Method for detecting protein in water body based on smart phone

Abstract

The invention discloses a method for detecting protein in a water body based on a smart phone, and belongs to the technical field of protein detection. According to the portable detection equipment based on the smart phone, laser emitted by a laser pen is divided into two beams through a beam splitter, then a to-be-detected liquid is compared with a reference solution, the smart phone is used for shooting and identifying RGB values, the A ratio of the to-be-detected liquid to the reference solution is obtained, the linear relation between proteins with different concentrations and the A value is constructed, and the detection accuracy is improved. Compared with a traditional detection method, the method has the advantages that the sensitivity is higher, and on-site detection of a to-be-detected water sample is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of protein detection in water, and in particular to a method for protein detection in water based on a smart phone. Background Art

[0002] There are many methods for determining protein content. Commonly used techniques include Kjeldahl nitrogen determination, colorimetry (such as biuret method, Lowry method, Bradford method) and ultraviolet absorption method. Each method has its advantages and limitations. The selection of the appropriate method depends on the specific needs of the experiment, the required sensitivity and the characteristics of the sample. Kjeldahl nitrogen determination is a classic method for determining protein content. The protein content is indirectly estimated by measuring the nitrogen content in the sample. This method has high accuracy and good reproducibility, but the operation is complicated and time-consuming.

[0003] The colorimetric method is based on the color change produced after the protein reacts with a specific reagent to determine its content, including the following main methods: The biuret method uses the peptide bonds in the protein to react with the biuret reagent to form a purple complex with a maximum absorption peak at 540 nm. This method is simple and fast, but has low sensitivity to low concentrations of protein. The Lowry method combines the biuret reaction with the redox reaction of the Folin phenol reagent, has high sensitivity, and is suitable for the detection of trace amounts of protein. However, this method is sensitive to many interfering substances (such as reducing agents and sugars). In the ultraviolet absorption method, proteins have a natural absorption peak at a wavelength of 280 nm, which is due to the absorption of aromatic amino acid residues (such as tryptophan and tyrosine). This method is fast and non-destructive, but requires a relatively pure sample and is easily interfered by other absorbing substances.

[0004] The Bradford method uses the color change of Coomassie Brilliant Blue G-250 dye after binding to protein to determine protein content. Coomassie Brilliant Blue dye changes from brown-red to blue after binding to protein, and the protein content is calculated by measuring its absorbance change at 595 nm. The specific steps are as follows: Prepare a standard curve: Use a standard protein of known concentration (such as bovine serum albumin, BSA) to prepare a series of standard solutions. Add dye: Add Coomassie Brilliant Blue dye to the standard solution and the sample solution to be tested, mix well and let it stand for a few minutes. Determine absorbance: Measure the absorbance of each standard solution and sample solution at 595 nm. Calculate protein concentration: Calculate the protein concentration of the sample to be tested based on the standard curve. This method is widely used in biochemical laboratories due to its simplicity, rapidity and high sensitivity.

[0005] Although there are many methods for detecting absorbance and the measurements are accurate, most sensors or precision instruments involved can only be used in laboratory environments with relatively harsh conditions, and there is a lack of rapid on-site detection methods. Summary of the invention

[0006] In order to solve the technical problem of difficulty in on-site detection of protein content in the prior art, the present invention provides a method for detecting protein in water based on a smartphone. The present invention uses a liquid to be tested and a reference solution as a comparison, and uses a smartphone to shoot and identify RGB values, thereby obtaining the negative logarithm of the G ratio of the liquid to be tested and the reference solution, constructing a linear relationship, and realizing rapid and accurate detection of protein in water.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] On the one hand, the present invention provides a portable detection device based on a smart phone, including a laser pen, a light source reflector, a beam splitter, a reflector, a cuvette, a cover, a laser pen fixing tube and a detection box;

[0009] An L-shaped partition is provided in the detection box, which is used to separate the detection box into a light mirror area and a sample area; the partition is provided with light-transmitting holes, and the light-transmitting holes include a first light-transmitting hole and a second light-transmitting hole;

[0010] The optical mirror area is used to place the light source reflector, beam splitter and reflector. The laser emitted by the laser pen irradiates the light source reflector, and the light is reflected to the beam splitter through the light source reflector. The sample area is used to place the cuvette, and the cuvette includes a first cuvette and a second cuvette.

[0011] In the optical mirror area, an incident hole is provided on the side wall of the detection box, and the laser pen fixing tube is used to fix the laser pen on the side wall of the detection box. The laser emitted by the laser pen is irradiated onto the light source reflector through the incident hole, and then reflected onto the beam splitter, and the beam splitter splits the laser into two beams of laser light with the same power and parallel to each other; one beam of laser light is irradiated onto the first cuvette through the first light-transmitting hole, and the other beam of laser light is irradiated onto the reflector, and then reflected by the reflector and irradiated onto the second cuvette through the second light-transmitting hole;

[0012] The cover is arranged on the top of the detection box, so that the detection box forms a darkroom; a mobile phone camera shooting hole is provided on the side wall of the detection box corresponding to the middle position between the first cuvette and the second cuvette; a smartphone fixing groove for placing a smartphone is also provided on the side wall of the detection box where the mobile phone camera shooting hole is located, and the smartphone is placed in the smartphone fixing groove, and the camera is aimed at the mobile phone camera shooting hole to take pictures of the sample area.

[0013] Preferably, a support frame is provided below the laser pen fixing tube for supporting the laser pen fixing tube;

[0014] The bottom of the detection box is provided with two sample slots, namely a first sample slot and a second sample slot, wherein the first sample slot is used to fix the first cuvette, and the second sample slot is used to fix the second cuvette;

[0015] Three positioning posts are fixed on the bottom of the detection box, namely the first positioning post, the second positioning post and the third positioning post, and threads are provided on the tops of the positioning posts; the beam splitter is fixed by the beam splitter optical adjustment frame, the reflector is fixed by the reflector optical adjustment frame, and the light source reflector is fixed by the light source reflector frame, and the bottoms of the beam splitter optical adjustment frame, the reflector optical adjustment frame and the light source reflector frame are all provided with internal threads, which cooperate with the threads on the tops of the positioning posts, and the beam splitter optical adjustment frame, the reflector optical adjustment frame and the light source reflector frame are respectively fixed on the first positioning post, the second positioning post and the third positioning post.

[0016] On the other hand, the present invention also provides a method for detecting protein in water based on a smart phone, comprising step 1: preparing a protein standard solution;

[0017] Step 2: Mix the protein standard solution with the dye and react at room temperature until the color is stable;

[0018] Step 3: adding the protein solution dyed in step 2 as a sample solution to the portable detection device according to claim 1 or 2, using distilled water as a reference, turning on the laser pen of the portable detection device, and then taking relevant photos using a smart phone;

[0019] Step 4: Cut out the effective area of ​​the photograph, and obtain the R, G, and B values ​​of the corresponding areas of the sample solution and the reference solution, and then calculate the A value according to formula (I);

[0020] (I);

[0021] Step 5: Take photos of the mixed solutions of protein standard solutions and dye solutions with different concentrations in sequence, intercept the effective areas of each solution to identify the corresponding R, G, and B values, calculate the A value in each picture, and establish a standard working curve with protein concentration as the horizontal axis and A as the vertical axis;

[0022] Step 6: After the water sample to be tested is pretreated, the corresponding A is determined by analogy with the above steps S2-S4, and the protein concentration of the water sample to be tested is calculated in combination with the standard working curve.

[0023] Preferably, in step 1, the protein is bovine serum albumin (BSA); step 1 specifically comprises: preparing protein standard solutions with concentrations of 128ug / L, 144ug / L, 160ug / L, 176ug / L, 192ug / L, 208ug / L, 224ug / L, and 240ug / L.

[0024] Furthermore, the step 2 is specifically as follows: 2 mL of the protein standard solution is mixed with 2 mL of 100 mg / L Coomassie Brilliant Blue dye, and reacted at room temperature for 5-30 minutes to stabilize the color.

[0025] Furthermore, the step 3 is specifically as follows: 3 mL of the dyed protein solution is added to a 5 mL centrifuge tube, placed in a portable detection device, using distilled water as a reference, turning on the laser pen of the device, and then taking pictures, and each group is repeated 3 times.

[0026] Furthermore, the laser pen emits a laser with a wavelength of 500-550 nm.

[0027] Furthermore, in step 4, the image is processed using Matlab software; the effective area is the light column area formed by the laser beam passing through the solution in the cuvette.

[0028] Furthermore, in step 6, a water sample to be tested is collected, filtered through a 0.45 μm pore size filter syringe, and then the pH of the solution to be tested is adjusted to neutral using hydrochloric acid or sodium hydroxide solution for testing.

[0029] The present invention uses the detection box as the device shell, which not only fixes the position of each device, but also creates a dark environment for detection to avoid interference from the external environment.

[0030] The present invention uses a commercially available laser pen as a light source. For example, a commercially available laser pen can emit a light beam with a wavelength of 532 nm. After passing through three optical lenses, namely, a light source reflector, a beam splitter, and a reflector, the light beam is divided into two parallel beams that are perpendicular to the light beams irradiated by the laser pen before the optical lens is illuminated, and the light beams are irradiated into the corresponding cuvette through the light transmission hole. A mobile phone camera shooting hole is provided on the side wall of the detection box, and a smart phone fixing groove is fixed on the outer wall for taking pictures of the sample area. The internal components of the device are simple, without any cumbersome operation, and can be used on site after simple assembly.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention discloses a portable device based on a smart phone, and is used for detecting protein in water. The portable device of the present invention is used as a detection device to construct a standard linear curve of protein, and the smart phone is used to shoot and identify RGB values, so as to obtain a linear relationship between different concentrations of protein and A. The water sample to be tested is detected by the portable device of the invention, and the protein concentration of the water sample can be quickly and accurately determined. The present invention reduces the demand for actual water sample detection conditions, takes the actual water sample to be tested as the analysis basis, and realizes the protein determination of the actual water sample, which is convenient and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a three-dimensional diagram of a portable detection device based on a smart phone according to Embodiment 1 of the present invention;

[0034] Figure 2 The internal structure of the detection box of Example 1 of the present invention Figure 1 ;

[0035] Figure 3 The internal structure of the detection box of Example 1 of the present invention Figure 2 ;

[0036] Figure 4 The internal structure of the detection box of Example 1 of the present invention Figure 3 ;

[0037] Figure 5 The internal structure of the detection box of Example 1 of the present invention Figure 4 ;

[0038] Among them, 1 is a beam splitter, 2 is a reflector, 3 is a cuvette, 3-1 is a first cuvette, 3-2 is a second cuvette, 4 is a cover, 5 is a light source reflector, 6 is a light source reflector frame, 7 is a smart phone fixing slot, 8 is a mobile phone camera shooting hole, 9 is a laser pen fixing tube, 10 is a detection box, 11 is a partition, 12 is a light transmission hole, 12-1 is a first light transmission hole, 12-2 is a second light transmission hole; 13 is an incident hole, 14 is a laser pen, 15 is a support frame, 16 is a positioning column, 16-1 is a first positioning column, 16-2 is a second positioning column, 17 is a sample slot, 17-1 is a first sample slot, 17-2 is a second sample slot, 18 is a beam splitter optical adjustment frame, 19 is a reflector optical adjustment frame;

[0039] Figure 6 This is a picture of the sample area taken in step 3 of Example 2 of the present invention, with the reference on the right and the sample on the left;

[0040] Figure 7 This is a standard working curve diagram of protein concentration and A value in Example 2;

[0041] Figure 8 It is a valid area division map;

[0042] Fig. 9 The A value distribution diagram of the surrounding area under different protein concentrations;

[0043] Fig.10 Example 2 protein concentration and Standard working curve diagram of values;

[0044] Fig.11 The figure is a comparison of the results of measuring protein content in water samples using a standard spectrophotometer and SPSD. DETAILED DESCRIPTION

[0045] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0046] In the present invention, the materials and reagents used can be obtained from commercial sources unless otherwise specified. The optical lenses in the portable detection device based on a smart phone in the present invention are shown in Table 1 below.

[0047] Table 1

[0048]

[0049] The present invention provides a method for detecting protein in water based on a smart phone, and specific embodiments are as follows.

[0050] Example 1

[0051] A smartphone-based portable detection device (SPSD), such as Figure 1-5 , including a laser pen 14, a beam splitter 1, a reflector 2, a cuvette 3, a cover 4, a light source reflector 5, a smart phone fixing slot 7, a mobile phone camera shooting hole 8, a laser pen fixing tube 9 and a detection box 10;

[0052] An L-shaped partition 11 is provided in the detection box 10, which is used to separate the detection box 10 into a light mirror area and a sample area; a light-transmitting hole 12 is provided on the partition 11, and the light-transmitting hole 12 includes a first light-transmitting hole 12-1 and a second light-transmitting hole 12-2;

[0053] The optical mirror area is used to place the light source reflector 5, the beam splitter 1 and the reflector 2. The laser emitted by the laser pen 14 irradiates the light source reflector 5, and the light is reflected to the beam splitter 1 by the light source reflector 5. The sample area is used to place the cuvette 3, and the cuvette 3 includes a first cuvette 3-1 and a second cuvette 3-2.

[0054] In the optical mirror area, an incident hole 13 is provided on the side wall of the detection box 10, and the laser pen fixing tube 9 is used to fix the laser pen 14 on the side wall of the detection box 10. The laser emitted by the laser pen 14 is irradiated onto the light source reflector 5 through the incident hole 13, and then reflected onto the beam splitter 1. The beam splitter 1 is used to split the laser into two laser beams with little difference in power and perpendicular to each other; one of the laser beams is irradiated onto the first cuvette 3-1 through the first light-transmitting hole 12-1, and the other laser beam is irradiated onto the reflector 2, and is reflected by the reflector 2 and then irradiated onto the second cuvette 3-2 through the second light-transmitting hole 12-2;

[0055] The cover 4 is arranged on the top of the detection box 10, so that the detection box becomes a dark room; a mobile phone camera shooting hole 8 is provided on the side wall of the detection box 10 corresponding to the middle position of the first cuvette 3-1 and the second cuvette 3-2; a smart phone fixing groove 7 for placing a smart phone is also provided on the side wall of the detection box 10 where the mobile phone camera shooting hole 8 is located. The smart phone is placed in the smart phone fixing groove 7, and the camera is aimed at the mobile phone camera shooting hole 8 to take pictures of the sample area.

[0056] The detection box of the present invention is a dark box, the position of the light source is fixed by a laser pen fixing tube, and then a light source reflector, a beam splitter and a reflector are arranged to split the laser into two beams with similar power, and the two beams are respectively irradiated into a first cuvette and a second cuvette, so that the two emit light synchronously, and then the two are photographed on the same photo by a mobile phone, which is convenient for subsequent analysis. The internal components of the device of the present invention are simple, without any complicated operations, and easy to assemble.

[0057] Preferably, a support frame 15 is provided below the laser pen fixing tube 9 for supporting the laser pen fixing tube 9; during use, the laser pen 14 is inserted into the laser pen fixing tube 9, and the laser emitted by the laser pen 14 passes through the incident hole 13 and irradiates the light source reflector 5.

[0058] Furthermore, two sample slots 17 are provided at the bottom of the detection box 10, namely a first sample slot 17-1 and a second sample slot 17-2. The first sample slot 17-1 is used to fix the first cuvette 3-1, and the second sample slot 17-2 is used to fix the second cuvette 3-2; it is convenient to fix the position of the cuvette, and the liquid height in the cuvette 3 is higher than the position of the light-transmitting hole 12, thereby ensuring the accuracy of the test results.

[0059] Furthermore, three positioning posts 16 are fixed at the bottom of the detection box 10, namely the first positioning post 16-1, the second positioning post 16-2 and the third positioning post 16-3, and the top of the positioning post 16 is provided with a thread; the beam splitter 1 is fixed by the beam splitter optical adjustment mirror frame 18, the reflector 2 is fixed by the reflector optical adjustment mirror frame 19, and the light source reflector 5 is fixed by the light source reflector frame 6; the bottom of the beam splitter optical adjustment mirror frame 18, the reflector optical adjustment mirror frame 19 and the light source reflector frame 6 are all provided with internal threads, which cooperate with the top threads of the positioning posts 16, and the beam splitter optical adjustment mirror frame 18, the reflector optical adjustment mirror frame 19 and the light source reflector frame 6 are respectively fixed on the first positioning post 16-1, the second positioning post 16-2 and the third positioning post 16-3; it is convenient to determine the fixed position of the optical lens during on-site installation. After the light source reflector, beam splitter and reflector are installed, the focal position height of the lens is consistent with the incident height of the laser pen, thereby ensuring the accuracy of the test results.

[0060] Example 2

[0061] A method for detecting protein in water based on a smartphone, comprising:

[0062] Step 1: Prepare bovine serum albumin standard solutions with concentrations of 128ug / L, 144ug / L, 160ug / L, 176ug / L, 192ug / L, 208ug / L, 224ug / L, and 240ug / L

[0063] Step 2: Take 2.5mL of 128ug / L bovine serum albumin standard solution, then add 500uL of Coomassie Brilliant Blue G250 solution (100mg / L), dilute to 5ml, and let stand at room temperature for 5 minutes to stabilize the color;

[0064] Step 3: Add 3 mL of the dyed protein solution to a 5 mL centrifuge tube, place it in the portable detection device of Example 1, use distilled water as a reference, turn on the laser pen of the device, and then take a picture. Figure 6 As shown, each group is repeated 3 times; in the portable detection device of Example 1, the wavelength of the laser emitted by the laser pen is 532nm;

[0065] Step 4: Cut out the effective area of ​​the photograph (the effective excitation area is the light column area formed by the laser beam passing through the solution in the cuvette, and ensure that the reference and experimental group areas are the same size), and obtain the R, G, and B values ​​of the corresponding areas of the sample solution and the reference solution respectively. Specifically: cut out the effective area picture, save it in the specified folder, and use Matlab software to write the following program:

[0066] I=imread('file location\image name.jpg','jpg');

[0067] RGB_mean=mean(mean(I));

[0068] R_mean=RGB_mean(:,:,1);

[0069] G_mean=RGB_mean(:,:,2);

[0070] B_mean=RGB_mean(:,:,3);

[0071] By running the above program, the average RGB value calculation of each valid area image is completed, that is, the process of converting optical signals into electrical signals and finally into digital signals is completed. The specific data is shown in Table 2;

[0072] Then calculate the A value according to formula (I), see Table 3;

[0073] (I);

[0074] Step 5: According to steps 2-4, take pictures of the mixed solutions of protein standard solution and dye solution with different concentrations (144ug / L, 160ug / L, 176ug / L, 192ug / L, 208ug / L, 224ug / L, 240ug / L) in sequence, intercept the corresponding R, G, B values ​​of each effective area, and calculate the A value in each picture; the results are shown in Table 2-3;

[0075] Table 2

[0076]

[0077] Table 3

[0078]

[0079] A standard working curve is established with protein concentration as the horizontal axis and A as the vertical axis, such as Figure 7 ;

[0080] Step 6: Collect the water sample to be tested, filter it through a 0.45μm pore size filter syringe, and then use hydrochloric acid or sodium hydroxide solution to adjust the pH of the solution to be tested to neutral, add 500ul of Coomassie Brilliant Blue G250 solution to 2.5mL of the solution to be tested, and let it stand for 5min; add 3mL of the post-reaction solution to the cuvette, put it into the sample tank of the device, and take 3mL of distilled water and add it to the reference tank; take a photo with a smartphone, substitute the photo into the computer program for analysis, extract the RGB value, and then calculate the corresponding A as 0.19, and combine the standard working curve to convert the protein concentration of the water sample to be tested to 152ug / L.

[0081] To verify the beneficial effects of the method of the present invention, the inventors also conducted the following experiments.

[0082] 1. Feasibility evaluation

[0083] 0.5 mL of Coomassie Brilliant Blue G250 solution was added to 2.5 mL of bovine serum albumin standard solutions with concentrations of 128 ug / L, 144 ug / L, 160 ug / L, 176 ug / L, 192 ug / L, 208 ug / L, 224 ug / L, and 240 ug / L, and the volume was adjusted to 5 ml, and the solution was allowed to stand at room temperature for 5 minutes to stabilize the color. The standard solutions were detected using a standard spectrophotometer and the equipment of Example 1 of the present invention, and a standard working curve was established according to the detection, as shown in FIG. Figure 7 The R² of the standard working curve established by the standard spectrophotometer is 0.9953, and the R² of the standard working curve established by the method of the present invention is 0.9854, which has high accuracy.

[0084] 3. Selection of effective area

[0085] Since the determination of protein is obtained indirectly by photographing the cuvette of the device in Example 1 with a smartphone, the selection of the effective area is crucial. Figure 8 As shown, the captured image captures the entire position of the cuvette and is then divided into two areas for evaluation: the light column area (the light column area formed by the laser beam shining through the solution in the cuvette) and the surrounding area (the area below the liquid surface in the cuvette excluding the light column area).

[0086] Add 0.5 mL of Coomassie Brilliant Blue G250 solution to 2.5 mL of bovine serum albumin standard solution with concentrations of 128 ug / L, 144 ug / L, 160 ug / L, 176 ug / L, 192 ug / L, 208 ug / L, 224 ug / L, and 240 ug / L, and adjust the volume to 5 ml. Let it stand at room temperature for 5 minutes to stabilize the color. Take 3 mL of the stained protein solution and take a photo with the device of Example 1, where the reference is 3 mL of distilled water. Calculate the relevant A values ​​of the two regions, establish the relationship curve between concentration and A value, and the working curve of the light column region is shown in Figure 7 , surrounding areas such as Fig. 9 The light column area is used as the effective area, and the obtained standard curve has a good linear relationship, but the related data of the surrounding area have no obvious linear relationship. In summary, it is reasonable to select the light column area as the effective area for subsequent determination.

[0087] 4. Selection of RGB channels

[0088] In Example 2, 3 mL of a mixed solution of a bovine serum albumin solution and a Coomassie Brilliant Blue G-250 solution with a concentration of 128, 144, 160, 176, 192, 208, 224, and 240 ug / L was poured into a cuvette in sequence and placed in the left sample pool of a portable detection device based on a smartphone; and 3 mL of distilled water was selected as a reference in the right sample pool. Each concentration was measured three times, three photos were taken, and the effective area was intercepted and the RGB average value was obtained, as shown in Table 2.

[0089] As can be seen from Table 2, since the R value of each photo has almost no change, the obtained RGB value is matched with the corresponding reference RGB value one by one to find and Then, the standard working curve of concentration and A value was established. The results are shown in Table 4. Figure 7 and Fig.10 .

[0090] Table 4

[0091]

[0092] Depend on Fig.10 It can be seen that there is a certain linear relationship between the G ratio of protein solutions of different concentrations, but there is no obvious linear relationship with the R and B ratios. Therefore, when the portable detection device based on smartphones is used to measure proteins, the G channel can be used as the detection channel and linearity can be established. In addition, the linear equation of the linear curve established by the G channel is: , R² = 0.9854. This means that establishing a linear curve of RhB through the G channel will be more sensitive and accurate.

[0093] 6. Accuracy evaluation

[0094] Water samples were collected from rivers in and around the school and from other places. A total of 6 water samples were collected and measured using a standard spectrophotometer and the equipment in Example 1, respectively. Each sample was measured three times. Figure 7 The final result is converted into a linear fitting curve. Figure 7 The method of converting the final turbidity using the linear fitting curve is recorded as the SPSD measurement result, as shown in Table 5.

[0095] Table 5

[0096]

[0097] As shown in Table 5, for the same water sample, the difference between the test results of the standard spectrophotometer and the SPSD test results of the present invention is not much. The results of the two tests on the same water sample are compared, as shown in Fig.11 As shown. Fig.11It can be seen that the ratio of the turbidity result of the water sample measured by the equipment in Example 1 to the result measured by the turbidity meter is controlled within 0.93-1.10, which is close to 1.000, indicating that the difference between the two measurement results is small, confirming that the result of measuring water turbidity with the assistance of a portable detection device assisted by a smartphone is reliable.

[0098] In summary, the present invention uses a portable detection device to perform simple photo processing, and the corresponding protein concentration can be obtained by calculating the A value; the device of the present invention is simple, can realize on-site detection of water samples, and has high detection accuracy.

[0099] The above is a preferred embodiment of the present invention. For ordinary technicians in this technical field, making several improvements and modifications without departing from the principles of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A method for detecting protein in water based on a smartphone, characterized in that: include: Step 1: Prepare protein standard solution; Step 2: Mix the protein standard solution with the dye and react at room temperature until the color is stable; Step 3: Add the protein solution stained in step 2 as the sample solution into the portable detection device, use distilled water as a reference, turn on the laser pen of the portable detection device, and then take relevant photos using a smartphone; Step 4: Cut out the effective area of ​​the photograph, and obtain the R, G, and B values ​​of the corresponding areas of the sample solution and the reference solution, and then calculate the A value according to formula (I); （I）； Step 5: Take photos of the mixed solutions of protein standard solutions and dye solutions with different concentrations in sequence, intercept the effective areas of each solution to identify the corresponding R, G, and B values, calculate the A value in each picture, and establish a standard working curve with protein concentration as the horizontal axis and A as the vertical axis; Step 6: After the water sample to be tested is pretreated, the corresponding A is determined by analogy with the above steps S3-S4, and the protein concentration of the water sample to be tested is calculated in combination with the standard working curve.

2. The detection method according to claim 1, characterized in that: In step 1, the protein is bovine serum albumin (BSA).

3. The detection method according to claim 2, characterized in that: The step 1 specifically includes: preparing protein standard solutions with concentrations of 128ug / L, 144ug / L, 160ug / L, 176ug / L, 192ug / L, 208ug / L, 224ug / L, and 240ug / L.

4. The detection method according to claim 2, characterized in that: The step 2 is specifically as follows: 2 mL of the protein standard solution is mixed with 2 mL of Coomassie brilliant blue dye, and reacted at room temperature for 5-30 minutes to stabilize the color.

5. The detection method according to claim 1, characterized in that: The step 3 is specifically as follows: 3 mL of the dyed protein solution is added into a 5 mL cuvette, which is placed into a portable detection device, distilled water is used as a reference, the laser pen of the device is turned on, and then pictures are taken, and each group is repeated 3 times.

6. The detection method according to claim 5, characterized in that: The laser pen emits a laser with a wavelength of 500-550 nm.

7. The detection method according to claim 1, characterized in that: In the step 4, the image is processed by Matlab software; the effective area is the light column area formed by the laser beam passing through the solution in the cuvette.

8. The detection method according to claim 1, characterized in that: In step 6, a water sample to be tested is collected, filtered through a 0.45 μm pore size filter syringe, and then the pH of the solution to be tested is adjusted to neutral using hydrochloric acid or sodium hydroxide solution before testing.

9. The detection method according to claim 1, characterized in that: In step 3, the portable detection device includes a laser pen, a light source reflector, a beam splitter, a reflector, a cuvette, a cover, a laser pen fixing tube and a detection box; The detection box is provided with a partition plate for dividing the detection box into a light mirror area and a sample area; the partition plate is provided with light-transmitting holes, and the light-transmitting holes include a first light-transmitting hole and a second light-transmitting hole; The optical mirror area is used to place the light source reflector, beam splitter and reflector. The laser emitted by the laser pen irradiates the light source reflector, and the light is reflected to the beam splitter through the light source reflector. The sample area is used to place the cuvette, and the cuvette includes a first cuvette and a second cuvette. In the optical mirror area, an incident hole is provided on the side wall of the detection box, and the laser pen fixing tube is used to fix the laser pen on the side wall of the detection box. The laser emitted by the laser pen is irradiated onto the light source reflector through the incident hole, and then reflected onto the beam splitter, and the beam splitter splits the laser into two beams of laser light with the same power and parallel to each other; one beam of laser light is irradiated onto the first cuvette through the first light-transmitting hole, and the other beam of laser light is irradiated onto the reflector, and then reflected by the reflector and irradiated onto the second cuvette through the second light-transmitting hole; The cover is arranged on the top of the detection box so that the detection box forms a dark room; A mobile phone camera shooting hole is provided on the side wall of the detection box corresponding to the middle position between the first cuvette and the second cuvette; a smartphone fixing groove for placing a smartphone is also provided on the side wall of the detection box where the mobile phone camera shooting hole is located, and the smartphone is placed in the smartphone fixing groove, and the camera is aimed at the mobile phone camera shooting hole to take pictures of the sample area.

10. The detection method according to claim 1, characterized in that: A support frame is provided below the laser pen fixing tube for supporting the laser pen fixing tube; The bottom of the detection box is provided with two sample slots, namely a first sample slot and a second sample slot, wherein the first sample slot is used to fix the first cuvette, and the second sample slot is used to fix the second cuvette; Three positioning posts are fixed on the bottom of the detection box, namely the first positioning post, the second positioning post and the third positioning post, and threads are provided on the tops of the positioning posts; the beam splitter is fixed by the beam splitter optical adjustment frame, the reflector is fixed by the reflector optical adjustment frame, and the light source reflector is fixed by the light source reflector frame, and the bottoms of the beam splitter optical adjustment frame, the reflector optical adjustment frame and the light source reflector frame are all provided with internal threads, which cooperate with the threads on the tops of the positioning posts, and the beam splitter optical adjustment frame, the reflector optical adjustment frame and the light source reflector frame are respectively fixed on the first positioning post, the second positioning post and the third positioning post.

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