Catecholamine detection method, detection probe and detection sensor

Abstract

The present application discloses a method for detecting catecholamines, a detection probe, and a detection sensor. The detection method is to detect the fluorescence value of ferroferric oxide quantum dots at an excitation wavelength of 280 to 350 nm and / or the ultraviolet absorption value at a wavelength of 220 to 350 nm under the conditions of adding a buffer and a target analyte. The present technical solution has a fluorescence and ultraviolet dual signal detection mode, making the detection results more accurate and reliable. The present technical solution has the advantages of faster response speed, good selectivity, high sensitivity, and strong anti-interference ability. It has good application potential for detecting catecholamines in serum samples, and can semi-quantitatively and visually detect EP, NEP, and DA, and has great promotion and application value.

Description

Technical Field

[0001] The present application relates to the technical field of biological detection, and in particular to a detection method, a detection probe, and a detection sensor for catecholamines. Background Art

[0002] Since the 1970s, research has focused on semiconductor nanocrystals, which have since been applied in numerous fields. Quantum dots, due to their nanoscale size, possess many unique properties, such as optical and electrical properties. These unique optical and electrical properties have made them a rapidly developing research tool. Initially, researchers hoped to exploit the unique properties of quantum dots to create quantum computers, but significant breakthroughs remained. Subsequently, quantum dots were applied to biology, but significant success remained due to the difficulties in their preparation, stringent synthesis conditions, low fluorescence yield, and poor binding to biomolecules. Through continuous research, quantum dot synthesis methods have been optimized. Quantum dots synthesized in aqueous solutions are now not only applicable to various bioimaging labeling studies, but also hold great promise in life science research. Alloy quantum dots can be modified by adjusting the component content to alter their internal structure, thereby varying the wavelength of their fluorescence emission, thereby emitting different colors. Previous reports have shown that the fluorescence intensity and efficiency of alloy quantum dots are comparable to, or even exceeding, those of conventional quantum dots.

[0003] Dopamine, epinephrine, and norepinephrine are biological catecholamines. Numerous methods have been developed for the quantitative detection of catecholamines, including electrochemistry, chemiluminescence, high-performance liquid chromatography, and capillary electrophoresis. However, these methods all have drawbacks, including the expensive equipment required, complex procedures, and the use of highly toxic drugs.

[0004] Therefore, there is an urgent need to develop a rapid, simple, low-cost, highly sensitive and selective method to detect trace catecholamines in biological fluids. Summary of the Invention

[0005] In view of this, the present application provides a method, a detection probe, and a detection sensor for catecholamines, which can accurately and reliably detect catecholamines.

[0006] In a first aspect, the present application provides a method for detecting catecholamines, which detects the fluorescence value of ferroferric oxide quantum dots at an excitation wavelength of 280 to 350 nm and / or the ultraviolet absorption value at a wavelength of 220 to 350 nm under the conditions of adding a buffer and a target analyte.

[0007] Optionally, the XRD spectrum parameters of the ferroferric oxide quantum dots are:

[0008] Diffraction angle 2θ (°) 29.85° 35.39° 43.29° 49.19° 56.98° 62.88° Diffraction peak crystal plane (220) (331) (400) (420) (511) (440) .

[0009] Optionally, the XPS spectrum parameters of the ferroferric oxide quantum dots are:

[0010] Bond energy (ev) 282.47 533.81 712.56 Peak content (%) C1s peak 63.48 O1s peak 34.9 Fe2p peak 1.62 .

[0011] Optionally, the quantum yield of the ferroferric oxide quantum dots is 67-71%.

[0012] Optionally, the pH value of the addition condition corresponding to the target analyte is 8-14.

[0013] Optionally, the buffer is sodium hydroxide or BR buffer solution.

[0014] Optionally, the concentration of the ferroferric oxide quantum dots is 1 to 2 μg mL -1 The dosage concentration is defined as the ratio of the mass of the ferroferric oxide quantum dots to the volume of the liquid consisting of the buffer and the target analyte.

[0015] Optionally, the contact time between the ferroferric oxide quantum dots and the target object to be detected is 0.5 to 30 minutes.

[0016] In a second aspect, the present application provides a catecholamine detection probe having ferroferric oxide quantum dots.

[0017] In a third aspect, the present application provides a catecholamine detection sensor having ferroferric oxide quantum dots.

[0018] [Beneficial effects of this application]

[0019] (1) This technical solution has a dual-signal detection mode of fluorescence and ultraviolet, making the detection results more accurate and reliable;

[0020] (2) This technical solution has the advantages of fast response speed, good selectivity, high sensitivity and strong anti-interference ability, and has good application potential for detecting catecholamines in serum samples. In addition, it can semi-quantitatively detect EP, NEP and DA, which has great promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0022] Figure 1 This is a transmission electron microscope (TEM) spectrum of the Fe3O4 QDs disclosed in the examples of this application.

[0023] Figure 2This is the XRD pattern of the ferroferric oxide quantum dots disclosed in the examples of this application.

[0024] Figure 3 This is the XPS graph of the ferroferric oxide nanoparticles and ferroferric oxide quantum dots disclosed in the examples of this application.

[0025] Figure 4(a)-Figure 4(f) This is the XPS peak spectrum of the ferroferric oxide nanoparticles and ferroferric oxide quantum dots disclosed in the examples of this application.

[0026] Figure 5 The UV-visible absorption spectrum and fluorescence excitation and emission spectra of the ferroferric oxide quantum dots disclosed in the examples of this application;

[0027] The illustrations in this figure are photos taken under visible light (left) and 365nm ultraviolet light (right);

[0028] Figure 6 This is a relationship diagram of the effects of buffer solutions of different pH values ​​on the system disclosed in the examples of this application;

[0029] Figure 7 This is a diagram showing the mechanism of the catecholamine-base reaction disclosed in the examples of this application;

[0030] Figure 8(a) shows the UV-visible absorption spectra of EP and P-EP and the fluorescence excitation and emission spectra of Fe3O4QDs disclosed in the examples of this application; Figure 8(b) shows the UV absorption spectra of Fe3O4QDs, EP, P-EP, and Fe3O4QDs+P-EP; Figure 8(c) shows the fluorescence lifetime spectra of Fe3O4QDs and Fe3O4QDs+EP;

[0031] Figure 9 Synthesis of Fe3O4 QDs and mechanism of detection of catecholamines disclosed in the examples of this application;

[0032] Figure 10 This is a diagram showing the effects of different concentrations of Fe3O4 QDs on the system disclosed in the examples of this application;

[0033] Figure 11 This is a graph showing the relationship between the response time of the Fe3O4 quantum dot fluorescent probe to epinephrine disclosed in the examples of this application;

[0034] Figure 12 This is a diagram showing the selectivity of ferroferric oxide quantum dots to blood biomolecules disclosed in the examples of this application;

[0035] FIG13 shows the analytical performance of EP, NEP and DA disclosed in the examples of this application;

[0036] Among them, the fluorescence spectra of the fluorescence sensor at different concentrations of (a) EP, (b) NEP, (c) DA (inset: color under 365nm UV light); linear plots of F0 / F and corresponding (d) EP, (e) NEP, (f) DAd concentrations. (g) UV absorption spectra of EP, (h) NEP, (i) DA (inset: color under natural light); (j) UV absorption linear plots of EP, (l) NEP, (l) DA;

[0037] Figure 14 This is a diagram of the Fe3O4 QDs fluorescence sensor disclosed in the examples of this application visually detecting catecholamines in human serum;

[0038] Figure 15 This is a comparison chart of the dual-mode measurement of catecholamine content in human serum samples using fluorescence sensing and UV absorption of Fe3O4 QDs disclosed in the examples of this application. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0040] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0042] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0043]

Detection method

[0044] This detection method detects the fluorescence value of ferroferric oxide quantum dots at an excitation wavelength of 280 to 350 nm and / or the ultraviolet absorption value at a wavelength of 220 to 350 nm under the conditions of adding a buffer and a target analyte.

[0045] It can be understood that by collecting the fluorescence and UV absorption values ​​of the ferroferric oxide quantum dots, it is possible to determine whether the target analyte contains catecholamines or the specific amount of catecholamines. The operating principle of determining the specific amount of catecholamines based on the fluorescence and UV absorption values ​​is generally known in the field of fluorescent probes or sensors and can be found in Chinese Patent Document CN109211849A.

[0046] Here, taking fluorescence value as an example, we first introduce the principle of detecting catecholamines by obtaining fluorescence value. Specifically, catecholamines are rapidly oxidized, recombined, and reoxidized into P-EP, P-NEP, and P-DA in the buffer. Due to the internal filtration effect of these oxidation products on the ferroferric oxide quantum dots, the fluorescence of the ferroferric oxide quantum dots is linearly quenched, that is, the fluorescence intensity decreases with the increase of the concentration of catecholamines in the target object to be detected, that is, the fluorescence intensity shows a linear quenching relationship. Based on this principle, the actual operation of the detection is:

[0047] S1. Obtain a standard curve, i.e., a standard solution of catecholamines of known concentrations, and detect a series of catecholamine concentrations and fluorescence intensities to form a linear relationship between the standard curve. The standard curve reflects the preset correspondence between catecholamine concentrations and fluorescence intensities.

[0048] S2. Collect the fluorescence values ​​of the target analyte in two conditions: without adding a buffer and the target analyte, and with adding a buffer and the target analyte.

[0049] S3. Based on the measured fluorescence value and combined with the standard curve, the concentration of catecholamines in the target analyte can be obtained.

[0050]

Synthesis of Fe3O4 Quantum Dots

[0051] The synthesis of the ferroferric oxide quantum dots of the present application can be carried out by any known method. As an example, the preparation method of the ferroferric oxide quantum dots is as follows:

[0052] Fe3O4 NPs and ascorbic acid are put into an autoclave for hydrothermal reaction, and after cooling and separation, a mother liquor of ferroferric oxide quantum dots is obtained, which is placed in a low temperature environment for use.

[0053] For further demonstration, the following methods can be used:

[0054] 2.0 mg of Fe3O4 NPs and 220 mg of ascorbic acid (AA) were mixed in 20 mL of distilled water. The mixture was stirred vigorously for 30 min and placed in a 40 mL polytetrafluoroethylene-lined autoclave. It was heated at 200 °C for 2 h and then cooled to room temperature. The mixture was filtered through a 0.22 μm aqueous filter to retain the brownish-yellow liquid to obtain 100 μg mL -1 The mother solution was placed in a refrigerator at 4°C until use.

[0055]

Related structure / performance parameters of Fe3O4 quantum dots

[0056] like Figure 1 , is the transmission electron microscope (TEM) spectrum of Fe3O4 QDs. Figure 1 It can be seen that the Fe3O4 QDs are evenly dispersed. Figure 1 As can be observed in the inset, the particle size of Fe3O4 QDs is approximately 3.5 nm, and the lattice fringe spacing is 0.2789 nm and 0.2786 nm.

[0057] Fe3O4 NPs and Fe3O4 QDs were characterized by XRD. Figure 2 As shown, the 2θ values ​​of Fe3O4 NPs and Fe3O4 QDs are 29.85°, 35.39°, 43.29°, 49.19°, 56.98°, and 62.88°, corresponding to the (220), (331), (400), (420), (511), and (440) crystal planes, respectively. The positions and intensities of these peaks correspond to the XRD standard card for Fe3O4, numbered JCPDS No. 75-0449. Compared with Fe3O4 NPs, Fe3O4 QDs exhibit a distinct new peak at the (420) crystal plane, and the crystal plane structures of the two do not change significantly. This indicates that the Fe3O4 QDs were successfully synthesized.

[0058] The surface chemical compositions of Fe3O4 NPs and Fe3O4 QDs were characterized by XPS. Figure 3As shown in Table 1, both Fe3O4 NPs and Fe3O4 QDs have three strong peaks at 282.47, 533.81, and 712.56 eV, which are the signal peaks of C1s, O1s, and Fe2p, respectively. The content composition of Fe3O4 NPs (C1s: 23.28%, O1s: 51.19%, Fe2p: 25.53%) and Fe3O4 QDs (C1s: 63.48%, O1s: 34.9%, Fe2p: 1.62%) is shown in Table 1. The largest difference between the two is the content of Fe2p.

[0059] Table 1 Ratios of elements in the full spectrum

[0060]

[0061] Figure 4 shows the XPS peak analysis of Fe3O4 NPs and Fe3O4 QDs. Figures 4(a, b, c) show the high-resolution XPS spectra of C1s, O1s, and Fe2p of Fe3O4 NPs, respectively. Figure 4(a) primarily contains two peaks: CC / C=C (284.8 eV) and CO (286.8 eV). Figure 4(b) primarily contains two peaks: OH (529.5 eV) and CO (530.6 eV). Figure 4(c) primarily contains two peaks, which can be attributed to Fe2p1 / 2 and Fe2p3 / 2. Figures 4(d, e, f) show the high-resolution XPS spectra of C1s, O1s, and Fe2p of Fe3O4 QDs, respectively. Figure 4(d) primarily contains three peaks: CC / C=C (284.8 eV), CO (286.3 eV), and COC (288.6 eV). Figure 4(e) primarily contains two peaks, attributed to OH (531.8 eV) and CO (533.1 eV). Figure 4(f) primarily contains two peaks, attributed to Fe2p1 / 2 and Fe2p3 / 2. Comparison of the Fe2p spectra of Fe3O4 NPs and Fe3O4 QDs further confirms the successful synthesis of Fe3O4 QDs.

[0062] Fe3O4 QDs have excellent water solubility and good fluorescence properties. Figure 5 It can be seen that Fe3O4 QDs have a broad absorption spectrum. When the excitation wavelength is 330 nm, the maximum emission wavelength of Fe3O4 QDs is located at 417 nm. Figure 5 As can be seen from the inset, the solution appears brownish-yellow under visible light and emits blue fluorescence under 365nm ultraviolet light.

[0063] The quantum yield of Fe3O4 QDs was calculated using quinine sulfate solution as a reference standard (R = 0.95).

[26] The quantum yield (QY) of the synthesized Fe3O4 QDs was calculated to be 69.1%. The QY was calculated using the following formula:

[0064]

[0065] In the above formula, Ψ and Ψ R represent the fluorescence quantum yield of Fe3O4 QDs and the fluorescence quantum yield of the reference solution quinine sulfate, respectively, and Ψ R =0.54, I and I R A and A represent the fluorescence quantum yield of Fe3O4 QDs and the integrated fluorescence intensity of quinine sulfate reference solution, respectively. R represent the fluorescence quantum yield of Fe3O4 QDs and the absorbance of the reference solution quinine sulfate, η R and η represent the fluorescence quantum yield of Fe3O4 QDs and the refractive index of the reference solution quinine sulfate, respectively, both of which are 1.33 here.

[0066]

pH of addition conditions

[0067] As a preferred implementation of the present application, the pH value of the addition condition corresponding to the target analyte may be 8-14.

[0068] The specific design considerations for the pH values ​​above are: Appropriate pH is very important for fluorescent probes because it has protonation and deprotonation effects. Therefore, taking epinephrine (EP) as an example, the effect of 200 μM epinephrine on 2.0 μg mL -1 The effect of Fe3O4 QDs fluorescence quenching, the results are as follows Figure 6 As the pH increases from 2 to 12, the degree of fluorescence quenching gradually increases. When the pH is 13.0, the quenching degree reaches the maximum, and then decreases at pH 14.0. The reason why the quenching degree reaches the maximum at pH 13.0 is speculated as follows: This is mainly because as the alkalinity of the system increases, catecholamines are increasingly easily oxidized into quinones, and then reorganized, reoxidized, and finally polymerized into polyepinephrine (P-EP), polynorepinephrine (P-NEP) and polydopamine (P-DA). The conversion process is speculated as follows Figure 7 shown.

[0069] Based on the aforementioned speculation that catecholamines are converted to quinones, to further explore the reason why the quenching degree reaches its maximum at pH 13.0, the UV-Vis absorption spectra of epinephrine and polyepinephrine (P-EP) as well as the excitation and emission spectra of Fe3O4 QDs were measured under optimal conditions, using EP as a representative. The results are shown in Figure 8(a). Under the same concentration conditions, the absorption range and absorption intensity of P-EP (λmax = 285, 355 nm) are much greater than those of EP (λmax = 285 nm), and both overlap with the excitation (λex = 330 nm) and emission peaks (λem = 417 nm) of Fe3O4 QDs. Therefore, P-EP is more likely to form an inner filter effect (IFE) or fluorescence resonance energy transfer (FRET) with Fe3O4 QDs than EP, resulting in a better quenching effect. In addition, from the ultraviolet absorption spectra of the four systems of Fe3O4 QDs, EP, P-EP and Fe3O4 QDs+P-EP (8(b)), it can be seen that neither EP nor P-EP produces new peaks after reacting with Fe3O4QDs, that is, no new substances are produced, which further indicates that the inner filter effect between P-EP and Fe3O4 QDs plays a dominant role.

[0070] Fluorescence lifetime is considered to be one of the effective methods to distinguish IFE and FRET. Taking EP as an example, under the optimal conditions, the fluorescence lifetime of Fe3O4 QDs before and after adding EP was tested. The results are shown in Figure 2. Figure 14 As shown in (c): The fluorescence lifetimes of Fe3O4 QDs before and after the addition of EP are τ0 = 7.747ns and τ = 7.678ns, respectively, and τ0 / τ = 1.008. It is speculated that the fluorescence quenching mechanism of P-EP on Fe3O4 QDs is mainly due to IFE rather than FRET.

[0071] Buffer

[0072] Preferable types include sodium hydroxide and BR buffer solution.

[0073]

Dosage concentration

[0074] The more suitable concentration of ferroferric oxide quantum dots in this application is 1-2 μg mL -1 The dosage concentration is defined as the ratio of the mass of the ferroferric oxide quantum dots to the volume of the liquid consisting of the buffer and the target analyte.

[0075] The specific design considerations for the above Fe3O4 QDs concentration are: To obtain the best sensitivity, we optimized the dosage of Fe3O4 QDs. Taking EP as an example. First, the concentration of EP was fixed at 100μM, and 625μL of pH 13.0 NaOH buffer solution was added to investigate the effect of the Fe3O4 QDs dosage on the fluorescence intensity. The results are shown in Figure 2. Figure 10 As shown, when the quantum dot concentration is 1.5 μg mL -1 When the fluorescence quenching degree is the largest, it is particularly preferred that the optimal concentration of Fe3O4 QDs is 1.5 μg mL -1 .

[0076] Contact time

[0077] The more suitable contact time for this application is 0.5 to 30 minutes.

[0078] The specific design considerations for the above contact time are: considering the analysis speed, the reaction time between Fe3O4 QDs solution and catecholamines was explored, with EP as the representative, and the concentration of Fe3O4 QDs was fixed at 1.5 μg mL -1 The concentration of EP was fixed at 100 μM, and 625 μL of pH 13.0 NaOH buffer solution was added and the volume was fixed with distilled water. The reaction time was tested and the fluorescence spectrum was recorded within the time range of 0-30 min. The results are shown in Figure 2. Figure 11 As shown in the figure, in the presence of EP, the fluorescence intensity of Fe3O4 QDs remains almost constant from 0.5 to 30 minutes, indicating that the probe responds quickly to epinephrine, that is, the probe responds quickly to catecholamines. Therefore, after comprehensive consideration, 1 minute was selected as the optimal reaction time.

[0079] [Example of detection method]

[0080] A. Preparation of actual samples

[0081] Serum samples were obtained from the Laboratory Department of Huangshi No. 2 Hospital (provided voluntarily by patients). The samples were centrifuged at 3500 rpm for 20 minutes, and the supernatant was collected for later use.

[0082] B. Detection of catecholamines in actual samples

[0083] Add a certain volume of serum sample to each test tube, and then add 75 μL of 1.0 μg mL - 1The Fe3O4 QDs solution was mixed, and then 625 μL of pH 13.0 NaOH solution was added as a buffer solution. After mixing, the volume was adjusted to 5.0 mL with distilled water. Ultrasonic treatment was performed at room temperature for 30 seconds. The fluorescence value of the sample at an emission wavelength of 417 nm under an excitation wavelength of 330 nm and its ultraviolet absorption value at a wavelength of 285 nm were tested respectively.

[0084] Evaluation of detection methods

[0085] Evaluation process

[0086] The actual sample data were statistically analyzed using the following method. Specifically, the measurement data of the actual samples were analyzed using Origin 8.5 and SPSS Statistics 27 software. The measurement data were in accordance with the normal distribution. The standard curve regression equation was fitted using Origin 8.5. Pearson analysis was used to test the correlation between the absorption spectrum of Fe3O4QDs and the fluorescence sensing dual mode. The test level was α = 0.05 (both sides).

[0087] Evaluation results

[0088] A. Evaluation of quantitative in vitro catecholamine detection

[0089] Under optimal conditions, the analytical performance of Fe3O4 QDs for the detection of various concentrations of EP, NEP, and DA was investigated using dual-mode detection using fluorescence sensing and UV absorption. A series of linearity, precision, and limit of detection (LOD) experiments were conducted, and the results are summarized in Figure 13 and Table 2. As can be seen, Fe3O4 QDs exhibited good linearity for the detection of EP, NEP, and DA using both fluorescence and UV absorption detection modes, with acceptable regression coefficients (R 2 ) (0.9902-0.9975), good linear ranges (0.5-320, 1.0-320, and 1-380 μM), and low limits of detection (0.14-0.33 μM). This indicates that the proposed method is relatively stable and can be used for dual-mode detection of EP, NEP, and DA using both absorption spectroscopy and fluorescence sensing.

[0090] Table 2 Related performance of Fe3O4 QDs in detecting catecholamines

[0091]

[0092] Table note: F: Fluorometric sensing; C: Colorimetric sensing

[0093] Table 3 summarizes the performance comparison of the fluorescence and colorimetric dual-mode method with other fluorescence sensors for detecting EP, NEP, and DA. The LOD of this method is higher than that of An et al., similar to that of Dipika et al. and Le et al., but lower than that of Samira et al. However, this method significantly offers the highest quantum yield and the shortest response time, offering the advantage of rapid detection.

[0094] Table 3 Performance comparison of this method with other catecholamine sensing platforms

[0095]

[0096] B. Evaluation of Qualitative Detection of Catecholamines in Vitro

[0097] As shown in Figure 13, after adding NaOH with pH 13.0 to the EP, NEP and DA solutions, they were oxidized to quinones, and then Fe3O4 QDs were added. The color changes of EP, NEP and DA with different concentrations (0, 5, 20, 50, 100, 150, 200, 250, 300 μM) were observed under 365 nm UV light. The results are shown in Figure 13(a): As the concentration of catecholamines increases, the color of EP gradually changes from blue to yellow fluorescence, the color of NEP gradually changes from blue to green fluorescence, and the color of DA gradually changes from blue to a deeper blue fluorescence. Figures 13(b), (c) and (d) show the color changes of standard solutions and serum sample solutions of EP, NEP and DA of different concentrations sensed by Fe3O4 QDs, respectively. By comparing the colors of standard solutions, serum samples and their spiked solutions, it is basically possible to achieve visual and semi-quantitative detection of EP, NEP and DA in serum samples without any sample pretreatment. It is convenient, rapid, easy to detect on-site, simple, intuitive and has a wide detection range. It has great application value in the determination of EP, NEP and DA in serum samples.

[0098] C. Detection of catecholamines in human serum

[0099] Under optimal conditions, a dual-mode detection method based on Fe3O4 QDs fluorescence sensing and UV absorption was used to analyze catecholamines in human serum samples. The feasibility of the method was verified, and spike recovery experiments were conducted. Table 4 shows the determination and recovery of catecholamines in the serum of hypertensive patients. The results showed that the dual-mode detection of EP, NEP, and DA in the serum of the same hypertensive patient was successful. The results of the two methods were consistent, with spike recoveries ranging from 91.2% to 104.9% and RSDs less than 5%. This demonstrates that the dual-mode detection method based on Fe3O4 QDs fluorescence sensing and UV absorption has excellent potential for the detection of catecholamines in human serum.

[0100] In order to further verify the correlation between the fluorescence sensing and UV absorption dual-mode detection method, the actual samples were analyzed using Origin and SPSS software. The results are shown in Figure 2. Figure 14 As shown in Tables 5, 6, 7, and 8, the results show a strong correlation between fluorescence sensing and UV absorption. The Passing-Bablok regression equation is Y = 0.99904X - 0.1679, and the correlation coefficient (r) is 0.99993. P < 0.01 indicates a significant correlation between the two methods.

[0101] Table 4 Determination of catecholamines in actual samples

[0102]

[0103] Table note: F: Fluorometric sensing; C: Colorimetric sensing

[0104] Table 5 Determination of EP in actual samples

[0105]

[0106] Table note: F: Fluorometric sensing; C: Colorimetric sensing

[0107] Table 6 Determination of NEP in actual samples

[0108]

[0109]

[0110] Table note: F: Fluorometric sensing; C: Colorimetric sensing

[0111] Table 7 Determination of DA in actual samples

[0112]

[0113] Table note: F: Fluorometric sensing; C: Colorimetric sensing

[0114] Table 8 Correlation analysis of fluorescence sensing and UV absorption dual mode method using SPSS

[0115]

[0116] Table note: F: fluorometric sensing, C: colorimetric sensing

[0117] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A method for detecting catecholamines, characterized in that: Under the conditions of adding buffer and target analyte, the fluorescence value of ferroferric oxide quantum dots at an excitation wavelength of 280-350nm and the ultraviolet absorption value at a wavelength of 220-350nm were detected; The pH value of the addition condition corresponding to the target analyte is 13; The buffer is a sodium hydroxide buffer solution; The dosage concentration of the ferroferric oxide quantum dots is 1.5 μg mL -1 The dosage concentration is defined as the ratio of the mass of the ferroferric oxide quantum dots to the volume of the liquid consisting of the buffer and the target analyte; The contact time between the ferroferric oxide quantum dots and the target object to be detected is 1 minute.

2. The detection method according to claim 1, characterized in that The XRD spectrum parameters of the ferroferric oxide quantum dots are: 。 3. The detection method according to claim 1, characterized in that The XPS spectrum parameters of the ferroferric oxide quantum dots are: 。 4. The method for detecting catecholamines according to claim 1, wherein The preparation method of the ferroferric oxide quantum dots is as follows: Fe3O4NPs and ascorbic acid were mixed in distilled water to prepare a mixture solution; The mixture solution was stirred and placed in an autoclave for heating. After cooling to room temperature, it was filtered to retain the brown-yellow liquid to obtain the mother liquor of ferroferric oxide quantum dots, which was placed in a low-temperature environment for later use.

5. A detection probe for detecting catecholamines using the detection method according to claim 1, characterized in that: Contains Fe3O4 quantum dots.

6. A detection sensor for detecting catecholamines using the detection method according to claim 1, characterized in that: Contains Fe3O4 quantum dots.

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