Detection method and application of Tonxiaokang concentration and Tonxiaokang drug concentration detection device

Abstract

The invention relates to a method for detecting the concentration of Tongxekang, application and a device for detecting the concentration of Tongxekang drugs. According to the detection method provided by the invention, the concentration of the Tongxekang can be rapidly detected at a lower cost, the detection means is simple, the technical requirements on operators are lower, and the method is easier to popularize in a large range.

Description

Technical Field

[0001] The present invention relates to the field of piroxicam drug residue detection, and in particular to a piroxicam concentration detection method, application, and piroxicam drug concentration detection device. Background Art

[0002] Mastitis is a common disease in dairy cows and a major factor in reducing milk production. Tenoxicam and other piroxicam-like drugs, as nonsteroidal anti-inflammatory drugs (NSAIDs), are widely used to treat mastitis in dairy cows. However, the overuse of piroxicam-like drugs has also led to food safety concerns. Long-term human consumption can cause headaches, dizziness, stomach ulcers, and other problems. Therefore, detecting piroxicam-like drug residues in food is crucial for food safety. However, existing methods for detecting piroxicam-like drug residues are costly and complex. Summary of the Invention

[0003] Based on this, it is necessary to provide a method, application, and device for detecting the concentration of piroxicam-type drugs to address the problems of high cost and complex operation of detecting piroxicam-type drug residues.

[0004] The technical solution provided by the present invention is: A method for detecting the concentration of piroxicam comprises the following steps: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with 374 nm excitation light, and the 425 nm fluorescence intensity emitted by the carbon quantum dots is detected as i 425 ; Irradiate the carbon quantum dots with 470nm excitation light, and detect the 533nm fluorescence intensity emitted by the carbon quantum dots as i 533 ; After the carbon quantum dots were mixed with the solution to be tested, the carbon quantum dots were irradiated with 374 nm excitation light, and the fluorescence intensity at 425 nm emitted by the carbon quantum dots was detected as I. 425 ; Irradiate the carbon quantum dots with 470nm excitation light, and detect the 533nm fluorescence intensity emitted by the carbon quantum dots as 1 533 ; Based on i 425 / i 533 and I 425 / I 533 Determine the concentration of piroxicam in the test solution; The preparation method of the carbon quantum dots comprises the following steps: dissolving meta-naphthalene diol and tris(hydroxymethyl)aminomethane in a solvent, and then heating the solvent in a reactor to obtain the carbon quantum dots.

[0005] A method for preparing carbon quantum dots comprising the following steps: dissolving metanaphthalene diol and tris(hydroxymethyl)aminomethane in a solvent, and then heating the mixture in a reactor to obtain the carbon quantum dots.

[0006] Application of hierarchical cluster analysis in the detection of pyrimethamine-like drugs.

[0007] Application of linear discriminant analysis in the detection of pyrimethamine-like drugs.

[0008] A device for detecting the concentration of a piroxicam-type drug, comprising: The first light source has a wavelength of 374 nm and is used to illuminate the carbon quantum dots; A second light source having a wavelength of 470 nm for irradiating the carbon quantum dots; and A photographing device for photographing carbon quantum dots.

[0009] A method for detecting the concentration of piroxicam-type drugs, based on a piroxicam-type drug concentration detection device, comprises the following steps: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a first light source, and then the carbon quantum dots are photographed by a photographing device to obtain a first photograph, and then the average B value B0 of all pixels in the first photograph is obtained; Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a second light source, and then the camera captures the carbon quantum dots to obtain a second photograph, and then the average value G0 of the G values ​​of all pixels in the second photograph is obtained; After the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a first light source, and then the carbon quantum dots are photographed by a photographing device to obtain a first photograph, and then the average value b of the B values ​​of all pixels in the first photograph is obtained; After the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a second light source, and then the camera photographs the carbon quantum dots to obtain a second photograph, and then the average value g of the G value of all pixels in the second photograph is obtained; Determine the concentration of the piroxicam-type drug in the test solution based on B0 / G0 and b / g; The preparation method of the carbon quantum dots comprises the following steps: dissolving meta-naphthalene diol and tris(hydroxymethyl)aminomethane in a solvent, and then heating the solvent in a reactor to obtain the carbon quantum dots.

[0010] The beneficial effects of the present invention are: The detection method provided by the present invention can quickly detect the concentration of piroxicam at a low cost, has simple detection means, has low technical requirements for operators, and is easier to popularize on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 TEM image of carbon quantum dots in Example 1 of the present invention; Figure 2 This is a particle size distribution diagram of carbon quantum dots in Example 1 of the present invention; Figure 3 This is the XRD pattern of the carbon quantum dots in Example 1 of the present invention; Figure 4 This is a Raman spectrum of carbon quantum dots in Example 1 of the present invention; Figure 5 This is the FT-IR spectrum of the carbon quantum dots in Example 1 of the present invention; Figure 6 This is the full XPS spectrum of the carbon quantum dots in Example 1 of the present invention; Figure 7 This is a high-resolution XPS spectrum of C 1s of the carbon quantum dots in Example 1 of the present invention; Figure 8 This is the N 1s high-resolution XPS spectrum of the carbon quantum dots in Example 1 of the present invention; Figure 9 This is the O1s high-resolution XPS spectrum of the carbon quantum dots in Example 1 of the present invention; Figure 10 PL spectra of the carbon quantum dots in Example 1 of the present invention under excitation light of different wavelengths; Figure 11 This is the EEM spectrum of the carbon quantum dots in Example 1 of the present invention; Figure 12 The UV-vis absorption spectrum, PL spectrum and PLE spectrum of the carbon quantum dots in Example 1 of the present invention are shown; Figure 13 is the relative fluorescence intensity of the carbon quantum dots in Example 1 of the present invention in NaCl solutions of different concentrations; Figure 14 is the relative fluorescence intensity of the carbon quantum dots after being irradiated with ultraviolet light for different times in Example 1 of the present invention; Figure 15 is the relative fluorescence intensity of the carbon quantum dots after exposure to natural light for different periods of time in Example 1 of the present invention; Figure 16 I after mixing different substances with carbon quanta in Example 2 of the present invention 425 / I 533 Numerical bar graph; Figure 17 The carbon quantum mixed with TNX in Example 2 of the present invention at different temperatures 425 / I 533 Numerical bar graph; Figure 18 The carbon quantum in Example 2 of the present invention is mixed with different types of thiazolinone drugs. 425 / I 533 Curve of value changing with time; Figure 19 The carbon quantum obtained in Example 2 of the present invention is mixed with different types of thiazolinone drugs under different pH conditions. 425 / I 533 Numerical bar graph; Figure 20 PL spectra of carbon quanta mixed with different concentrations of TNX in Example 2 of the present invention; Figure 21 For Example 2 of the present invention,425 / I 533 and the relationship between the concentration of TNX mixed in the carbon quantum; Figure 22 For Example 2 of the present invention, 425 / I 533 and the relationship between the LNX concentration mixed in the carbon quantum; Figure 23 For Example 2 of the present invention, 425 / I 533 and the relationship between the concentration of PRX mixed in carbon quantum; Figure 24 For Example 2 of the present invention, 425 / I 533 and the relationship between the concentration of MLX mixed in the carbon quantum; Figure 25 The UV-vis absorption spectrum of the carbon quantum dots in Example 2 of the present invention, the UV-vis absorption spectrum of TNX, the theoretical UV-vis absorption spectrum after the carbon quantum dots and TNX are mixed, and the actual UV-vis absorption spectrum after the carbon quantum dots and TNX are mixed; Figure 26 The UV-vis absorption spectrum of TNX, the PL spectrum and the PLE spectrum of carbon quantum dots in Example 2 of the present invention are shown; Figure 27 : is the fluorescence lifetime decay curve of the carbon quantum dots before and after mixing with TNX in Example 2 of the present invention; Figure 28 This is a schematic diagram of the fluorescence intensity corresponding to different emission wavelengths when the carbon quantum dots are mixed with different types of piroxicam-type drugs in Example 3 of the present invention and illuminated by excitation light of different wavelengths; Figure 29a The HCA test results in Example 3 of the present invention are Figure 1 ; Figure 29b The LDA test results in Example 3 of the present invention are Figure 1 ; Figure 30a The HCA test results in Example 3 of the present invention are Figure 2 ; Figure 30b The LDA test results in Example 3 of the present invention are Figure 2 ; Figure 31a The HCA test results in Example 3 of the present invention are Figure 3 ; Figure 31b The LDA test results in Example 3 of the present invention are Figure 3 ; Figure 32a The HCA test results in Example 3 of the present invention are Figure 4 ; Figure 32b The LDA test results in Example 3 of the present invention are Figure 4 ; Figure 33a The HCA test results in Example 3 of the present invention are Figure 5 ; Figure 33b The LDA test results in Example 3 of the present invention are Figure 5 ; Figure 34a The HCA test results in Example 3 of the present invention are Figure 6 ; Figure 34b The LDA test results in Example 3 of the present invention are Figure 6 ; Figure 35a The HCA test results in Example 3 of the present invention are Figure 7 ; Figure 35b The LDA test results in Example 3 of the present invention are Figure 7 ; Figure 36a The HCA test results in Example 3 of the present invention are Figure 8 ; Figure 36b The LDA test results in Example 3 of the present invention are Figure 8 ; Figure 37 : is the relationship curve between the concentration of B / G and TNX mixed in carbon quantum dots in Example 4 of the present invention; Figure 38 : is the relationship curve between B / G and the LNX concentration mixed in the carbon quantum dots in Example 4 of the present invention; Figure 39 : is the relationship curve between the concentration of PRX mixed in B / G and carbon quantum dots in Example 4 of the present invention; Figure 40 4 is a relationship curve between B / G and the concentration of MLX mixed in carbon quantum dots in Example 4 of the present invention. DETAILED DESCRIPTION

[0012] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0013] Example 1:

[0014] This embodiment provides a method for preparing carbon quantum dots, comprising the following steps: dissolving 1 mmol of naphthoresorcinol and 1 mmol of tris (hydroxymethyl)aminomethane in 20 ml of ethanol, ultrasonically treating for 15 minutes, then transferring to a reactor and heating at 160°C for 6 hours. After the reaction is completed and cooled to room temperature, filtering is performed using a filter with a pore diameter of 0.22 μm, and then dialyzing the filtrate using a dialysis tube with a molecular weight of 500 Da for 24 hours, and then freeze-drying to obtain the carbon quantum dots. The morphological characteristics of the carbon quantum dots are as follows: Figure 1 As shown in the figure, it is not difficult to see that the carbon quantum dots do not aggregate significantly but are in a uniformly dispersed state, and their lattice spacing is 0.21nm, which matches the (100) plane of graphite carbon very well. Figure 3The peak of the XRD pattern appears at 25.9°, which matches the lattice spacing of the (002) plane of graphite carbon. Figure 4 The D peak appears at 1376 cm -1 The G peak appears at 1569cm -1 At the same time, the intensity ratio of the two is 0.76, showing a disordered sp 2 The properties of carbon prove the existence of graphite structure in the carbon quantum dots. Figure 2 As shown, the particle size distribution of the carbon quantum dots in this embodiment is between 3-7 nm, and the average particle size is approximately 4.5 nm.

[0015] The chemical structure of the carbon quantum dots is characterized as follows Figure 5-Figure 9 For details, see Figure 5 The carbon quantum dots are at 1067 cm -1 、1476cm -1 、1595cm -1 、1719cm -1 The stretching vibration peaks at 2900 cm-1 correspond to CN, CC, C=O, and C=N, respectively. -1 and 3400cm -1 The absorption band between them corresponds to the stretching vibration of -NH2 / -OH. Figure 6 This indicates that the carbon quantum dots contain 56.26% C, 14.23% N, and 29.51% O. Figure 7-Figure 9 The peak corresponding to C=C appears at 283.8eV, the peak corresponding to CN / CO appears at 285.6eV, the peak corresponding to C=N / C=O appears at 288.6eV, the peak corresponding to pyridine N appears at 397.6eV, the peak corresponding to amino N appears at 399.8eV, the peak corresponding to CO appears at 533.8eV, and the peak corresponding to C=O appears at 531.5eV. Figure 5-Figure 9 Characterization shows that the chemical formula of the carbon quantum dots in this embodiment is as follows: .

[0016] The fluorescence properties of the carbon quantum dots are as follows Figure 10-12 First see Figure 10 When the excitation light irradiates the carbon quantum dots and the wavelength of the excitation light gradually increases from 340nm to 500nm, the emission wavelength of the carbon quantum dots and the fluorescence intensity corresponding to the emission wavelength gradually change, which proves that there is a strong correlation between the excitation wavelength and the emission wavelength of the carbon quantum dots. Figure 11It can be clearly seen that the carbon quantum dots have two fluorescence emission centers, the excitation wavelengths corresponding to the two fluorescence emission centers are 374nm and 470nm, and the corresponding emission wavelengths are 425nm and 533nm, respectively. Figure 12 As shown in the UV-vis absorption spectrum of the carbon quantum dots, there is an absorption peak at 206 nm, which corresponds to the π-π bond of C=C in the benzene ring. * There is also an absorption peak at 283nm, which corresponds to the n-π transition of C=O. * There is also an absorption peak at 508nm, which corresponds to the molecular state transition on the surface of the carbon quantum dots. It is particularly noteworthy that the UV-vis absorption spectrum only slightly overlaps with the PL spectrum and PLE spectrum, indicating that the self-absorption effect of the carbon quantum dots is not strong. It can be guessed that the carbon quantum dots have a high fluorescence quantum yield. Further tests were carried out using quinine sulfate and rhodamine 6G as standard substances. The fluorescence quantum yields of the carbon quantum dots in alcohol were 57% and 42%, respectively, confirming the above speculation. Figure 12 As shown in the middle illustration, the carbon quantum dots are light brown in sunlight, blue in 374nm excitation light, and green in 470nm excitation light. The fluorescence stability test results of the carbon quantum dots are as follows. Figure 13 Even in the presence of 2.1M NaCl, the relative fluorescence intensity of the carbon quantum dots only decreases slightly, proving that the carbon quantum dots have good salt tolerance. Figure 14 and Figure 15 After 24 hours of ultraviolet light irradiation, the relative fluorescence intensity of the carbon quantum dots decreased only slightly. After 30 days of sunlight irradiation, the relative fluorescence intensity of the carbon quantum dots also decreased only slightly, proving that the carbon quantum dots have good light resistance.

[0017] Example 2:

[0018] Based on Example 1, this embodiment further provides an application of the carbon quantum dots in the detection of piroxicam drugs. The carbon quantum dots are irradiated with 374 nm excitation light, and the 425 nm fluorescence intensity emitted by the carbon quantum dots is 1 425 The carbon quantum dots were irradiated with 470nm excitation light, and the 533nm fluorescence intensity emitted by the carbon quantum dots was 1 533 In this embodiment, the gains corresponding to the 374nm excitation light and the 470nm excitation light are uniformly 550V.

[0019] Specific as Figure 16As shown, after the carbon quantum dots (carbon quantum dots concentration is 50 ng / μL) were mixed with different substances (concentration was uniformly 100 μM), only TNX (Tenoxicam), LNX (lornoxicam), PRX (piroxicam) and MLX (meloxicam) could induce I 425 / I 533 In other words, the carbon quantum dots can be used to detect the pain-related drugs. + , K + 、Ag + Mg 2+ 、Zn 2 + 、Co 2+ , Ca 2+ 、Ce 2+ , Pb 2+ 、Hg 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Al 3+ 、Cl - 、SO4 2- 、NO3 - 、SO3 2- 、glucose(Glu, glucose), ascorbic acid(AA, ascorbic acid), urea(urea), uric acid(UA, uric acid), L-asparagine(L-asp, L-asparagine), L-serine(L-ser, L-serine), L-tryptophan(L-try, L-tryptophan), L-proline(L-pro, L-proline), L-alanine(L-ala, L-alanine), L-cysteine(L-cys, L-cysteine), D-alanine(D-ala, D-alanine) cannot make I 425 / I 533 Obvious changes were produced, proving the specificity of the carbon quantum dots in detecting piroxicam-type drugs.

[0020] This example further explores the detection conditions of the carbon quantum dots for piroxicam. Figure 17-Figure 19 First, after the carbon quantum dots and TNX are mixed, in the temperature window range of 10℃-70℃, I 425 / I 533 There is almost no change, indicating that the carbon quantum dots have a wide detection temperature window for piroxicam. 425 / I 533 After about 4 minutes, the carbon quantum dots and LNX were mixed and the 425 / I 533 After about 4 minutes, the carbon quantum dots and PRX were mixed and the 425 / I 533 After about 3 minutes, the carbon quantum dots and MLX were mixed and the 425 / I 533 It stabilizes after about 5 minutes, which shows that when using the carbon quantum dots to detect pain-like drugs, it is necessary to wait for 5 minutes. 425 / I 533 There was almost no change, indicating that the carbon quantum dots have a wide detection pH window for piroxicam. Based on the above test analysis, the experimental conditions for subsequent carbon quantum dots in this example were locked at room temperature, reaction time of 5 minutes, and pH = 7.

[0021] Take TNX as an example, Figure 20 As shown, as the concentration of TNX gradually increased to 250 μM, I 425 Rapidly decrease, I 533 The decrease is only a small amount, which is almost negligible. In other words, at the same TNX concentration, I 425 and I 533 Based on this characteristic, the carbon quantum dots allow the use of 425 / I 533 Quantitative detection of TNX concentration. Figure 21 , when the TNX concentration increased from 0μM to 80μM, I 425 / I 533 When the concentration of TNX increased from 80μM to 250μM, I 425 / I 533 There is only a small change, which shows that the carbon quantum dots are difficult to be used for quantitative detection of high concentration TNX, but can be used for quantitative detection of low concentration TNX. 425 / I 533 There is a good linear relationship between them, and the corresponding detection limit of TNX concentration is 42nM.

[0022] The carbon quantum dots exhibit similar characteristics when detecting LNX, PRX and MLX. Figure 22 As shown, after the carbon quantum dots were mixed with LNX, as the concentration of LNX increased from 0 μM to 150 μM, I 425 / I533 When the concentration of LNX increased from 150μM to 250μM, I 425 / I 533 There is almost no change, indicating that the carbon quantum dots are difficult to be used for quantitative detection of high concentration LNX, but can be used for quantitative detection of low concentration LNX. 425 / I 533 There is a good linear relationship between them, and the corresponding detection limit of LNX concentration is 78nM. Figure 23 As shown, after the carbon quantum dots were mixed with PRX, as the PRX concentration increased from 0 μM to 70 μM, I 425 / I 533 When the PRX concentration increased from 70μM to 250μM, I 425 / I 533 There is almost no change, which shows that the carbon quantum dots are difficult to be used for quantitative detection of high concentration PRX, but can be used for quantitative detection of low concentration PRX. 425 / I 533 There is a good linear relationship between them, and the corresponding detection limit of PRX concentration is 33nM. Figure 24 As shown, after the carbon quantum dots were mixed with MLX, as the MLX concentration increased from 0 μM to 100 μM, I 425 / I 533 When the MLX concentration increased from 100 μM to 250 μM, I 425 / I 533 There is almost no change, which shows that the carbon quantum dots are difficult to be used for quantitative detection of high concentration MLX, but can be used for quantitative detection of low concentration MLX. 425 / I 533 There is a good linear relationship between them, and the corresponding detection limit of MLX concentration is 45nM.

[0023] Based on the above results, this embodiment provides a method for detecting the concentration of piroxicam, comprising the following steps: Step 101: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with 374 nm excitation light, and the 425 nm fluorescence intensity emitted by the carbon quantum dots is detected as i 425 ; Irradiate the carbon quantum dots with 470nm excitation light, and detect the 533nm fluorescence intensity emitted by the carbon quantum dots as i 533 ; Step 102: After the carbon quantum dots are mixed with the solution to be tested, the carbon quantum dots are irradiated with 374 nm excitation light, and the fluorescence intensity at 425 nm emitted by the carbon quantum dots is detected as I 425 ; Irradiate the carbon quantum dots with 470nm excitation light, and detect the 533nm fluorescence intensity emitted by the carbon quantum dots as 1 533 ; Step 103: Based on i 425 / i 533 and I 425 / I 533 Determine the concentration of piroxicam in the test solution.

[0024] This example further studies the reaction mechanism between the carbon quantum dots and piroxicam. Figure 25 As shown in FIG1 , taking TNX as an example, the actual UV-vis absorption spectrum of the carbon quantum dots and TNX after mixing does not produce any new absorption peaks compared to the theoretical UV-vis absorption spectrum of the carbon quantum dots and TNX after mixing, indicating that no new chemical groups are generated between the carbon quantum dots and TNX. The K value is further calculated according to the Benesi-Hildebrand equation to be 2.1×10 4 mol -1 , much greater than 10 3 mol -1 , indicating that the binding ability between carbon quantum dots and TNX is strong. In addition, the test shows that the zeta potential energy value of carbon quantum dots is 13.8mV, and the zeta potential energy value of TNX is -3.5mV, indicating that the polarity between carbon quantum dots and TNX is opposite, and there is a strong electrostatic attraction between the two. Therefore, the distance between carbon quantum dots and TNX is small, which helps to delocalize electrons in carbon quantum dots. In addition, due to the close energy levels between carbon quantum dots and TNX, part of the energy of the excited state of carbon quantum dots can be transferred to TNX, and the rest of the energy is transferred to TNX in a non-radiative form through dipole-dipole coupling. Figure 26 As shown in the figure, one of the PLE spectra (excitation wavelength 374nm) and one of the PL spectra (emission wavelength 425nm) of the carbon quantum dots have a large overlap with the UV-vis absorption spectrum of TNX, indicating that the blue fluorescence quenching mechanism of TNX on carbon quantum dots includes strong IFE (inner filter effect) and FERT (fluorescence resonance energy transfer). Figure 27 As shown in the figure, the average fluorescence lifetime of carbon quantum dots decreased from 3.05 ns to 2.91 ns before and after mixing with TNX, confirming the presence of FERT in the blue light quenching mechanism. Based on the change in average fluorescence lifetime, the efficiency of FERT in quenching blue fluorescence was calculated to be 4.6%.

[0025] Example 3:

[0026] See Figure 28 After mixing carbon quantum dots with a 40μM concentration of piroxicam, under 374nm excitation light, the emitted fluorescence intensity f1 at 400nm is shown in the histogram at F1, the emitted fluorescence intensity f2 at 425nm is shown in the histogram at F2, and the emitted fluorescence intensity f3 at 500nm is shown in the histogram at F3. Under 470nm excitation light, the emitted fluorescence intensity f4 at 508nm is shown in the histogram at F4, the emitted fluorescence intensity f5 at 533nm is shown in the histogram at F5, and the emitted fluorescence intensity f6 at 558nm is shown in the histogram at F6. It is not difficult to see that under 374nm excitation light, the effects of different piroxicam-like drugs on the fluorescence quenching of carbon quantum dots vary greatly, while under 470nm excitation light, the differences in the fluorescence quenching effects of different piroxicam-like drugs on carbon quantum dots are relatively small.

[0027] Based on this, this example first provides an application of hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA) in the detection of piroxicam-like drugs. Both applications can be used to determine the specific type of piroxicam and, in conjunction with the piroxicam concentration detection method provided in Example 2, achieve more accurate piroxicam detection. Both applications require the use of a first array consisting of f1, f2, f3, f4, f5, and f6.

[0028] Specific as Figure 29a As shown, when the total concentration of paxicon drugs is 20 μM, the first array corresponding to the case where all paxicon drugs are PRX (taking the case where all paxicon drugs are PRX as an example, its fluorescence spectrum was tested five times, so there are five first arrays corresponding to the case where all paxicon drugs are PRX. The following cases are similar and will not be repeated here), the first array corresponding to the case where all paxicon drugs are TNX, the first array corresponding to the case where all paxicon drugs are MLX, and the first array corresponding to the case where all paxicon drugs are LNX, a total of twenty first arrays are input into the clustering tree for classification. The classification results are set as PRX, TNX, MLX, and LNX, and the classification accuracy is 100% (each classification result corresponds to five first arrays). See Figure 29b LDA was performed on the 20 first-order data sets, with the classification results set as PRX, TNX, MLX, and LNX. The classification accuracy was 100%. This proves that both HCA and LDA can be used to distinguish between piroxicam-type drugs at low concentrations.

[0029] like Figure 30aAs shown in FIG, when the total concentration of the piroxicam drugs is 40 μM, the first array corresponding to when all the piroxicam drugs are PRX, the first array corresponding to when all the piroxicam drugs are TNX, the first array corresponding to when all the piroxicam drugs are MLX, and the first array corresponding to when all the piroxicam drugs are LNX, a total of 20 first arrays are input into the clustering tree for classification. The classification results are set as PRX, TNX, MLX, and LNX. The classification accuracy is also 100% (each classification result corresponds to five first arrays). Figure 30b ,LDA is performed on the above twenty first arrays, and the classification results are set as PRX, TNX, MLX, and LNX, and the classification accuracy is 100%.

[0030] like Figure 31a As shown in FIG, when the total concentration of the piroxicam drugs is 60 μM, the first array corresponding to the case where all the piroxicam drugs are PRX, the first array corresponding to the case where all the piroxicam drugs are TNX, the first array corresponding to the case where all the piroxicam drugs are MLX, and the first array corresponding to the case where all the piroxicam drugs are LNX, a total of 20 first arrays are input into the clustering tree for classification. The classification results are set as PRX, TNX, MLX, and LNX. The classification accuracy is still 100% (each classification result corresponds to five first arrays). Figure 31b ,LDA is performed on the above twenty first arrays, and the classification results are set as PRX, TNX, MLX, and LNX, and the classification accuracy is 100%.

[0031] like Figure 32a As shown, when the total concentration of the piroxicam drugs is 45 μM, the first array corresponding to the case where all the piroxicam drugs are TNX, the first array corresponding to the case where the piroxicam drugs are a mixture of 70% TNX and 30% MLX, the first array corresponding to the case where the piroxicam drugs are a mixture of 50% TNX and 50% MLX, the first array corresponding to the case where the piroxicam drugs are a mixture of 30% TNX and 70% MLX, and the first array corresponding to the case where all the piroxicam drugs are MLX, a total of 25 first arrays, are input into the cluster tree for classification. The classification results are set as 100% TNX, 70% TNX + 30% MLX, 50% TNX + 50% MLX, 30% TNX + 70% MLX, and 100% MLX, and the classification accuracy is 100% (each classification result corresponds to five first arrays). See. Figure 32bLDA was performed on the 25 first arrays, and the classification results were set as 100% TNX, 70% TNX + 30% MLX, 50% TNX + 50% MLX, 30% TNX + 70% MLX, and 100% MLX, with a classification accuracy of 100%. For example, 70% TNX means that the TNX concentration is 70% of the total concentration of the piroxicam-type drug, that is, 45 μM × 70%.

[0032] like Figure 33a As shown, when the total concentration of the piroxicam drugs is 45 μM, the first array corresponding to the case where all the piroxicam drugs are TNX, the first array corresponding to the case where the piroxicam drugs are a mixture of 70% TNX and 30% PRX, the first array corresponding to the case where the piroxicam drugs are a mixture of 30% TNX and 70% PRX, the first array corresponding to the case where the piroxicam drugs are a mixture of 50% TNX and 50% PRX, and the first array corresponding to the case where all the piroxicam drugs are PRX, a total of 25 first arrays, are input into the clustering tree for classification. The classification results are set as 100% TNX, 70% TNX + 30% PRX, 30% TNX + 70% PRX, 50% TNX + 50% PRX, and 100% PRX, and the classification accuracy is 100% (each classification result corresponds to five first arrays). See. Figure 33b , LDA was performed on the above 25 first arrays, and the classification results were set as 100% TNX, 70% TNX+30%PRX, 30% TNX+70%PRX, 50% TNX+50%PRX, and 100%PRX, and the classification accuracy was 100%.

[0033] like Figure 34a As shown, when the total concentration of the piroxicam-like drugs is 45 μM, the first array corresponding to the case where all the piroxicam-like drugs are TNX, the first array corresponding to the case where the piroxicam-like drugs are a mixture of 70% TNX and 30% LNX, the first array corresponding to the case where the piroxicam-like drugs are a mixture of 50% TNX and 50% LNX, the first array corresponding to the case where all the piroxicam-like drugs are LNX, and the first array corresponding to the case where the piroxicam-like drugs are a mixture of 30% TNX and 70% LNX, totaling 25 first arrays, are input into the cluster tree for classification. The classification results are set as 100% TNX, 70% TNX + 30% LNX, 50% TNX + 50% LNX, 100% LNX, and 30% TNX + 70% LNX, and the classification accuracy is 100% (each classification result corresponds to five first arrays). See. Figure 34b, LDA was performed on the above 25 first arrays, and the classification results were set as 100% TNX, 70% TNX+30% LNX, 50% TNX+50% LNX, 100% LNX, 30% TNX+70% LNX, and the classification accuracy was 100%.

[0034] like Figure 35a As shown, when the total concentration of the piroxicam drugs is 45 μM, the first array corresponding to the mixture of 50% MLX and 50% TNX of the piroxicam drugs, the first array corresponding to the mixture of 50% TNX and 50% LNX of the piroxicam drugs, the first array corresponding to the mixture of 50% PRX and 50% TNX of the piroxicam drugs, the first array corresponding to the mixture of 50% PRX and 50% LNX of the piroxicam drugs, the first array corresponding to the mixture of 50% MLX and 50% PRX of the piroxicam drugs, and the first array corresponding to the mixture of 50% LNX and 50% MLX of the piroxicam drugs are input into the clustering tree for classification, and the classification results are set as 50% MLX+50% TNX, 50% TNX+50%LNX, 50% PRX+50% TNX, 50% PRX+50% LNX, 50% MLX+50% PRX, 50% LNX+50% MLX, its classification accuracy is 100% (each classification result corresponds to five first arrays). Figure 35b , LDA was performed on the above thirty first arrays, and the classification results were set as 50% MLX+50% TNX, 50% TNX+50% LNX, 50% PRX+50% TNX, 50% PRX+50%LNX, 50% MLX+50% PRX, 50% LNX+50% MLX, and the classification accuracy was 100%.

[0035] like Figure 36aAs shown, when the total concentration of the piroxicam-like drugs is 45 μM, the first array corresponding to the mixture of MLX, PRX, and LNX (the concentration of each component is 15 μM), the first array corresponding to the mixture of TNX, PRX, and LNX (the concentration of each component is 15 μM), the first array corresponding to the mixture of TNX, MLX, and LNX (the concentration of each component is 15 μM), and the first array corresponding to the mixture of TNX, MLX, and PRX (the concentration of each component is 15 μM) are input into the clustering tree for classification. The classification results are set as MLX+PRX+LNX, TNX+PRX+LNX, TNX+MLX+LNX, and TNX+MLX+PRX, and the classification accuracy is 100% (each classification result corresponds to five first arrays). See Figure 36b , LDA is performed on the above twenty first arrays, and the classification results are set as MLX+PRX+LNX, TNX+PRX+LNX, TNX+MLX+LNX, TNX+MLX+PRX, and the classification accuracy is 100%.

[0036] Example 4:

[0037] This embodiment further provides a device for detecting the concentration of a piroxicam-type drug, comprising a first light source (with a wavelength of 374 nm), a second light source (with a wavelength of 470 nm), and a photographing device.

[0038] The carbon quantum dots are illuminated by a first light source, and then photographed by a camera to obtain a first photo. The carbon quantum dots are illuminated by a second light source, and then photographed by the camera to obtain a second photo. Accordingly, each pixel in the first and second photos has a corresponding RGB value (including R, G, and B values).

[0039] like Figure 37 As shown in Figure 2, when carbon quantum dots (1.5 mg / mL) and TNX are mixed, the ratio (B / G) between the average B value of all pixels in the first photo and the average G value of all pixels in the second photo first decreases with the increase of TNX concentration. Subsequently, when the TNX concentration is greater than 150 μM, B / G almost no longer changes with the increase of TNX concentration. Figure 21 Comparison revealed that B / G can quantitatively detect higher concentrations of TNX. Furthermore, within the TNX concentration range of 112 nM to 30 μM, a good linear relationship was maintained between B / G and TNX. Consequently, the lower limit of TNX detection using B / G is 112 nM.

[0040] like Figure 38As shown, after mixing carbon quantum dots (1.5 mg / mL) with LNX, the ratio (B / G) of the average B value of all pixels in the first image to the average G value of all pixels in the second image initially decreases with increasing LNX concentration. Subsequently, when the LNX concentration exceeds 150 μM, B / G hardly changes with increasing LNX concentration. A good linear relationship is maintained between B / G and LNX concentrations within the 241 nM-60 μM range, resulting in a lower limit of detection for LNX concentration using B / G of 241 nM.

[0041] like Figure 39 As shown in the figure, when carbon quantum dots (1.5 mg / mL) and PRX are mixed, the ratio B / G between the average B value of all pixels in the first photo and the average G value of all pixels in the second photo first decreases with the increase of PRX concentration. Subsequently, when the PRX concentration is greater than 150 μM, B / G almost no longer changes with the increase of PRX concentration. Figure 23 By comparison, it can be found that B / G can quantitatively detect higher concentrations of PRX. When the PRX concentration is within the range of 107nM-30μM, it can maintain a good linear relationship with B / G. Correspondingly, the lower limit of PRX detection using B / G is 107nM.

[0042] like Figure 40 As shown, after mixing carbon quantum dots (1.5 mg / mL) with MLX, the ratio (B / G) of the average B value of all pixels in the first image to the average G value of all pixels in the second image initially decreases with increasing MLX concentration. Subsequently, when the MLX concentration exceeds 100 μM, B / G hardly changes with increasing MLX concentration. A good linear relationship is maintained between B / G and MLX concentrations within the 152 nM-50 μM range, resulting in a lower limit of detection for MLX concentration using B / G of 152 nM.

[0043] Based on the above conclusions, this embodiment further provides a method for detecting the concentration of piroxicam-type drugs, comprising the following steps: Step 201: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a first light source, and then the camera captures the carbon quantum dots to obtain a first photograph, and then the average B0 of the B values ​​of all pixels in the first photograph is obtained; Step 202: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a second light source, and then the camera captures the carbon quantum dots to obtain a second photograph, and then the average value G0 of the G value of all pixels in the second photograph is obtained; Step 203: After the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a first light source, and then the camera captures the carbon quantum dots to obtain a first photograph, and then the average value b of the B values ​​of all pixels in the first photograph is obtained; Step 204: After the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a second light source, and then the camera captures the carbon quantum dots to obtain a second photograph, and then the average value g of the G value of all pixels in the second photograph is obtained; Step 205: Determine the concentration of the piroxicam-type drug in the test solution based on B0 / G0 and b / g.

[0044] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for detecting the concentration of piroxicam, characterized in that: The steps include: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with 374 nm excitation light, and the 425 nm fluorescence intensity emitted by the carbon quantum dots is detected as i 425 ; Irradiate the carbon quantum dots with 470nm excitation light, and detect the 533nm fluorescence intensity emitted by the carbon quantum dots as i 533 ; After the carbon quantum dots were mixed with the solution to be tested, the carbon quantum dots were irradiated with 374 nm excitation light, and the fluorescence intensity at 425 nm emitted by the carbon quantum dots was detected as I. 425 ; Irradiate the carbon quantum dots with 470nm excitation light, and detect the 533nm fluorescence intensity emitted by the carbon quantum dots as 1 533 ; Based on i 425 / i 533 and I 425 / I 533 Determine the concentration of piroxicam in the test solution; The preparation method of the carbon quantum dots comprises the following steps: dissolving meta-naphthalene diol and tris(hydroxymethyl)aminomethane in a solvent, and then heating the solvent in a reactor to obtain the carbon quantum dots.

2. An application of carbon quantum dots in the detection of piroxicam concentration, characterized in that: The preparation method of the carbon quantum dots comprises the following steps: dissolving meta-naphthalene diol and tris(hydroxymethyl)aminomethane in a solvent, and then heating the solvent in a reactor to obtain the carbon quantum dots.

3. Application of hierarchical cluster analysis in the detection of pyraclostrobin-type drugs.

4. Application of linear discriminant analysis in the detection of pyrimethamine-type drugs.

5. A device for detecting the concentration of piroxicam-type drugs, characterized in that: include: The first light source has a wavelength of 374 nm and is used to illuminate the carbon quantum dots; The second light source has a wavelength of 470 nm and is used to illuminate the carbon quantum dots; as well as A photographing device for photographing carbon quantum dots.

6. A method for detecting the concentration of piroxicam-type drugs, characterized in that: Based on the device for detecting the concentration of piroxicam-like drugs according to claim 5, the method for detecting the concentration of piroxicam-like drugs comprises the following steps: Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a first light source, and then the carbon quantum dots are photographed by a photographing device to obtain a first photograph, and then the average B value B0 of all pixels in the first photograph is obtained; Before the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a second light source, and then the camera captures the carbon quantum dots to obtain a second photograph, and then the average value G0 of the G values ​​of all pixels in the second photograph is obtained; After the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a first light source, and then the carbon quantum dots are photographed by a photographing device to obtain a first photograph, and then the average value b of the B values ​​of all pixels in the first photograph is obtained; After the carbon quantum dots are mixed with the test solution, the carbon quantum dots are irradiated with a second light source, and then the camera photographs the carbon quantum dots to obtain a second photograph, and then the average value g of the G value of all pixels in the second photograph is obtained; Determine the concentration of the piroxicam-type drug in the test solution based on B0 / G0 and b / g; The preparation method of the carbon quantum dots comprises the following steps: dissolving meta-naphthalene diol and tris(hydroxymethyl)aminomethane in a solvent, and then heating the solvent in a reactor to obtain the carbon quantum dots.

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