A method for rapid detection of CTCs

Abstract

This invention discloses a rapid method for detecting CTCs, belonging to the field of tetracycline detection technology. The invention uses a fluorescence spectrometer to measure the fluorescence intensity of the test solution containing fluorescent probes PEI-CuNCs and a surfactant. Compared with the fluorescence intensity of PEI-CuNCs, if a new blue fluorescence emission band appears at 425 nm and the blue-green fluorescence at 500 nm decreases, then the test solution contains CTCs. The detection method of this invention has advantages such as simple operation, speed, high sensitivity, good selectivity, low detection limit, and low cost. It does not require large-scale instruments or professional operators, and shows good spiked recovery rate in actual water sample testing, with reliable detection results and excellent practicality.

Description

Technical Field

[0001] This invention belongs to the field of tetracycline detection technology, and more specifically, relates to a method for rapid detection of chlortetracycline (CTC). Background Technology

[0002] Chlortetracycline (CTC), the first tetracycline antibiotic (TC) discovered, is also known as "chlorotetracycline." It inhibits most Gram-positive bacteria, Gram-negative bacteria, and rickettsiae. The main difference between CTC and other TCs lies in the Cl at the 7-position, which makes it more permeable to biofilms, has a broader range of action, is more toxic, and is more easily absorbed by cells. CTC exhibits cross-resistance with other TC antibiotics. Due to the widespread use of TCs, common clinical pathogens also show strong resistance to CTC. Currently, TCs in the environment mainly originate from livestock farming, hospital and pharmaceutical factory wastewater. While CTCs do bring some benefits to human and animal health, their uncontrolled use has caused significant harm. Due to accumulation in the food chain, CTCs eventually remain in the human body, posing a threat to human health. TCs can be deposited in bone and tooth tissues, combining with calcium deposited in newly formed bone and teeth, resulting in yellow deposits on teeth. In addition, they can accumulate in liver, stomach and intestinal tissues, causing tissue damage, and can also cause allergic reactions and teratogenic effects. Therefore, it is very important to establish a method for detecting CTCs.

[0003] Currently, various methods for quantitative analysis and detection of CTCs have been established, including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), ultraviolet-visible spectroscopy (UV-Vis), mass spectrometry (MS), and immunoassay. However, most of these methods involve expensive equipment and require highly skilled operators, or they are simple to operate and inexpensive but lack sufficient sensitivity. Therefore, it is essential to develop more sensitive, selective, and cost-effective CTC detection methods. CTCs themselves possess optical properties such as ultraviolet / visible absorption, fluorescence, and quantum yield. The position and intensity of the fluorescence spectrum of the same CTC may differ significantly in different solvents. If the solvent and the fluorescent substance form a complex, or if the solvent alters the ionization state of the fluorescent substance, the fluorescence spectrum will also change. When a surfactant is added to the solution of the fluorescent substance, based on the solubilization principle, deprotonation, and other effects of the surfactant, the fluorescence spectrum of the fluorescent substance will be enhanced, thus increasing its sensitivity.

[0004] Surfactants have a wide range of applications in various fields, but there is not much research on their use in material analysis and detection, especially in the analysis and detection of CTC. Summary of the Invention

[0005] In view of the above-mentioned problems in the existing technology, the technical problem to be solved by the present invention is to provide a simple, fast, highly sensitive and specific method for detecting CTC.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A rapid method for detecting CTC involves using a fluorescence spectrometer to measure the fluorescence intensity of a test solution containing fluorescent probes PEI-CuNCs and a surfactant. If, compared to the fluorescence intensity of PEI-CuNCs, the blue-green fluorescence at 500 nm decreases and a new blue fluorescence emission band appears at 425 nm, then the test solution contains CTC.

[0008] The method for rapid detection of CTC involves adding PEI-CuNCs at a volume percentage of 1% to the system to be tested.

[0009] The method for rapid detection of CTC uses CTAB as the surfactant added to the test system.

[0010] The rapid detection method for CTCs uses a CTAB mass percentage concentration of 0.1%.

[0011] The method for rapid detection of CTCs controls the pH of the test system to be 6.

[0012] A method for rapid detection of CTCs, the steps are as follows:

[0013] 1) Preparation of fluorescent probes PEI-CuNCs;

[0014] 2) Plotting the CTC standard concentration gradient curve;

[0015] CTC solutions of different concentrations were prepared, and CTAB and PEI-CuNCs were added respectively. After the reaction was carried out at room temperature in the dark, the fluorescence intensity of the system was measured using a fluorescence spectrometer. The fluorescence intensity ratio F was then used to determine the fluorescence intensity of the system. 425 / F 500 The difference ΔF 425 / F 500 Plot the linear relationship curve; the linear regression equation for CTC is y = 0.4292x + 0.1482;

[0016] 3) Testing of the system to be tested;

[0017] The ΔF of the test system was determined using the same detection method as in step 2). 425 / F 500 The concentration of CTC in the test system is calculated using the curve from step 2).

[0018] The method for rapid detection of CTC has a linear concentration range of 0-10 μmol / L and a detection limit of 0.96 nmol / L.

[0019] In the rapid detection method for CTC, step 1) involves the preparation of the fluorescent probe PEI-CuNCs as follows: Cu(NO3)2 solution is added to PEI solution, and the mixture is stirred thoroughly for 10 minutes at room temperature. Then, ascorbic acid solution is added, and the reaction is carried out in the dark with controlled temperature. After the solution is cooled to room temperature, it is filtered through a 0.45μm microporous filter to obtain a dark brown PEI-CuNCs solution.

[0020] In the rapid detection method for CTC, in step 1), the volume of the Cu(NO3)2 solution is 4.5 mL and the concentration is 0.1 mol / L, and the volume of the PEI solution is 90 mL and the concentration is 30 mg / mL.

[0021] The method for rapid detection of CTCs involves a temperature control of 80°C and a reaction time of 200 rpm in the dark for 8 hours.

[0022] In the rapid detection method for CTC, step 2) involves preparing CTC solutions of different concentrations and adding them to a 20 mmol / L, pH 6 acetic acid buffer solution containing 0.1% CTAB by mass and 1% PEI-CuNCs by volume. After reacting at room temperature in the dark, the fluorescence intensity of the system is measured using a fluorescence spectrometer.

[0023] The method for rapid detection of CTCs controls the pH of the test system to be 6.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1) The ratiometric sensor constructed in this invention utilizes the amplification effect of PEI-CuNCs and surfactants on the fluorescence signal of CTC, the binding ability of PEI and CTC, and the fluorescence response of CTC to PEI-CuNCs to achieve rapid, simple, and sensitive detection of the target analyte CTC, solving the problems of poor stability, difficulty in on-site detection, and difficulty in visualization of existing detection methods.

[0026] 2) The PEI-CuNCs used in this invention have unique optical properties, low toxicity and good biocompatibility, and are simple to prepare and low in cost.

[0027] 3) The fluorescence sensitization method constructed in this invention has good specificity and strong anti-interference ability. It can not only distinguish CTC from other common interfering substances, but also distinguish CTC from tetracycline antibiotics with similar structures.

[0028] 4) The present invention has a good spike recovery rate in the detection of actual water samples, and the detection results are reliable. Attached Figure Description

[0029] Figure 1 The image shows the prepared PEI-CuNCs solution. In the image, A is a photograph of PEI-CuNCs under fluorescent light, and B is a fluorescence photograph under a 365nm ultraviolet light.

[0030] Figure 2 The fluorescence excitation and emission spectra and UV-Vis absorption spectra of the prepared PEI-CuNCs are shown.

[0031] Figure 3 TEM image of the prepared PEI-CuNCs;

[0032] Figure 4 The particle size distribution of the prepared PEI-CuNCs is shown in the diagram.

[0033] Figure 5 This is a schematic diagram illustrating the working principle of a ratiometric fluorescence sensor for detecting chlortetracycline.

[0034] Figure 6 This is a feasibility analysis diagram; the buffer solution is acetate buffer (20 mmol / L, pH=6), the CTC concentration is 10 μmol / L, the mass percentage of CTAB in the buffer solution is 0.1%, and the PEI-CuNCs account for 1% (v / v) of the system.

[0035] Figure 7 Line graph showing the effect of different PEI-CuNCs concentrations on the fluorescence of the system; the buffer was acetate buffer (20 mmol / L, pH=6, containing 0.1% CTAB), and the concentration of CTC was 10 μmol / L;

[0036] Figure 8 The spectrum shows the effect of different surfactants on the fluorescence intensity of CTC; the buffer solution was acetate buffer (20 mmol / L, pH=6), the concentration of CTC was 10 μmol / L, and the concentration of surfactant was 0.1%.

[0037] Figure 9 Line graph showing the effect of different concentrations of CTAB on the fluorescence of the system; where the buffer is acetate buffer (20 mmol / L, pH=6), PEI-CuNCs account for 1% (v / v) of the system, and the concentration of CTC is 10 μmol / L;

[0038] Figure 10The spectrum shows the effect of CTC on the fluorescence intensity of PEI-CuNCs at different pH values; where pH 4-6 is 20 mmol / L acetate buffer (containing 0.1% CTAB), pH 7-10 is 20 mmol / L BR buffer (containing 0.1% CTAB), PEI-CuNCs account for 1% (v / v) of the system, and the concentration of CTC is 10 μmol / L;

[0039] Figure 11 The ratio of CTC concentration to the difference in fluorescence intensity of the system (F) 425 / F 500 Linear relationship diagram;

[0040] Figure 12 This is a specificity graph for common antibiotics; in the graph, the concentration of CTC is 1 μmol / L, while the concentrations of the other 4 TCs (tetracycline TC, oxytetracycline OTC, doxycycline DC, methacycline MTC), 3 fluoroquinolone antibiotics (FQs: ciprofloxacin CIP, enrofloxacin ENR, norfloxacin NOR), 2 macrolide antibiotics (MA: roxithromycin ROX, erythromycin ERY), and 1 sulfonamide antibiotic (SAs: sulfathiazole STZ) are all 2 μmol / L.

[0041] Figure 13 This is a specificity diagram of common interfering substances in water; in the diagram, the CTC concentration is 1 μmol / L, and the eight common water ions (Ca) are also present. 2+ Mg 2+ Na + K + CO3 2- HCO3 - SO4 2- Cl - The concentrations of interfering substances, including 2 types of humic acid (FA and HA) and 4 types of amino acids (Hisidine, Glycine, Lysine, and Glutamic Acid), were all 500 μmol / L. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to specific embodiments. Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art. The experiments mainly utilized equipment such as the LS-55 fluorescence spectrophotometer (PerkinElmer, USA) and the UV-2700 ultraviolet-visible spectrophotometer (Shimadzu, Japan).

[0043] Example 1

[0044] 1. Preparation of PEI-CuNCs

[0045] 1) PEI-CuNCs with good optical properties were prepared by a one-pot method.

[0046] Add 90 mL of 30 mg / mL PEI solution and 4.5 mL of 0.1 mol / L Cu(NO3)2 solution to a round-bottom flask, so that PEI(MW600) and Cu... 2+ The molar ratio of the two components was 10:1. The mixture was stirred at room temperature for 10 min, and then 5.4 mL of 1 mol / L ascorbic acid (AA) solution was added. The mixture was stirred at room temperature for 5 min. After preparation, the mixture was placed in a rotary evaporator and reacted at 80 °C and 200 rpm in the dark for 8 h. After the solution was cooled to room temperature, it was filtered through a 0.45 μm microporous filter to obtain a dark brown PEI-CuNCs solution, which was then stored in a sealed container at 4 °C.

[0047] 2) Characterization of the prepared PEI-CuNCs

[0048] Figure 1 The image shows the color of the prepared PEI-CuNCs solution. In the image, A is a photograph of PEI-CuNCs under fluorescent light, and B is a fluorescence photograph under 365nm ultraviolet light. Under fluorescent light, it appears as a deep yellow-brown color, and under ultraviolet light, it exhibits a very bright blue-green fluorescence, indicating that PEI-CuNCs were successfully prepared.

[0049] Figure 2 These are the fluorescence (Ex.) excitation and emission (Em.) spectra and the UV-Vis absorption (Abs.) spectra of the prepared PEI-CuNCs. For example... Figure 2 As shown, the prepared PEI-CuNCs have a main fluorescence excitation peak at 345 nm and a side fluorescence excitation peak at 425 nm, and a fluorescence emission peak at 500 nm. The optimal excitation and emission wavelengths are 345 nm and 500 nm, respectively. In the UV-Vis absorption spectrum, the absorption side peak of the prepared PEI-CuNCs is located at 340 nm, indicating that PEI-CuNCs emitting blue-green fluorescence were successfully prepared.

[0050] Figure 3 The image shows a TEM image of the prepared PEI-CuNCs. The synthesized PEI-CuNCs are approximately spherical with most of them having a size of less than 5 nm. They are uniform in size and evenly distributed, making them suitable for subsequent analysis and detection of substances.

[0051] Figure 4 The particle size distribution of the prepared PEI-CuNCs is shown in the figure. The PEI-CuNCs have a small particle size with an average particle size of about 3.2 nm, which is suitable for subsequent analysis and detection of substances.

[0052] 3) PEI-CuNCs are used to detect chlortetracycline (CTC).

[0053] PEI-CuNCs (1%, v / v) and the test system containing CTC were added sequentially to an acetate buffer containing 0.1% CTAB. The acetate buffer concentration was 20 mmol / L and pH = 6. After thorough mixing, the mixture was allowed to stand in the dark for 20 min. The color change was observed by irradiation with a 365 nm UV lamp, and the fluorescence spectrum was measured using a fluorescence analyzer.

[0054] like Figure 5 As shown, the working principle of the ratiometric fluorescent probe PEI-CuNCs for detecting CTC is as follows: Under weakly acidic conditions (pH 6), PEI-CuNCs exhibit blue-green fluorescence emission at 500 nm upon excitation at 345 nm. Adding CTC and the surfactant cetyltrimethylammonium bromide (CTAB) to the PEI-CuNCs test system reduces the fluorescence at 500 nm, while a new fluorescence emission band appears at 425 nm. Under weakly acidic conditions (pH 6), a large number of amino groups in the PEI structure undergo protonation, causing the zwitterionic CTC cations in the solution to deprotonate and bind together. The micelles formed by CTAB in the solution can encapsulate the bound PEI-CuNCs / CTC, preventing intermolecular collisions and reducing the probability of collisional quenching of fluorescence, thus significantly amplifying the fluorescence signal at 425 nm. Simultaneously, the fluorescence of PEI-CuNCs is quenched by CTC due to the internal filtering effect (IFE) between PEI-CuNCs and CTC molecules, resulting in a decrease in fluorescence at 500 nm. Based on the quenching effect of CTC on the fluorescence of PEI-CuNCs and the amplification effect of PEI-CuNCs and the surfactant CTAB on the fluorescence signal of this system, a ratiometric fluorescent probe-based rapid detection method for CTC was constructed.

[0055] Figure 6This is a feasibility analysis diagram of the present invention. First, the fluorescence intensity of CTC and PEI-CuNCs (1%, v / v) in acetate buffer (20 mmol / L) at pH 6 was investigated. Then, the effects of adding CTAB (0.1%) and PEI-CuNCs (1%, v / v) separately on the fluorescence intensity of CTC were investigated. Finally, the effects of adding CTAB and PEI-CuNCs to the buffer solution simultaneously on the fluorescence intensity of CTC were investigated. In acidic media, CTC is a non-luminescent material, while PEI-CuNCs emit blue-green fluorescence at 500 nm when excited at 345 nm. When CTAB is added to PEI-CuNCs, the fluorescence intensity remains almost unchanged, indicating that CTAB does not affect the fluorescence of PEI-CuNCs. However, CTAB can enhance the fluorescence intensity of CTC, causing the system to emit blue fluorescence at 425 nm. When CTC is added to PEI-CuNCs, the fluorescence value of PEI-CuNCs at 500 nm decreases, while the fluorescence intensity of CTC at 425 nm increases slightly. When PEI-CuNCs and CTAB coexist in the system, the fluorescence at 425 nm is significantly enhanced, mainly because CTC is completely protonated in the acidic medium under the synergistic effect of CTAB and PEI-CuNCs, which improves its fluorescence. At the same time, the fluorescence at 500 nm in the system is also slightly enhanced, mainly because the fluorescence at 425 nm is too strong, resulting in a fluorescence superposition effect. This indicates that PEI-CuNCs can be used as a fluorescent probe in this system, and CTAB, as a fluorescence sensitizer, can help improve the sensitivity of this system in detecting CTC.

[0056] 2. Determination of PEI-CuNCs concentration in the detection system

[0057] PEI-CuNCs concentrations of 0.5%, 1%, 3%, 5%, 8%, and 10% were set in acetate buffer (20 mmol / L, pH=6) containing 0.1% CTAB. Control and experimental groups (0 and 10 μmol / L CTC) were also set up. The fluorescence intensity of the systems was detected. Figure 7 As shown, when PEI-CuNCs account for 1% of the system, ΔF 425 / F 500 When the value reaches its maximum, and the concentration of PEI-CuNs is greater than 1%, it will compete with CTAB and inhibit the fluorescence enhancement effect of CTAB on this system. Therefore, 1% PEI-CuNCs was selected to establish a fluorescence analysis method for detecting CTC.

[0058] 3. Determination of surfactants and their concentrations in the detection system.

[0059] CTC was added to acetate buffer (20 mmol / L, pH = 6) containing 0.1% Tween 20, Triton X-100, PDDA, and CTAB, respectively, to set the final CTC concentration to 10 μmol / L. Figure 8 As shown, compared to other surfactants, the cationic surfactant CTAB exhibits the most significant fluorescence enhancement effect on CTC. This is because, in a weakly acidic environment at pH 6, the micelle environment formed by CTAB is relatively stable and ordered. PEI-CuNCs / CTC are dispersed into the micelle core or palisade region, reducing their degrees of freedom. The micelle-encapsulated PEI-CuNCs / CTC effectively avoids intermolecular collisions, reducing the probability of collisional extinguishing of fluorescence, thereby significantly amplifying the fluorescence ratio signal F of this system. 425 / F 500 Value; while PDDA and nonionic surfactants, compared with the surfactant-free control group, F 425 / F 500 The values ​​hardly changed, so CTAB was chosen to establish a fluorescence assay for the detection of CTCs.

[0060] To further optimize the concentration of CTAB, CTAB concentrations of 0%, 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, and 0.5% were prepared in acetate buffer (20 mmol / L, pH = 6). Control and experimental groups (0 and 10 μmol / L CTAB) were also established, and the fluorescence intensity of the systems was measured. Figure 9 As shown, PEI-CuNCs account for 1% (v / v) of the system. When CTAB accounts for more than 0.1% of the acetate buffer solution, the system's ΔF 425 / F 500 The value gradually reaches saturation, so a CTAB concentration of 0.1% is chosen.

[0061] 4. Determination of pH value of the detection system

[0062] CTC was diluted in buffer solutions of different pH values, and its fluorescence intensity was measured. Acetate buffer (pH = 3-6, 20 mmol / L) and BR buffer (pH = 7-10, 20 mmol / L) containing 0.1% CTAB were prepared, and 200 μmol / L CTC and 1% PEI-CuNCs were added to each, respectively. Fluorescence intensities of the control and experimental groups (0 and 10 μmol / L CTC) were measured. Figure 10 As shown, when the pH value is 6, the system ΔF 425 / F 500 Since the value is the largest, an acetate buffer solution with pH=6 is chosen.

[0063] Example 2

[0064] 1. Plotting the CTC standard concentration gradient curve

[0065] Different concentrations of CTC solutions were prepared, and PEI-CuNCs (1%, v / v) were added to 20 mmol / L acetate buffer solution (containing 0.1% CTAB) at pH 6, respectively, to achieve CTC concentrations of 0, 0.005, 0.01, 0.1, 0.2, 0.5, 1, 2, 4, 5, 6, 8, and 10 μmol / L. After reacting at room temperature for 20 min, the fluorescence intensity of the system was measured using a fluorescence spectrometer. With increasing CTC concentration, the fluorescence intensity at 425 nm gradually increased, while the fluorescence intensity at 500 nm initially decreased but then slightly increased due to the influence of the system's fluorescence. Figure 11 As shown, using the fluorescence intensity ratio F 425 / F 500 The difference (ΔF) 425 / F 500 Plot a linear relationship curve. Therefore, within the range of 0–10 μmol / L, ΔF 425 / F 500 The concentration of CTC showed a good linear relationship, with the linear regression equation being y = 0.4292x + 0.1482, R0. 2 =0.9898, the limit of detection (LOD, S / N=3) is 0.96 nmol / L, and the limit of quantitation (LOQ, S / N=10) is 58.5 nmol / L. The LOD is much lower than the EU and China's maximum residue limits (MRLs) of 100 μg / L (approximately 210 nmol / L) for CTC in animal-derived foods, including milk.

[0066] Example 3

[0067] 1. Specificity tests for common antibiotics

[0068] PEI-CuNCs (1%, v / v) were added to an acetate buffer (pH = 6, 20 mmol / L) containing 0.10% CTAB. Then, five TCs (CTC, TC, OTC, DC, MTC), three FQs (CIP, ENR, NOR), two MAs (ROX, ERY), and one SA (STZ) were added. The concentration of CTC was 1 μmol / L, and the concentrations of the other antibiotics were all 2 μmol / L. Additionally, eight common water ions (Ca) were also added. 2+ Mg 2+ Na + K + CO3 2- HCO3 - SO4 2- Cl- Two types of humic acids (FA and HA) and four types of amino acids (His, GIy, Lys, and GIu) were used, with CTC at a concentration of 1 μmol / L and other interfering substances at a concentration of 500 μmol / L. The fluorescence intensity was measured after a reaction time of 20 min. Figure 12 , 13 As shown, interfering substances have almost no effect on the system, and the constructed fluorescence platform has excellent selectivity only for CTC and strong anti-interference ability.

[0069] 2. Spiking experiment of CTC in actual water samples

[0070] To verify the practical application capability of the sensor in this experiment, spiked recovery experiments were conducted on pretreated Xuanwu Lake water, Hongze Lake water, Nongfu Spring mineral water, tap water from the Nanjing Forestry University laboratory, and milk from the school supermarket. The CTC concentrations were set at 0, 0.5 μmol / L, 1 μmol / L, and 2 μmol / L as the final spiked concentrations for each water sample. The fluorescence intensity of each water sample was measured using a fluorescence spectrometer. Three sets of experiments were repeated, and ΔF was selected. 425 / F 500 The recovery rate was analyzed using ultrapure water as a control group.

[0071] As shown in Table 1, the spiked recoveries of CTC in four actual water samples (mineral water, tap water, two types of lake water, and milk) using this method ranged from 91.1% to 103.3%, with relative standard deviations (RSD) ranging from 0.6% to 3.9%. This indicates that the system has high accuracy and reliability in detecting CTC in actual samples and is applicable to the qualitative and quantitative detection of CTC in various environments.

[0072] Table 1. Recovery rate analysis of actual water and milk samples.

[0073]

[0074]

[0075] The descriptions and practices disclosed in this invention are readily apparent and understandable to those skilled in the art, and various improvements and modifications can be made without departing from the principles of this invention. Therefore, modifications or improvements made without departing from the spirit of this invention should also be considered within the scope of protection of this invention.

Claims

1. A method for rapid detection of CTCs, characterized in that, The fluorescence intensity of the test solution containing the fluorescent probe PEI-CuNCs and surfactant was measured using a fluorescence spectrometer. If the blue-green fluorescence at 500 nm decreased and a new blue fluorescence emission band appeared at 425 nm compared with the fluorescence intensity of PEI-CuNCs, then the test solution contained CTC. The steps are as follows: 1) Preparation of fluorescent probe PEI-CuNCs; The preparation process of fluorescent probe PEI-CuNCs is as follows: Cu(NO3)2 solution is added to PEI solution, and stirred thoroughly at room temperature for 10 min. Then, ascorbic acid solution is added, and the reaction is carried out in the dark with controlled temperature. After the solution is cooled to room temperature, it is filtered with a 0.45 μm microporous filter to obtain a dark brown PEI-CuNCs solution. 2) Plotting the CTC standard concentration gradient curve; CTC solutions of different concentrations were prepared and added to a 20 mmol / L acetate buffer solution containing 0.1% CTAB by mass and 1% PEI-CuNCs by volume, at pH 6. After the reaction was carried out at room temperature in the dark, the fluorescence intensity of the system was measured using a fluorescence spectrometer. Using fluorescence intensity ratio F 425 / F 500 The difference ΔF 425 / F 500 Plot the linear relationship curve; the linear regression equation for CTC is y = 0.4292x + 0.1482; 3) Testing of the system under test; The ΔF of the test system was determined using the same detection method as in step 2). 425 / F 500 The concentration of CTC in the test system is calculated using the curve from step 2).

2. The method for rapid detection of CTCs according to claim 1, characterized in that, The linear concentration range of CTC is 0-1 μmol / L, and the detection limit is 0.96 nmol / L.

3. The method for rapid detection of CTCs according to claim 1, characterized in that, In step 1), the temperature is controlled at 80°C, and the reaction is carried out at 200 rpm in the dark for 8 hours.

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