Doped polymer dot as well as preparation method and application thereof

Abstract

The invention discloses a doped polymer dot as well as a preparation method and application thereof, and the doped polymer dot Ru (at) Pdots is prepared by taking a derivative of hydrophobic bipyridine ruthenium as a doped dye and a polymer dot with a co-reactant as an inclusion through a nano precipitation method. A self-enhanced polymer point-Ru (at) Pdots is synthesized by introducing intramolecular electron transfer and intermolecular resonance energy transfer processes, the Ru (at) Pdots serve as a self-enhanced ECL probe, an ECL imaging array capable of being used for visual detection is prepared, nitrogen free radicals on side chains of the Ru (at) Pdots are consumed after iodine in a detection solution is oxidized, and therefore ECL of the Ru (at) Pdots is quenched. The method not only realizes visual detection of iodine content in natural seawater, but also provides thinking and possibility for detection of radioactive substances in nuclear pollution.

Description

Technical Field

[0001] The present invention relates to a polymer dot for high-throughput iodine ion detection, and in particular to a doped polymer dot and a preparation method and application thereof. Background Art

[0002] Although nuclear energy can provide large-scale electricity without producing greenhouse gases, the operation of nuclear power plants and potential nuclear accidents may release a large amount of radionuclides, causing great and irreversible damage to the global marine environment and biological health. If a large amount of radionuclides that have not been effectively treated, such as iodine-129 and iodine-131, are discharged into the ocean, these radioactive iodine isotopes will enter the ecosystem through the air or water, and then gradually accumulate in the food chain, thus threatening human health and even increasing the risk of cancer. Therefore, designing a method for rapid and accurate determination of iodine ions in the environment shows its great significance in the field of environmental public safety.

[0003] Electrochemiluminescence imaging (ECL) is a new type of visual detection technology that combines the advantages of biological imaging technology and ECL technology, and has the advantages of high throughput, high sensitivity, and convenient detection process. 2+ ) has excellent electrochemical stability and high ECL efficiency. It has been the most widely used luminophore since its ECL behavior was reported. However, enhancing the efficiency of its ECL luminophore simply by increasing the concentration of ruthenium bipyridine is very limited. Therefore, the design of luminophores with higher luminescence efficiency using ruthenium bipyridine has attracted widespread attention.

[0004] In recent years, some methods for iodine ion detection in the field of nuclear safety have been reported, such as ion chromatography (IC), inductively coupled plasma emission spectrometry (ICP-OES), X-ray fluorescence, etc. However, these methods are still limited by high cost, long detection time, low sensitivity, etc. in actual water source detection. The method we are involved in has greatly improved these problems. The sensitivity is improved by enhancing the luminescence efficiency of polymer dots, and the detection time is greatly saved by taking advantage of the fast detection speed of electrochemiluminescence. At the same time, the experimental instruments are simple, the detection cost is extremely low, and only simple pre-treatment is required for detection. Summary of the invention

[0005] In order to address the shortcomings of the above-mentioned technologies, the present invention provides a doped polymer dot and a preparation method and application thereof, synthesizes a high-luminescence-intensity, self-enhanced, doped polymer dot, and realizes high-throughput, visual, rapid and accurate detection of iodide ions through a homemade ECL imaging array combined with electrochemiluminescence imaging technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing doped polymer dots, using a hydrophobic bipyridine ruthenium derivative as a doping dye and polymer dots with their own co-reactants as inclusions, and preparing doped polymer dots Ru@Pdots by a nanoprecipitation method.

[0007] Preferably, the method comprises the following steps:

[0008] Step S1, synthesis of N-PFO: firstly, M1, M2, Pd(PPH3)4, and K2CO3 are dissolved in solution 1 to react to obtain a polymer solid M3, and then M3, diethylamine, and K2CO3 are dissolved in solution 2 to react to obtain a polymer solid N-PFO;

[0009] Step S2, synthesis of Ru(bpy)3[B(C6F5)4]2: mixing Ru(bpy)3Cl2·6H2O and Li[B(C6F5)4]2·nEt2O aqueous solutions dropwise under continuous stirring at room temperature, centrifuging the formed orange-red precipitate, washing, and drying overnight to obtain hydrophobic Ru(bpy)3[B(C6F5)4]2;

[0010] Step S3, preparation of Ru@Pdots: The synthesized polymer N-PFO, Ru(bpy)3[B(C6F5)4]2 and poly(styrene-maleic anhydride) are respectively prepared into tetrahydrofuran solutions and mixed evenly with tetrahydrofuran. The mixed solution is subjected to ultrasonic degassing and oscillation ultrasonic treatment, and the tetrahydrofuran in the solution is removed and the solution is concentrated to obtain a Ru@Pdots dispersion.

[0011] Preferably, the specific process of step S1 is: weigh a certain amount of M1, M2, Pd(PPH3)4, and K2CO3 respectively, dissolve them in a solution of toluene and water, then place the mixed solution in a Schlenk tube, and stir the reaction at 90-110° C. for 2-4 days under an argon atmosphere, and then purify the product to obtain a light orange polymer solid, namely M3;

[0012] A certain amount of M3, diethylamine, and K2CO3 were dissolved in a solution 2 mixed with tetrahydrofuran and N,N-dimethylformamide, and stirred in a Schlenk tube under an argon atmosphere at 90-110°C for 3-5 days. The final solid product was precipitated twice and purified to obtain an orange polymer solid, which was the final product N-PFO.

[0013] Preferably, in step S1: M1 is 2,2'-(9,9-bis(6-bromohexyl)-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane), M2 is 2,7-dibromo-9,9-bis(6-bromohexyl)-9H-fluorene, and M3 is poly-9,9-bis(6-bromohexyl)-9H-fluorene.

[0014] Preferably, in step S1: the mass ratio of M1, M2, Pd(PPH3)4, and K2CO3 is 10:10:1:100, the mass ratio of M3, diethylamine, and K2CO3 is 1:10:10, and the volume ratio of solution one and solution two is 4:1.

[0015] Preferably, the specific process of step S3 is: the synthesized polymers N-PFO, Ru(bpy)3[B(C6F5)4]2 and poly(styrene-maleic anhydride) are respectively configured into tetrahydrofuran solutions of the same concentration, a certain amount of the above three solutions are respectively mixed with tetrahydrofuran, the mixed solution is ultrasonically degassed for 4-6 minutes, and then quickly injected into 85-95mL of water, after oscillation and mixing, ultrasonicated for 2-4 minutes, and the tetrahydrofuran in the solution is removed by a rotary evaporator and the solution is concentrated to finally obtain a Ru@Pdots dispersion.

[0016] Preferably, in step S3, the three solutions are mixed with tetrahydrofuran in a volume ratio of 2:4:1.

[0017] A doped polymer dot obtained by the above preparation method.

[0018] An application of doped polymer dots, using the doped polymer dots as ECL luminescent bodies, to perform high-throughput imaging detection of iodide ions without the addition of external co-reactants.

[0019] Preferably, the polymer dots are mixed with a solution containing iodide ions and placed in an ECL imaging array, and an ECL signal can be obtained by applying a potential to achieve detection of iodide ions.

[0020] The present invention synthesizes self-enhanced polymer dots, Ru@Pdots, by introducing intramolecular electron transfer and intermolecular resonance energy transfer processes, and uses Ru@Pdots as self-enhanced ECL probes to make an ECL imaging array that can be used for visual detection. The iodine in the detection solution is oxidized and consumes the nitrogen free radicals on the side chain of Ru@Pdots, thereby quenching the ECL of Ru@Pdots. This method not only realizes the visual detection of iodine content in natural seawater, but also provides ideas and possibilities for detecting radioactive substances in nuclear pollution.

[0021] The purpose of the present invention is to provide a high-throughput, visual, rapid and accurate iodine ion detection method. Compared with the prior art, the present invention uses doped polymer dots with high luminescence efficiency as ECL luminophores, which greatly improves the detection efficiency and sensitivity. In addition, the method is simple to handle and has good radiation resistance, which is expected to provide a new idea for detecting radioactive iodine substances in the ocean. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The preparation principle diagram of the present invention: (A) Schematic diagram of the preparation of Ru@Pdots; (B) ECL imaging mechanism diagram between Ru@Pdots and I-.

[0023] Figure 2 The figure is a synthetic route diagram of N-PFO of the present invention.

[0024] Figure 3 This is the synthesis route diagram of Ru(bpy)3[B(C6F5)4]2 of the present invention.

[0025] Figure 4 Characterization diagrams of Ru@Pdots prepared according to an embodiment of the present invention: (A) TEM image of Ru@Pdots; (B) high-resolution TEM image of a single Ru@Pdot; (C) high-angle annular dark field image of Ru@Pdots and (D) mapping diagrams of C, (E) N, (F) O, (G) B, (H) Ru, and (I) F elements.

[0026] Figure 5 UV-visible absorption spectra of N-PFO Pdots, Ru@Pdots, and Ru(bpy)3[B(C6F5)4]2 prepared in the examples of the present invention.

[0027] Figure 6 The curve diagram of the product obtained in the embodiment of the present invention for iodine ion detection is as follows: (A) I - ECL curves with concentrations ranging from 0.04 to 8000 μM, (B) calibration curve; (C) ECL images with I-concentrations ranging from 0.0008 to 4 μM, (D) calibration curve, n=3.

[0028] Figure 7 This is a graph evaluating the anti-interference performance of the polymer dot-modified electrode according to an embodiment of the present invention.

[0029] Figure 8 This is a comparison diagram of the ECL intensity in a radiation environment and a non-radiation environment according to an embodiment of the present invention.

[0030] Fig. 9 The results of the iodine ion detection in seawater samples are compared between the embodiments of the present invention and the commercial kit, and the ECL imaging diagram is shown. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] In order to solve the disadvantage of low detection sensitivity, the present invention mixes two luminescent materials in an appropriate proportion to synthesize a polymer dot with high luminescence efficiency, which greatly improves the detection efficiency. In addition, the preparation process uses electrochemiluminescence, which combines electrochemistry with chemiluminescence, and has the advantages of low background, high sensitivity, strong controllability, fast analysis speed, and wide linear range. By combining electrochemiluminescence with bioimaging technology, a visual detection of iodine is performed, and the preparation of a homemade indium tin oxide porous electrode array is combined to achieve high-throughput detection of iodine. In addition, the luminescent material in the present invention is also tested for radiation resistance. The experimental results show that the material has good radiation resistance and has certain application value in the fields of marine environmental monitoring, nuclear safety, and cancer radiotherapy.

[0033] The present invention introduces a tertiary amine into the side chain of a commercial polymer: poly (9,9-dioctylfluorenyl-2,7-diyl) (PFO) to obtain N-PFO Pdots with a co-reactant. A large number of bipyridine ruthenium derivative molecules (Ru(bpy)3[B(C6F5)4]2) are encapsulated in the N-PFO Pdots as a carrier, and the ECL emission of ruthenium is greatly enhanced through the resonance energy transfer mechanism between the hydrophobic ruthenium derivative and the N-PFO molecule. The synthesized Ru@Pdots can show excellent ECL performance in PBS without the need for additional co-reactants. Note: PBS here refers to a phosphate buffer solution with a pH of 7.4.

[0034] Using this self-enhanced ECL probe and ECL imaging, I - Visual detection. Specifically, the Ru@Pdots modified on the electrode are first oxidized and deprotonated on the electrode. Then, the iodide ions in the solution are oxidized into iodide ion radicals on the electrode surface. The iodide ion radicals can quench the ECL of Ru@Pdots (i.e., weaken the ECL signal). The more iodine there is in the solution, the weaker the ECL signal is, and the brightness of the ECL imaging will gradually weaken.

[0035] The detection working principle is as follows: first, Ru@Pdots are modified on the electrode surface. Ru@Pdots are oxidized and deprotonated on the electrode. The nitrogen free radicals produced will be consumed by the oxidized iodine ion free radicals in the solution, resulting in the quenching of ECL. The iodine ion free radicals quench ECL, thereby realizing the detection of iodine ion concentration.

[0036] The detection method has a wide detection range and high sensitivity, and realizes the visual detection of iodine content in seawater samples. In addition, after the probe is irradiated, its ECL intensity does not change, which proves that the proposed method has potential application value in marine environmental monitoring, nuclear radiation pollution and biological health.

[0037] Example:

[0038] Preparation of doped polymer dots Ru@Pdots, such as Figure 1 As shown:

[0039] Synthesis of N-PFO: Figure 2 As shown, first, 111.6 mg of M1, 97.5 mg of M2, 17.3 mg of Pd(PPH3)4 and 207.3 mg of K2CO3 were taken respectively, dissolved in a mixed solution of 4 ml of toluene and 1 ml of H2O, and then the solution was placed in a Schlenk tube and stirred at 100°C for 3 days under an argon atmosphere. Subsequently, the product was purified twice with methanol (adding sufficient cold methanol and stirring gently until the polymer was completely precipitated, discarding the supernatant, and then drying the precipitate in an oven at 98 degrees), and finally a light orange polymer solid was obtained, namely M3. Subsequently, 0.16 mM of M3, 16 mM of diethylamine and 221.1 mg of K2CO3 were dissolved in a mixed solution of 16 mL of tetrahydrofuran (THF) and 4 mL of N,N-dimethylformamide (DMF), and stirred at 100°C for 4 days in a Schlenk tube under an argon atmosphere. Finally, the final solid product was precipitated twice with methanol (adding sufficient cold methanol and stirring gently until the polymer was completely precipitated, and the supernatant was discarded), and an orange polymer solid was obtained by purification, which was the final product N-PFO.

[0040] Among them, M1 is 2,2'-(9,9-bis(6-bromohexyl)-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane), M2 is 2,7-dibromo-9,9-bis(6-bromohexyl)-9H-fluorene, and M3 is poly-9,9-bis(6-bromohexyl)-9H-fluorene.

[0041] Synthesis of Ru(bpy)3[B(C6F5)4]2: Figure 3As shown, an aqueous solution of Ru(bpy)3Cl2·6H2O (74.9 mg, 0.1 mmol) and Li[B(C6F5)4]2·nEt2O (217.2 mg, 0.1 mmol) was mixed dropwise under continuous stirring at room temperature. The orange-red precipitate formed was centrifuged and washed (10000 r centrifugation for 10 minutes and washed with triple distilled water), and the final precipitate was dried at 80°C overnight to obtain hydrophobic Ru(bpy)3[B(C6F5)4]2.

[0042] Preparation of Ru@Pdots: The synthesized polymer N-PFO, Ru(bpy)3[B(C6F5)4]2 and poly(styrene-maleic anhydride) (PSMA) were prepared into 10 mg / mL -1 THF solution, take a 15mL centrifuge tube, add 100μL 10mgmL -1 N-PFO solution, 200 μL 10 mg mL -1 Ru(bpy)3Cl2·6H2O solution, 50μL 10mgmL -1 PSMA solution and 9.65 mL of tetrahydrofuran were mixed. The mixed solution was ultrasonically degassed for 5 minutes and then quickly injected into 90 mL of water. After oscillation and mixing, it was ultrasonicated for 3 minutes. Finally, the tetrahydrofuran in the solution was removed by a rotary evaporator and the solution was concentrated to obtain a concentration of 50 μg mL - 1 Ru@Pdots dispersion.

[0043] Characterization of Ru@Pdots, such as Figure 4 As shown:

[0044] The polymer dots Ru@Pdots were finally synthesized by nanoprecipitation method and the transmission electron microscopy (TEM) ( Figure 4 AB) and its high-angle annular dark field image ( Figure 4 C) It can be seen that Ru@Pdots are spherical particles with a diameter of about 100 nm. High-angle annular dark field (HAADF) image ( Figure 4 C) and energy dispersive x-ray spectroscopy (EDS) ( Figure 4 DI) showed that C( Figure 4 D)、N( Figure 4 E), O( Figure 4 F), B( Figure 4 G), Ru( Figure 4 H) and F( Figure 4 I) The clear distribution of elements further confirms the effective doping of Ru(bpy)3[B(C6F5)4]2 in Ru@Pdots.

[0045] After N-PFO was doped with Ru(bpy)3[B(C6F5)4]2, the synthesized Ru@Pdots were analyzed by UV-visible spectroscopy (e.g. Figure 5 As shown in the figure, the synthesized Ru@Pdots have two obvious absorption peaks at 289nm and 39nm. Among them, the absorption peak at 289nm can be attributed to the fusion of the absorption peak of N-PFO Pdots at 281nm and the absorption peak of Ru(bpy)3[B(C6F5)4]2 at 298nm. The absorption peak at 391nm comes from the fusion of the absorption peak of N-PFO Pdots at 387nm and the absorption peak of Ru(bpy)3[B(C6F5)4]2 at 451nm, which also proves the successful doping of the two materials.

[0046] The prepared Ru@Pdots were applied to iodine ion detection:

[0047] For ECL detection, a platinum wire electrode is used as the counter electrode, a silver / silver chloride electrode is used as the reference electrode, a luminophore is modified on a glassy carbon electrode (working electrode), different concentrations of potassium iodide are dissolved in 0.1M, pH 7.4 PBS, and the ECL intensity is directly detected by an ECL analysis system. Different from ECL detection, ECL imaging uses an indium tin oxide (ITO) glass electrode as the working electrode, and a porous sticker is pasted on the ITO electrode to make an ECL electrode array. Ru@Pdots are then modified in the array holes, and silver / silver chloride wire is used as the reference electrode, and platinum wire is used as the counter electrode. The images are taken using a homemade imaging system (camera: Chongqing Aopu UOP0600CSC, lens: Canon 50, EF1.2).

[0048] Under the optimized preparation conditions, Ru@Pdots were used as detection probes for the subsequent detection of iodide ions. Figure 6 As shown, for each concentration point, three parallel tests were conducted, and the average of the three values ​​was finally taken for plotting. The synthesized Ru@Pdots were first modified on a glassy carbon electrode for ECL detection of iodine ions. As the amount of iodine ions added to the system increased, the ECL intensity of Ru@Pdots gradually decreased ( Figure 6 A). This is because during the electrochemical oxidation process, iodine ions are oxidized to iodine free radicals, which consume the free radicals generated by the tertiary amine on the side chain of N-PFO, thereby quenching the ECL signal. In the range of 0.04μM-8000μM, the ECL intensity and the logarithmic value of the iodine ion concentration show a good linear relationship, and the detection limit (LOD) is 5nM ( Figure 6 B). Based on the high ECL signal intensity of Ru@Pdots, its application in iodine ion ECL imaging detection was further explored. The results showed that the imaging brightness of Ru@Pdots in the ECL imaging array also gradually weakened with the increase of iodine ion concentration ( Figure 6 C), and in the range of 0.0008μM-4μM, the ECL imaging intensity showed a good linear relationship with the logarithmic value of the iodide ion concentration, and the LOD was 0.1nM ( Figure 6 D). The above results show that the application of Ru@Pdots in iodide ion detection not only exhibits a wide detection range and high sensitivity, but also shows a lower detection limit in high-throughput ECL imaging detection, which is of great significance for the development of high-throughput visual monitoring of iodide ions.

[0049] In order to explore the specificity of the ECL sensor, the Ru@Pdots in PBS blank solution ( Figure 7 a) and 0.08 mM interfering ions (Cl - Br - 、NO3 - 、SO4 2- 、CO3 2- 、HCO3 - 、H2PO4 - and HPO4 2- ) of the mixed solution ( Figure 7 b), 0.08 mM iodine ion solution ( Figure 7 c), and a solution of 0.08 mM iodine ion plus interfering ions ( Figure 7 d) The difference in ECL intensity. Figure 7 As shown, Ru@Pdots in the presence of interfering ions ( Figure 7 b) and blank solution ( Figure 7 a) is basically the same, but in the presence of 0.08 mM I - ( Figure 7 c) solution and 0.08 mM I - ( Figure 7 The mixed solution of d) has an obvious ECL quenching effect, and the intensity of the two is almost the same. The above results show that the ECL sensor has a high specificity for iodine ion detection, which provides a possibility for the rapid and accurate detection of iodine in complex matrices in the environment.

[0050] In addition, Ru@Pdots were modified on the polished and cleaned glassy carbon electrodes, and the electrodes were divided into two groups. One group was placed in a glass container (0.7L) containing 0.3MBq I-131 and irradiated as the experimental group, while the other group was placed in a glass container without I-131 as the control group. After the two groups of electrodes were allowed to stand at room temperature for 5 minutes, the ECL signals of the two groups of modified electrodes were detected in PBS with a concentration of 0.1M and pH 7.4. Figure 8As shown, the ECL intensity of Pdots (with) treated with a radioactive environment and Pdots (without) not treated with a radioactive environment in PBS was compared. It can be seen that there is almost no difference in the ECL of the two, indicating that the ECL intensity of the Ru@Pdots of the present invention is not affected by the radioactive environment, proving the significance of this method for radioactive environment monitoring.

[0051] On this basis, the iodine ion content of the offshore waters at three locations (marked locations) was analyzed, and the test results were compared with those of the commercial kits (such as Fig. 9 As shown). The three seawater samples were marked as 1, 2, and 3, respectively, and the method proposed in the present invention was used to detect them. It can be seen from the bar graph that the detection results of the proposed method (ECL) and the detection using the kit (Kit) are consistent. In addition, ECL imaging detection was also performed using an ITO imaging array. The results showed that the method of the present invention has high accuracy, and the ECL luminophore, that is, the doped polymer dots (Ru@Pdots) synthesized by the present invention, has the potential to be applied to the quantitative detection of iodide ions in actual seawater samples.

[0052] The present invention introduces intramolecular electron transfer and intermolecular resonance energy transfer processes when synthesizing luminescent materials, greatly enhancing the luminous efficiency of the luminophore. The method of electrochemiluminescence imaging is used, combining the advantages of electrochemistry, chemiluminescence, and biological imaging, showing a wide detection range and high sensitivity, while also being able to perform high-throughput, visual detection. The detection accuracy of the present invention is high, and after radiation resistance testing, it is proved that the method is not affected by the radiation environment, providing the possibility of monitoring iodine in a radiation environment.

[0053] The above implementation modes are not limitations of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the scope of the technical solution of the present invention also belong to the protection scope of the present invention.

Claims

1. A method for preparing doped polymer dots, characterized in that: Doped polymer dots Ru@Pdots were prepared by nanoprecipitation method using hydrophobic bipyridine ruthenium derivatives as doping dyes and polymer dots with co-reactants as inclusions.

2. The method for preparing doped polymer dots according to claim 1, wherein: The method comprises the following steps: Step S1, synthesis of N-PFO: firstly, M1, M2, Pd(PPH3)4, and K2CO3 are dissolved in solution 1 to react to obtain a polymer solid M3, and then M3, diethylamine, and K2CO3 are dissolved in solution 2 to react to obtain a polymer solid N-PFO; Step S2, synthesis of Ru(bpy)3[B(C6F5)4]2: mixing Ru(bpy)3Cl2·6H2O and Li[B(C6F5)4]2·nEt2O aqueous solutions dropwise under continuous stirring at room temperature, centrifuging the formed orange-red precipitate, washing, and drying overnight to obtain hydrophobic Ru(bpy)3[B(C6F5)4]2; Step S3, preparation of Ru@Pdots: The synthesized polymer N-PFO, Ru(bpy)3[B(C6F5)4]2 and poly(styrene-maleic anhydride) are respectively prepared into tetrahydrofuran solutions and mixed evenly with tetrahydrofuran. The mixed solution is subjected to ultrasonic degassing and oscillation ultrasonic treatment, and the tetrahydrofuran in the solution is removed and the solution is concentrated to obtain a Ru@Pdots dispersion.

3. The method for preparing doped polymer dots according to claim 2, wherein: The specific process of step S1 is: weigh a certain amount of M1, M2, Pd(PPH3)4, and K2CO3 respectively, dissolve them in a solution of toluene and water, then place the mixed solution in a Schlenk tube, and stir the reaction at 90-110° C. for 2-4 days under an argon atmosphere, and then purify the product to obtain a light orange polymer solid, namely M3; A certain amount of M3, diethylamine, and K2CO3 were dissolved in a solution 2 mixed with tetrahydrofuran and N,N-dimethylformamide, and stirred in a Schlenk tube under an argon atmosphere at 90-110°C for 3-5 days. The final solid product was precipitated twice and purified to obtain an orange polymer solid, which was the final product N-PFO.

4. The method for preparing doped polymer dots according to claim 3, wherein: In the step S1: M1 is 2,2'-(9,9-bis(6-bromohexyl)-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane), M2 is 2,7-dibromo-9,9-bis(6-bromohexyl)-9H-fluorene, and M3 is poly-9,9-bis(6-bromohexyl)-9H-fluorene.

5. The method for preparing doped polymer dots according to claim 3, wherein: In the step S1: the mass ratio of M1, M2, Pd(PPH3)4, and K2CO3 is 10:10:1:100, the mass ratio of M3, diethylamine, and K2CO3 is 1:10:10, and the volume ratio of solution 1 and solution 2 is 4:

1.

6. The method for preparing doped polymer dots according to claim 2, wherein: The specific process of step S3 is as follows: the synthesized polymers N-PFO, Ru(bpy)3[B(C6F5)4]2 and poly(styrene-maleic anhydride) are respectively configured into tetrahydrofuran solutions with the same concentration, a certain amount of the above three solutions are respectively mixed with tetrahydrofuran, the mixed solution is ultrasonically degassed for 4-6 minutes, and then quickly injected into 85-95mL of water, after oscillation and mixing, ultrasonicated for 2-4 minutes, and the tetrahydrofuran in the solution is removed by a rotary evaporator and the solution is concentrated to finally obtain a Ru@Pdots dispersion.

7. The method for preparing doped polymer dots according to claim 6, wherein: In step S3, the three solutions are mixed with tetrahydrofuran in a volume ratio of 2:4:

1.

8. A doped polymer dot obtained by the preparation method of claim 1.

9. A use of the doped polymer dots as claimed in claim 8, characterized in that: Using doped polymer dots as ECL luminophores, high-throughput imaging detection of iodide ions was performed without the addition of co-reactants.

10. The use of the doped polymer dots according to claim 9, characterized in that: The polymer dots are mixed with a solution containing iodide ions and placed in an ECL imaging array. By applying a potential, an ECL signal can be obtained to detect iodide ions.

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