the upper layer board, the flow channel is arranged on the middle layer board, and a closed flow channel is formed through cooperation with the lower layer board. The lower layer board is provided with a liquid inlet 1 and a liquid outlet 6 for inlet and outlet of water. Since absorbance needs to be detected during total phosphorus detection, at least the materials of the middle layer board, the lower layer board that form the detection cavity 4, and the upper layer board corresponding to the detection cavity are transparent materials. For example, the materials of the middle layer board, the lower layer board that form the detection cavity 4, and the upper layer board corresponding to the detection cavity are transparent materials, or all the materials of the microfluidic board are transparent materials.

[0060] Embodiment

[0061] When using the microfluidic board of the present invention for total phosphorus detection, the microfluidic board includes:

[0062] A liquid inlet 1 for receiving a sample of the liquid flow to be measured and / or receiving a reagent that can react with the sample of the liquid flow to be measured; the number of the feed inlets 1 is three: a first feed inlet 11, a second feed inlet 12, and a third feed inlet 13. The first feed inlet 11 and the second feed inlet 12 are combined through a flow channel and then combined with the third feed inlet 13 through a flow channel;

[0063] A mixing and buffering cavity 2 communicated with the liquid inlet 1 for mixing and buffering the sample of the liquid flow to be measured and the reagent; the mixing and buffering cavity 2 includes a waveform flow channel 21, and buffer bins 22 are provided at the wave peaks and / or wave valleys of the waveform flow channel 21; the waveform flow channel connecting the wave peaks and wave valleys is serrated; the volume of the buffer bin 22 is 0.44 uL;

[0064] An incubation cavity 3 communicated with the mixing and buffering cavity 2 for incubating the sample of the liquid flow to be measured and the reagent; the incubation cavity 3 is communicated with the outside; the microfluidic board further includes an external channel 5, and the external channel 5 is communicated with the incubation cavity 3;

[0065] A detection cavity 4 communicated with the incubation cavity 3 for accommodating the incubated sample of the liquid flow to be measured; the detection cavity 4 is provided with a constriction 41, and the constriction 41 divides the detection cavity 4 into a first detection sub-cavity 42 and a second detection sub-cavity 43 that are communicated; the width of the constriction 41 is set at 0.8 mm;

[0066] The microfluidic board further includes a liquid outlet 6, and the liquid outlet 6 is communicated with the detection cavity 4; the microfluidic board further includes a driving pump, and the driving pump is communicated with the liquid outlet 6.

[0067] A total phosphorus detection method, characterized in that it is applied to the microfluidic plate of this embodiment. The method includes: allowing a liquid sample to be measured and a reagent capable of reacting with the liquid sample to enter through a feed port, sequentially passing through a mixing buffer chamber, an incubation chamber, and a detection chamber, detecting the absorbance of the liquid sample to be measured after color development, and calculating the total phosphorus concentration in the liquid sample to be measured based on the absorbance. The reagent includes ammonium molybdate solution and ascorbic acid. The volume ratio of the liquid sample to be measured to the ammonium molybdate solution is 15:1; the volume ratio of the liquid sample to be measured to the ascorbic acid is 15:1. The ammonium molybdate solution enters through the first feed port, the liquid sample to be measured enters through the second feed port, and the ascorbic acid enters through the third feed port. The measured data are shown in the following table.

[0068] True value of total phosphorus concentration Measured value of total phosphorus concentration Error 0.1 ppm 0.101 ppm 1.00％ 0.2 ppm 0.194 ppm -3.00％ 0.4 ppm 0.387 ppm -3.25％ 0.6 ppm 0.602 ppm 0.33％ 0.8 ppm 0.787 ppm -1.63％ 1 ppm 0.985 ppm -1.50％

[0069] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A microfluidic plate, characterized in that, Comprising: A liquid inlet (1); A mixing buffer chamber (2), which is in communication with the liquid inlet (1); the mixing buffer chamber (2) includes a waveform flow channel (21), and buffer bins (22) are provided at the wave crests and / or wave troughs of the waveform flow channel (21); An incubation chamber (3), the incubation chamber (3) is in communication with the mixing buffer chamber (2); A detection chamber (4), which is in communication with the incubation chamber (3); The waveform flow channel connecting the wave crest and the wave trough is serrated; The detection chamber (4) is provided with a constriction (41), and the constriction (41) divides the detection chamber (4) into a communicating first detection sub-chamber (42) and second detection sub-chamber (43); The volume of the buffer bin (22) is 0.2 to 0.6 microliters.

2. The microfluidic plate according to claim 1, characterized in that, It further includes at least one of the following technical features: 1) The number of the liquid inlets (1) is one or more; 2) The incubation chamber (3) is in communication with the outside.

3. The microfluidic plate according to claim 2, characterized in that, In feature 1), the number of the liquid inlets (1) is three, including a first feed inlet (11), a second feed inlet (12) and a third feed inlet (13), and the first feed inlet (11) and the second feed inlet (12) converge through a flow channel and then converge with the third feed inlet (13) through a flow channel.

4. The microfluidic plate according to claim 2, characterized in that, In feature 2), the microfluidic plate further includes an outside channel (5), and the outside channel (5) is in communication with the incubation chamber (3).

5. The microfluidic plate according to claim 1, characterized in that, The microfluidic plate further includes a liquid outlet (6), and the liquid outlet (6) is in communication with the detection chamber (4).

6. The microfluidic plate according to claim 5, characterized in that, The microfluidic plate further includes a driving pump, and the driving pump is in communication with the liquid outlet (6) and / or the liquid inlet (1).

7. The microfluidic plate according to any one of claims 1 to 6 is used for total phosphorus detection.

8. A total phosphorus detection method, characterized in that, Applied to the microfluidic plate according to any one of claims 1 to 6, the method includes: A sample of the liquid flow to be measured and a reagent capable of reacting with the sample of the liquid flow to be measured enter through the feed inlet, successively pass through the mixing buffer chamber, the incubation chamber and the detection chamber, the absorbance of the sample of the liquid flow to be measured after color development is detected, and the total phosphorus concentration in the sample of the liquid flow to be measured is calculated according to the absorbance.

9. The total phosphorus detection method according to claim 8, characterized in that, The reagent includes ammonium molybdate solution and ascorbic acid.

10. The total phosphorus detection method according to claim 9, characterized in that, It further includes at least one of the following technical features: 1) The volume ratio of the sample of the liquid flow to be measured to the ammonium molybdate solution is 10:1 to 20:1; the volume ratio of the sample of the liquid flow to be measured to the ascorbic acid is 10:1 to 20:1; 2) The ammonium molybdate solution enters through the first feed inlet, the sample of the liquid flow to be measured enters through the second feed inlet, and the ascorbic acid enters through the third feed inlet.

Images