Supramolecular fluorescent probe and application thereof

Abstract

The invention discloses a supramolecular fluorescent probe which is prepared from ring-opened cucurbituril and cationic pink through an inclusion reaction, and the molar ratio of the ring-opened cucurbituril to the cationic pink is 1: 1. According to the invention, ring-opened cucurbituril and cationic pink are subjected to supramolecular assembly, and a flexible cavity of the ring-opened cucurbituril is utilized to carry out torsion restriction on the cationic pink based on the principle of size adaptation, so that the intermolecular charge transfer emission state of the cationic pink is enhanced; the supramolecular fluorescent probe can generate extremely strong orange-red fluorescence under the action of the fluorescent probe, can realize dual-mode detection of ultraviolet visible light and fluorescence of hypochlorous acid anions, has high sensitivity and extremely strong anti-interference capability, and can be widely applied to the fields of biomedicine, environmental monitoring, food safety and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of new materials, and specifically relates to a supramolecular fluorescent probe and a preparation method and application thereof. Background Art

[0002] Hypochlorous acid (HOCl) is an efficient and powerful oxidant that can eliminate bacteria, viruses and other harmful substances. As a mild disinfectant, HOCl is widely used in drinking water treatment, food processing, medical and environmental sanitation, especially in various public places. However, excessive HOCl can damage the human body, leading to a variety of diseases, including coronary artery disease, Alzheimer's disease and kidney disease (Sensors and Actuators B: Chemical 284 (2019) 23-29). Therefore, it is necessary to develop a highly selective method for hypochlorite detection. Traditional methods for hypochlorite detection include titration, spectral analysis, electrochemical analysis, chromatography and colorimetry. However, these methods have the disadvantages of limited sensitivity and selectivity, time-consuming operation and high equipment requirements (ACS Applied Materials & Interfaces 11 (17) (2019) 15298-15305). There is an urgent need to develop a more sensitive supramolecular fluorescent probe.

[0003] Cationic pink is an important organic dye. Because of its bright color and excellent dyeing performance, it has a wide range of applications and in-depth research background in the textile printing and dyeing industry and biomedical fields. However, the molecular structure of cationic pink in aqueous solution tends to be more stable localized excited state (LE state). Its electron donor and acceptor are partially twisted, which causes the HOMO-LUMO orbital to separate, resulting in electron decoupling, which manifests as a relatively weak red fluorescence in aqueous solution. At present, existing studies on regulating twisted intermolecular charge transfer include changing the solvent type and increasing the solution viscosity, but they lack good water dispersibility and cell imaging potential.

[0004] Acyclic cucurbituril (ACB) is a new type of supramolecular host designed and synthesized by the Isaacs group in 2012, combining the characteristics of cucurbituril and pillar aromatics. Unlike traditional cucurbituril, it has a flexible and variable C-shaped cavity, which is easy to chemically modify on the terminal aromatic wall. In addition, the negatively charged carbonyl port of the open-ring cucurbituril has a strong affinity for cationic compounds, which is conducive to better recognition and assembly of guest molecules (Chemical Science 15 (14) (2024) 5163-5173). The hydrophobic cavity of the open-ring cucurbituril has an orthogonal configuration that restricts the electron donor and acceptor of the guest molecule to twist to 90°. This spatial confinement effectively hinders the transition of certain dye molecules from the intramolecular charge transfer (ICT) emission state to the non-radiative twisted intramolecular charge transfer (TICT) state in aqueous solution, thereby promoting fluorescence enhancement (Analytica Chimica Acta 1254 (2023) 341095).

[0005] A supramolecular fluorescent probe was prepared by supramolecular assembly of open-ring cucurbituril and cationic rhodamine, which achieved dual-mode detection of hypochlorite and had the ability of cell imaging and detection of real water samples. This method has not been reported before. Summary of the invention

[0006] The present invention provides a supramolecular fluorescent probe based on open-ring cucurbituril and cationic rosin, which has the advantages of good water dispersibility, low toxicity and high sensitivity, can realize dual-mode detection of hypochlorite, and also has the function of staining and imaging cells.

[0007] To achieve the above purpose, the present invention places an equimolar ratio of open-ring cucurbituril and cationic rosin in pure water, stirs and dissolves them at room temperature, and then stirs in the dark for inclusion reaction for 1 to 48 hours. The reaction product is purified and freeze-dried to obtain a supramolecular fluorescent probe (the structural formula is as follows);

[0008]

[0009] The structural formula of the open-ring cucurbituril is selected from the following:

[0010]

[0011] Wherein R is selected from -(CH2)3SO3Na, -O(CH2)2PO3Na2.

[0012] The structural formula of the cationic pink is as follows:

[0013]

[0014] The purification is carried out by dialysis or membrane filtration.

[0015] The drying is freeze drying, vacuum drying or spray drying.

[0016] Another object of the present invention is to apply the supramolecular fluorescent probe to the dual-mode detection of hypochlorite anions using ultraviolet or fluorescence.

[0017] The absorbance of the UV-visible absorption spectrum was taken at the maximum absorption wavelength of 535 nm; the excitation wavelength of the fluorescence spectrum was 536 nm, and the emission wavelength was 586 nm.

[0018] The detection limit of the supramolecular fluorescent probe of formula I is 0.08 mg / L under ultraviolet absorption spectrum and 0.012 mg / L under fluorescence spectrum; the detection limit of the supramolecular fluorescent probe of formula II is 0.025 mg / L under ultraviolet absorption spectrum and 0.015 mg / L under fluorescence spectrum.

[0019] The supramolecular fluorescent probe of the present invention has the ability to detect hypochlorite ions in cells and hypochlorite ions in real water samples.

[0020] The invention also provides a portable test strip, which contains the supramolecular fluorescent probe.

[0021] The test paper used to prepare the test paper is strip-shaped qualitative filter paper, the concentration of the staining solution (supramolecular fluorescent probe) is 1 mg / mL, the staining time is 24 h, and the detection limit is 0.25 mg / L.

[0022] The present invention focuses on acyclic cucurbiturils (ACBs), which have a unique structure and are constructed from a glycoluril tetramer unit and two aromatic ends carrying anionic sulfonate groups. This special structural characteristic is remarkable. On the one hand, it creates an adjustable C-shaped cavity that can be fine-tuned according to the size difference of the guest molecule, and on the other hand, it greatly improves its water solubility. In terms of interaction with guest molecules, its aromatic end can effectively carry out π-π interaction, and the polycarbonyl structure can form multiple hydrogen bonds with the guest. Based on the above characteristics, the open-ring cucurbiturils exhibit excellent inclusion capacity for neutral molecules or cations. This characteristic is of extremely critical significance in the technical solution and application scenarios of the present invention, and can be used as a core element for constructing various functional materials or for use in related technical fields such as molecular recognition and separation.

[0023] The open-ring cucurbituril in the present invention is prepared according to the method described in the existing literature (Nat. Chem., 2012, 4: 503).

[0024] The beneficial technical effects of the present invention are:

[0025] The supramolecular fluorescent probe based on self-assembly of open-ring cucurbituril and cationic rutin provided by the present invention is simple to prepare, safe and efficient. The supramolecular fluorescent probe is applied to the detection of hypochlorite and can not only realize dual-mode detection of ultraviolet and fluorescence, but also has the characteristics of high sensitivity, fast response speed, strong anti-interference ability and good biocompatibility. The prepared test paper can also realize visual detection. The supramolecular fluorescent probe of the present invention can be applied to the fields of biomedicine, environmental science, chemical analysis and material science. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a comparative analysis of the H NMR spectra of the cationic peach red, the inclusion compound, and the open-ring cucurbituril M1 in Example 1, and the spectra from top to bottom are the cationic peach red, the inclusion compound, and the open-ring cucurbituril M1;

[0027] Figure 2 2D-ROESY spectrum analysis diagram of the inclusion compound in Example 1;

[0028] Figure 3 This is a comparative analysis of the H NMR spectra of the cationic peach red, the inclusion complex, and the open-ring cucurbituril M2 in Example 2, and the spectra from top to bottom are open-ring cucurbituril M2, the inclusion complex, and the cationic peach red;

[0029] Figure 4 2D-ROESY spectrum analysis diagram of the inclusion compound in Example 2;

[0030] Figure 5 The infrared spectra of the inclusion complex in Example 1 are comparative analysis diagrams; (a) inclusion complex; (b) physical mixture; (c) cationic pink; (d) open-ring cucurbituril M1;

[0031] Figure 6 The infrared spectra of the inclusion complex in Example 2 are comparative analysis diagrams; (a) inclusion complex; (b) physical mixture; (c) cationic pink; (d) open-ring cucurbituril M2;

[0032] Figure 7 The X-ray diffraction spectra of the inclusion complex in Example 1 are compared and analyzed; (a) inclusion complex; (b) physical mixture; (c) cationic pink; (d) open-ring cucurbituril M1;

[0033] Figure 8 The X-ray diffraction spectra of the inclusion complex in Example 2 are compared and analyzed; (a) inclusion complex; (b) physical mixture; (c) cationic pink; (d) open-ring cucurbituril M2;

[0034] Fig. 9The UV-visible spectrophotometry and fluorescence detection results of the open-ring cucurbituril M1 and the cationic pink inclusion complex in Example 3, wherein Figure A is a UV-visible absorption spectrum, Figure B is a linear fitting diagram of hypochlorite concentration (0-17.5 mg / L) and absorbance value; Figure C is a fluorescence spectrum diagram, and Figure D is a linear fitting diagram of hypochlorite concentration (0-4 mg / L) and fluorescence intensity;

[0035] Fig.10 The UV-visible spectrophotometry and fluorescence detection results of the open-ring cucurbituril M2 and cationic pink inclusion complex in Example 3, wherein Figure A is a UV-visible absorption spectrum, Figure B is a linear fitting diagram of hypochlorite concentration (0.08-10 mg / L) and absorbance value; Figure C is a fluorescence spectrum, and Figure D is a linear fitting diagram of hypochlorite concentration (0-10 mg / L) and fluorescence intensity;

[0036] Fig.11 The figure is a test result of the anti-interference ability of the open-ring cucurbituril M1 and the cationic pink inclusion complex in Example 4 after adding different interfering substances in the hypochlorite detection application;

[0037] Fig.12 Schematic diagram of the imaging of the open-ring cucurbituril M1 and the cationic rosin inclusion complex in cells in Example 5. In the figure, APFG is rosin + cells, ACBs@APFG is the open-ring cucurbituril and cationic rosin inclusion complex + cells, and ACBs@APFG ClO - (5μM) is the open-ring cucurbituril and cationic peach red inclusion complex + cells + 5μmol / L sodium hypochlorite, ACBs@APFGClO - (10μM) is the open-ring cucurbituril and cationic rutin inclusion complex + cells + 10μmol / L sodium hypochlorite

[0038] Fig.13 Schematic diagram of the color development of the test paper under visible light (right figure) and fluorescence (left figure) in Example 6;

[0039] Fig.14 It is a linear relationship diagram between RGB value and concentration of sodium hypochlorite solution under visible light;

[0040] Fig.15 This is the mass spectrometry mechanism diagram of the supramolecular fluorescent probe detecting hypochlorite in Example 7. DETAILED DESCRIPTION

[0041] The technical scheme of the present invention is further described in detail below through examples, but the content of the present invention is not limited thereto. The methods in the present examples are conventional methods unless otherwise specified, and the materials and reagents used are obtained from commercial channels or prepared according to conventional methods unless otherwise specified;

[0042] Example 1: Preparation of the inclusion complex of open-ring cucurbituril M1 and cationic pink

[0043] 1 mmol of open-ring cucurbituril M1 was placed in 8 mL of ultrapure water, and after stirring and dissolving at room temperature, 1 mmol of cationic rutin was slowly added to the aqueous solution, and after the addition of cationic rutin was completed, stirring was continued for 24 hours under light-proof conditions. After the reaction was completed, the reaction product was placed in a dialysis bag with a molecular weight cutoff of 500 Da and dialyzed for 48 hours to effectively remove the free cationic rutin. Finally, the dialyzed product was freeze-dried to obtain a powdery inclusion complex of open-ring cucurbituril M1 and cationic rutin;

[0044] The structural formula of the open-ring cucurbituril M1 is as follows:

[0045]

[0046] The results of the comparative analysis of the H NMR spectra of the above-prepared inclusion complex are as follows: Figure 1 As shown in FIG. 1 , the reason why the proton (H-8 to 16) peak of the N-(2-chloroethyl)-N-methylaniline unit of the cationic peach red undergoes a high-field shift is the shielding effect of the open-ring cucurbituril cavity. On the other hand, the deshielding effect of the open-ring cucurbituril causes the protons of H-1 and 2 to undergo a front-field shift, while the proton peaks of the remaining parts remain relatively unchanged. The 2D-ROESY spectrum analysis diagram of the inclusion complex is shown in FIG. Figure 2 From the figure, it can be seen that H-4, H-5, H-6, and H-8 on the cationic peach red have significant correlation signals with the H-a', H-b', H-c', and Hg hydrogen protons inside the open-ring cucurbituril M1 cavity. These results all indicate the formation of inclusion complexes.

[0047] The infrared spectra of the inclusion complex, open-ring cucurbituril M1, cationic pink, and the physical mixture of open-ring cucurbituril M1 and cationic pink (mixed in a ratio of 1:1, ground and mixed) prepared in this example are shown in FIG. Figure 5 , powder X-ray diffraction comparison diagram is shown in Figure 8 , it can be seen from the figure that the X-ray diffraction spectrum and infrared spectrum of the prepared inclusion complex are significantly different from those of the cationic rosin itself, and are different from the physical mixture of the cationic rosin and the open-ring cucurbituril M1, thus proving that the inclusion complex has been successfully prepared.

[0048] Example 2: Preparation of the inclusion complex of open-ring cucurbituril M2 and cationic pink

[0049] Take 1mmol of open-ring cucurbituril M2 and place it in 8mL of ultrapure water. After stirring and dissolving at room temperature, 1mmol of cationic rutin is slowly added to the above aqueous solution. After the addition of cationic rutin is completed, stirring is continued for 24 hours under light-proof conditions. After the reaction is completed, the reaction product is placed in a dialysis bag with a molecular weight cutoff of 500Da and dialyzed for 48 hours to effectively remove the free cationic rutin. Finally, the dialyzed product is freeze-dried to obtain a powdery inclusion complex of open-ring cucurbituril M2 and cationic rutin.

[0050] The structural formula of the open-ring cucurbituril M2 is as follows:

[0051]

[0052] The results of the comparative analysis of the H NMR spectra of the inclusion complex prepared above are as follows: Figure 3 As shown in FIG. 1 , the reason why the proton peak (H-8 to 16) of the N-(2-chloroethyl)-N-methylaniline unit of the cationic pink is shifted to a high field is the shielding effect of the open-ring cucurbituril cavity, while the proton peaks of the remaining parts remain relatively unchanged, indicating the formation of an inclusion complex; the 2D-ROESY spectrum analysis of the inclusion complex is shown in FIG. Figure 4 As shown, H-8, H-10, and H-12 on the cationic cucurbitacin have significant correlation signals with the H-a', H-b', H-c', and Hg hydrogen protons inside the open-ring cucurbituril M2 cavity. Therefore, the formation of the inclusion complex was further determined based on 2D-ROESY.

[0053] The infrared spectra of the inclusion complex, the open-ring cucurbituril M2, the cationic pink, and the physical mixture of the open-ring cucurbituril M2 and the cationic pink prepared in this example are shown in FIG. Figure 6 , powder X-ray diffraction comparison diagram is shown in Figure 8 As can be seen from the figure, the X-ray diffraction pattern and infrared spectrum of the prepared inclusion complex are significantly different from those of the cationic rosin itself, and are different from the physical mixture of the cationic rosin and the open-ring cucurbituril M2, so it can be confirmed that the inclusion complex has been successfully prepared.

[0054] Example 3: Determination of detection limit of supramolecular fluorescent probe

[0055] 1. Transfer 700 μL of acetic acid-sodium acetate buffer (0.1 M, pH = 4.0), 50 μL of the inclusion complex of open-ring cucurbituril M1 and cationic pink (1 mg / mL) into a 15 mL centrifuge tube, incubate at room temperature for 30 min, then add sodium hypochlorite solution of different concentrations to the incubated solution, and incubate the mixed solution at room temperature for 10 min;

[0056] The incubated solution was detected by UV-Vis spectrophotometry. The absorbance was measured at a wavelength of 535 nm. The sodium hypochlorite concentration was used as the horizontal axis and the absorbance was used as the vertical axis. The linear relationship between the sodium hypochlorite concentration and the absorbance was obtained. The results are shown in Fig. 9 A, 9B;

[0057] The fluorescence intensity of the incubated solution was measured at an excitation wavelength of 536 nm and an emission wavelength of 586 nm. The linear relationship between the sodium hypochlorite concentration and the absorbance was obtained with the sodium hypochlorite concentration as the abscissa and the fluorescence intensity as the ordinate. The results are shown in Fig. 9 C, 9D;

[0058] Fig. 9 The results showed that the detection limit of open-ring cucurbituril M1 and cationic rutin inclusion complex was 0.08 mg / L by UV-visible spectrophotometry and 0.012 mg / L by fluorescence spectroscopy.

[0059] 2. The detection limit determination method of the open-ring cucurbituril M2 and cationic peach red inclusion complex is the same as step 1. The results are shown in Fig.10 The results showed that the detection limit of open-ring cucurbituril M2 and cationic rutin inclusion complex was 0.025 mg / L by UV-visible spectrophotometry and 0.015 mg / L by fluorescence spectroscopy.

[0060] Example 4: Supramolecular fluorescent probe specific detection experiment

[0061] 1. Add 0.02 mg / L of metal ions (Na+, Mg, Ca) to 2 mL of the inclusion complex of open-ring cucurbituril M1 and cationic peach red (1 mg / mL) respectively. 2+ 、Zn 2+ 、Co 2+ 、Al 3+ 、Na + or K + ), anion (SO4 2- PO4 2- 、CO3 2- 、SO3 2- , Cl - Br - ,I - 、NO3 - 、NO2 - 、CO3 2- 、NO3 - 、HCO3 - 、SO3 2- 、HPO4 2- , Cl - ,I - Br - IO3 - BrO3 -、H2PO4 - or HPO4 - ), other possible interferences GSH and H2O2, incubate at room temperature for 10 minutes, measure the fluorescence intensity at 536nm excitation wavelength and 586nm emission wavelength, then add 0.02mg / L sodium hypochlorite and measure the fluorescence intensity again. The results are as follows Fig.11 As shown, the results show that the inclusion complex of open-ring cucurbituril M1 and cationic pink has high selectivity and anti-interference ability for the detection of hypochlorite.

[0062] 2. The detection method of the inclusion complex of open-ring cucurbituril M2 and cationic peach red is the same as above. The results show that the inclusion complex of open-ring cucurbituril M2 and cationic peach red has high selectivity and anti-interference ability for the detection of hypochlorite.

[0063] Example 5: Cellular imaging detection experiment of the inclusion complex of open-ring cucurbituril and cationic rosin

[0064] Dissolve 20 μL in DMEM medium at a concentration of 1×10 -4 After incubating HeLa cells or LO2 cells with the inclusion complex of open-ring cucurbituril M1 and cationic rosin at 37°C and 5% CO2 for 12 hours, sodium hypochlorite with a final concentration of 5μM and 10μM was added to the cells respectively. After incubation for 2 hours, the cells were washed 5 times with PBS to remove the uninternalized free molecules and eliminate their interference. The cell imaging ability of the inclusion complex of open-ring cucurbituril and cationic rosin was studied using a confocal laser scanning microscope (CLSM, Eclips Ti, Nikon), and a control (APFG) of cationic rosin + cells was set.

[0065] Cell imaging results Fig.12 As shown, the experimental group with the addition of open-ring cucurbituril M1 and cationic peach red inclusion complex showed stronger red fluorescence than the group with the addition of cationic peach red. After the addition of hypochlorite, the red fluorescence gradually weakened. This result shows that hypochlorite can weaken the red fluorescence of the open-ring cucurbituril M1 and cationic peach red inclusion complex, so the inclusion complex has the ability to detect intracellular hypochlorite anions.

[0066] Example 6: Detection experiment of water sample by inclusion complex of open-ring cucurbituril and cationic pink

[0067] The real water sample tap water was taken from the laboratory of Kunming University of Science and Technology, and the river water was taken from Laoyu River in Chenggong District, Kunming City. Three different concentrations (0 mg / L, 1 mg / L, 3 mg / L) of sodium hypochlorite solution and 1 mg of the inclusion complex of open-ring cucurbituril M1 and cationic pink were added to the samples to be tested. After incubation at room temperature for 10 minutes, the fluorescence intensity was measured at an excitation wavelength of 536 nm and an emission wavelength of 586 nm, and the spike recovery rate was calculated; the results are shown in Table 1;

[0068] Table 1

[0069]

[0070] Example 7: Preparation and application of test strips

[0071] Place a strip of qualitative filter paper into a 1 mg / mL inclusion complex solution of open-ring cucurbituril and cationic pink, ensure that the filter paper is completely immersed in the dye solution, use tweezers to gently press the filter paper to fully soak it, and expel the air bubbles therein to ensure uniform dyeing. After the soaking is completed, use tweezers to take out the filter paper, place it flat on a glass plate and place it in a vacuum drying oven to dry for 24 hours, then take it out and place it in a light-proof sealed packaging bag for use;

[0072] Take the test paper out of the sealed package, quickly use a dropper to absorb an appropriate amount of the sample to be tested (sodium hypochlorite solution, concentration range 0-20mg / L), and drop it on the reaction area of ​​the test paper, ensuring that the liquid evenly covers the reaction area to avoid local drying or accumulation of liquid. The amount of drops should just wet the reaction area without overflowing, usually 2-3 drops (about 0.1-0.2mL). Place the test paper at room temperature (20-25℃) and avoid direct sunlight, and wait for the color reaction to stabilize, which usually takes 1-3 minutes. Do not shake or touch the test paper during this period to prevent uneven color from affecting judgment.

[0073] Place the colored test paper under natural light and use a smartphone to collect color images of filter paper strips with different concentrations ( Fig.13 The RGB value of the captured image was read using the image processing software Fiji Image J. The linear relationship between the RGB value and the concentration of the sodium hypochlorite solution is shown in Fig.14 ,From the results, it can be seen that the RGB value of the test paper has a strong linear correlation with the hypochlorite concentration. According to the fitting curve, the detection limit is 0.25 mg / L;

[0074] The filter paper strips with different concentrations were colored under a handheld ultraviolet lamp. The results are shown in Fig.13 As can be seen in the left picture, the color of the test paper changes from red to blue as the concentration of hypochlorite increases.

[0075] Example 8: Fluorescence quenching mechanism of the open-ring cucurbituril and cationic rosin inclusion complex

[0076] Prepare 3×10 -5: mol / L of open-ring cucurbituril and cationic rosin inclusion complex in acetate buffer (0.1 M, pH = 4.0), to which 3×10 -4 mol / L hypochlorite aqueous solution was vortexed for 2 h, and the possible quenching mechanism of hypochlorite was explored by high-resolution mass spectrometry.

[0077] The results are as follows Fig.15 The experiment showed that after the addition of hypochlorite, the molecular ion peak of APFG (m / z = 388.1473) disappeared, however, two new molecular ion peaks appeared after the double bond cleavage (m / z = 209.0971, [M+H] + =210.0840), (m / z=197.0607). Since the inclusion complex reacts in acetate buffer solution, acetate ions attack the aldehyde group, which is also confirmed by the molecular ion peak of (m / z=299.0880). In summary, we speculate that after the double bond of cationic rosin is oxidatively cleaved by hypochlorite, the structure of intermolecular electron transfer is destroyed, resulting in fluorescence quenching.

Claims

1. A supramolecular fluorescent probe, characterized in that: The invention is prepared by inclusion reaction of open-ring cucurbituril and cationic rosin, wherein the molar ratio of open-ring cucurbituril to cationic rosin is 1:

1.

2. The supramolecular fluorescent probe according to claim 1, characterized in that The structure of open-ring cucurbituril is as follows: Wherein R is selected from -(CH2)3SO3Na, -O(CH2)2PO3Na2.

3. The supramolecular fluorescent probe according to claim 1, characterized in that The structural formula of cationic pink is as follows:

4. The supramolecular fluorescent probe according to claim 1, characterized in that: Open-ring cucurbituril and cationic rosin in equal molar ratio are placed in pure water, stirred and dissolved at room temperature, and reacted for 1 to 48 hours in the dark. The reaction product is purified, concentrated and dried to obtain a supramolecular fluorescent probe.

5. Use of the supramolecular fluorescent probe according to claim 1 in detecting hypochlorite anions.

6. The use according to claim 5, characterized in that: Hypochlorite anion is detected by UV-visible spectrophotometry or fluorescence.

7. A test strip, characterized in that: The method comprises the supramolecular fluorescent probe according to claim 1.

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