A dual-excitation-dual-emission-dual-mode dynamic monitoring functional molecular probe, a preparation method and application thereof

Abstract

This invention relates to the field of organic small molecule material detection technology, specifically to a molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function, its preparation method, and its application. The molecular probe is reacted with ClO in a DMF-water solution. ‑ Increased concentration exhibits a dual-excitation, dual-emission fluorescence response and a dual-mode dynamic monitoring response based on a direct red-blue colorimetric change in the solution; with increasing alkalinity, its fluorescence emission exhibits an "on-off" dynamic response of first red shift and then blue shift, along with a dual-detection signal of gradually darkening red light in the solution; it also shows a similar response to low-concentration ClO₂. ‑ Forming a binary system for SCN ‑ SiO3 2‑ It exhibits red fluorescence emission "off-on" and reacts with high concentrations of ClO. ‑ The resulting binary system exhibits a dual-signal response to acidic environments, displaying both on-off blue fluorescence emission and a readily apparent colorimetric change, and provides rapid and sensitive detection. The molecular probe provided by this invention boasts advantages such as mild synthesis conditions and simple preparation, creating favorable conditions for its widespread application.

Description

Technical Field

[0001] This invention relates to the field of organic small molecule material detection technology, specifically to a method for detecting ClO based on red / blue fluorescence emission under dual excitation wavelengths and intuitive colorimetric signals. - Multifunctional molecular probes with dynamic detection characteristics in alkaline environments and their applications. Background Technology

[0002] Hypochlorous acid (HClO), as an important reactive oxygen species, plays a vital role in physiological and biological processes, such as regulating cell life cycle, enhancing antigen immunity, and promoting wound repair and tissue regeneration. However, various studies have shown that the HClO / ClO ratio in vivo... - Abnormal concentration levels can cause oxidative stress and tissue damage, leading to related diseases such as inflammation, neurodegeneration, cardiovascular disease, lung injury, rheumatoid arthritis, and even cancer. In daily life and work, hypochlorous acid and sodium hypochlorite, due to their strong oxidizing properties and low cost, are widely used as bleaching agents, disinfectants, and deodorizers in hospitals, hotels, food processing, sewage treatment, and fine chemical industries. In people's daily lives, 84 disinfectant, a very familiar and commonly used disinfectant, is widely used in homes and public places to disinfect germs. The main active ingredient of 84 disinfectant is sodium hypochlorite. While it is a convenient, highly effective chlorine-containing disinfectant, excessive use can produce chlorine gas, chlorates, and chlorites, leading to a sharp increase in chlorine levels in water, posing potential harm to aquatic organisms and the aquatic environment. Furthermore, if it enters the human body, it can cause serious harm, such as shortness of breath and edema. Therefore, the use of HClO / ClO... - The detection of ClO is of great significance in both environmental and physiological fields, and is crucial for understanding the concentration of ClO in actual water samples. - Monitoring is also extremely important.

[0003] Currently, HClO / ClO - There are many detection methods for HClO / ClO. One type relies on large-scale instrument analysis, such as atomic absorption spectrometry, atomic emission spectrometry, and inductively coupled plasma mass spectrometry. While these analytical methods can accurately detect HClO / ClO -While many methods exist for detecting HClO / ClO content, they often suffer from limitations such as expensive equipment, complex operation, long detection time, and high testing costs, restricting their application in practical environmental monitoring. Another type of detection method employs experimental analysis, such as titration, electrolytic analysis, and UV-Vis spectrophotometry. These methods typically require complex pretreatment and are cumbersome to operate, limiting their practical application. Compared to the above methods, fluorescent molecular detection is considered one of the ideal tools in environmental and biological research. Using fluorescent molecular probes for related detection requires relatively simple instruments and offers advantages such as a large detection range, rapid detection, simple operation, high portability, real-time detection, non-destructive testing, and low detection limits. It has been widely used in industrial and agricultural production, environmental engineering, medicine, and biological systems. Therefore, numerous methods containing HClO / ClO... - Fluorescent molecular probes with specific detection capabilities have been reported. However, most fluorescent molecular probes currently suffer from limitations such as complex synthesis, low yield, and long response time. Furthermore, due to the limitations of HClO / ClO... - It has the characteristics of strong oxidizing properties and short lifespan. Currently, it is simple to prepare, low in cost, and can be sensitively detected on-site. − Fluorescent molecular probes are struggling to meet the growing market demand, especially for ClO. - The development of molecular probes with dynamic detection capabilities is particularly challenging.

[0004] Furthermore, with rapid societal development, industrial and agricultural production processes that require specific acidic or alkaline environments to function properly necessitate efficient pH detection technology to track these processes, thereby improving product quality and work efficiency. Simultaneously, the direct discharge of untreated waste alkalis and acids into the soil during production can cause changes in the surrounding environment's acidity and alkalinity, posing significant harm to human production and daily life. Therefore, the industrial and agricultural sectors require sensitive analytical testing technologies to constantly monitor the discharge of acidic and alkaline solutions that could pollute the water and soil resources upon which people depend for survival. Fluorescent molecular probes, due to their high sensitivity, good selectivity, and ease of operation, have become powerful tools for detecting pH changes in various fields. However, most reported pH molecular probe fluorescence signals change with increasing / decreasing acidity / alkalinity, exhibiting a single signal change, while the demand for sensitive detection of dynamic pH changes in people's work and daily lives is increasing. Therefore, developing pH molecular probes that are easy to prepare, sensitive, rapid, and have a wide range of practical applications is an urgent need in various monitoring fields.

[0005] Imine Schiff bases are compounds with strong proton-complexing ability obtained through nucleophilic addition reactions. They are relatively sensitive to acidic environments. Introducing a C=N double bond functional group not only increases the conjugation of the molecule, but the nitrogen atom complexing with the proton can also induce sensitive changes in optical signals. Furthermore, the C=N functional group is also the HClO / ClO group. -Specific recognition sites, HClO / ClO - In its presence, the C=N double bond is oxidized and broken, leading to changes in the intramolecular electron cloud density and inducing sensitive optical signal changes, making it an ideal HClO / ClO - One of the building blocks for molecular probes. During the construction of pH-fluorescent molecular probes in alkaline environments, hydroxyl functional groups have attracted attention as deprotonation sites in alkaline environments. In recent years, diaminomaleitrile compounds, as flexible conjugated bridging units, have also received increasing attention in the construction of imine molecular probes due to their unique symmetrical diamino groups. However, currently, the construction of probes with diaminomaleitrile as the core bridging group, containing multiple hydroxyl and imine functional groups, and targeting ClO... - Molecular probes with dual excitation, dual emission, dual mode, and dynamic detection capabilities, suitable for acidic and alkaline environments, have not yet been developed. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a fluorescence-colorimetric dual-mode-dynamic detection of ClO based on the modulation of red / blue dual-color light emission conversion under dual-wavelength excitation. - The detection methods include: red fluorescence "on-off" dynamic detection in alkaline environments, blue fluorescence "on-off" detection in acidic environments, and red fluorescence "off-on" detection of SCN. - / SiO3 2- A multifunctional molecular probe, wherein the molecular probe is an asymmetric tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe.

[0007] This invention is achieved through the following technical solution: A multifunctional molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring properties, wherein the probe is an asymmetric tetramethyljulonidine-maleiconitrile-aminosalicylic acid molecule, and its structure is as follows: .

[0008] The molecular probe is easy to prepare and, based on the conversion of red and blue dual-color fluorescence signals, can achieve the detection of ClO₂. - Acidic and alkaline environments, SCN - and SiO3 2- Fast, accurate, and on-site testing.

[0009] Another object of the present invention is to provide a method for preparing the asymmetric tetramethylgurodin-maleitrile-aminosalicylic acid molecule, comprising the following steps: S1. Place 4-diethylaminosalicylic aldehyde into a round-bottom flask containing anhydrous ethanol, add diaminomaleitrile and glacial acetic acid in sequence, and heat to reflux for 4 hours; filter the mixture obtained from the reaction, wash with anhydrous ethanol, and dry to obtain a flesh-colored monoaminomaleitrile-diethylaminosalicylic compound. S2. The monoaminomaleitrile-diethylaminosalicylic acid compound obtained in step S1 is placed in a mixed solvent of N,N-dimethylformamide and anhydrous ethanol, and 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine and concentrated sulfuric acid are added. The mixture is heated to reflux for 6-8 hours. The resulting mixture is filtered, washed with anhydrous ethanol, and dried to obtain a dark purple tetramethyljulonidine-maleitrile-aminosalicylic acid molecule.

[0010] Further, in step S2, the molar ratio of the monoaminomaleitrile-diethylaminosalicylic acid compound and 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine is 1:1, the volume ratio of N,N-dimethylformamide and anhydrous ethanol in the mixed solvent is 1:4, the amount of the mixed solvent added is limited to 30 mL of mixed solvent for every 1 mmol of monoaminomaleitrile-diethylaminosalicylic acid compound, and the amount of concentrated sulfuric acid added is 100 μL of sulfuric acid for every 1 mmol of 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine.

[0011] The preparation reaction formula for the asymmetric tetramethyljulonidine-maleitrile-aminosalicylic acid molecule is as follows: .

[0012] A second objective of this invention is to provide the asymmetric tetramethyljulonidine-maleitrile-aminosalicylic acid molecule in ClO - Applications of detection.

[0013] Specifically, the molecular probe exhibits strong fluorescence emission near 655 nm in DMF-water solution; with ClO - As the concentration gradually increases, the fluorescence emission of this molecular probe gradually decreases and is eventually quenched at around 655 nm under excitation at 550 nm; under excitation at 400 nm, its fluorescence emission gradually increases at around 470 nm; under irradiation with a 365 nm ultraviolet (UV) lamp, with the increase of ClO... - As the concentration gradually increases, the red fluorescence of the molecular probe solution gradually weakens while the blue fluorescence gradually strengthens, endowing the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule with a pair of ClO₂. - The concentration change exhibits a dynamic dual-mode detection response with dual excitation-dual emission fluorescence and intuitive red-to-blue light colorimetric change in the solution.

[0014] A third objective of this invention is to provide the application of the aforementioned asymmetric tetramethylguronidin-maleitrile-aminosalicylic acid molecule in alkaline environment detection.

[0015] Specifically, the results are as follows: In a 50% DMF-water solution, as the NaOH concentration increases, the maximum fluorescence emission of the molecular probe near 655 nm first red-shifts to 662 nm, then blue-shifts to 632 nm, accompanied by a decrease in fluorescence emission intensity until quenching; under 365 nm ultraviolet (UV) irradiation, as the NaOH concentration increases, the red fluorescence of the tetramethyljulonidine-maleonitrile-aminosalicylic acid molecular probe solution gradually disappears. These results indicate that the tetramethyljulonidine-maleonitrile-aminosalicylic acid molecule exhibits a dynamic "on-off" fluorescence emission response to changes in alkaline environment and a dual-mode detection response of visual red fluorescence darkening under UV light.

[0016] A third objective of this invention is to provide the application of the asymmetric tetramethylguronidin-maleitrile-aminosalicylic acid molecule in the detection of acidic environments.

[0017] Specifically, the molecular probe was prepared by adding 80 times the amount of ClO to a DMF-water solution. - Subsequently, the binary system exhibited strong blue fluorescence emission; with the addition of different concentrations of HCl to the binary system, its fluorescence emission near 470 nm gradually decreased and eventually quenched, indicating that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule reacts with ClO₂. - The resulting binary system exhibits blue fluorescence emission "on-off" detection performance in acidic environments.

[0018] A fourth objective of this invention is to provide the asymmetric tetramethylgurodin-maleitrile-aminosalicylic acid molecule in SCN. - and SiO3 2- Applications of detection.

[0019] Specifically, the molecular probe was prepared by adding 50 times the amount of ClO to a DMF-water solution. - Subsequently, its binary system exhibits weak fluorescence emission; SCN - After the addition of this binary system, its fluorescence emission near 665 nm was enhanced by 23 times; SiO3 2- After being added to this binary system, its fluorescence emission near 663 nm was enhanced by 21 times, indicating that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule reacts with ClO - The resulting binary system for SCN - SiO3 2- It has different red fluorescence emission "off-on" detection performance.

[0020] Compared with the prior art, the present invention has the following technical effects: the tetramethyljulodin-maleitrile-aminosalicylic acid molecular probe, in a DMF-water mixed solution, reacts with ClO... -With increasing concentration, the strong fluorescence emission of this molecular probe near 655 nm under 550 nm excitation gradually weakens, while under 400 nm excitation, the fluorescence emission of this molecular probe near 470 nm gradually strengthens. Under ultraviolet light, with the increase of ClO - As the concentration increases, the red light in the solution gradually decreases while the blue light gradually increases, endowing this single-molecule probe with sensitivity to ClO₂. - The concentration change exhibits a dual-mode dynamic monitoring response with dual excitation-dual emission fluorescence and intuitive red-blue light colorimetric conversion; with increasing alkalinity, the molecular probe's 655 nm fluorescence emission displays an "on-off" dynamic response of first red-shifting and then blue-shifting, and an intuitive dual-mode detection response of gradually dimming red fluorescence emission; furthermore, this molecular probe reacts with low concentrations of ClO - The resulting binary system for SCN - SiO3 2- It exhibits different red fluorescence "off-on" detection responses, and its interaction with high concentrations of ClO - The resulting binary system exhibits a distinct blue fluorescence "on-off" detection response in acidic environments; the detection signal is rapid and intuitive, enabling in-situ, real-time, and field detection of various targets, thus possessing high application value. The preparation process of the tetramethyljulonidine-maleonitrile-aminosalicylic acid molecular probe provided by this invention has advantages such as high yield and mild synthesis conditions, making it suitable for industrial implementation and creating favorable conditions for the widespread application of this tetramethyljulonidine-maleonitrile-aminosalicylic acid molecular probe. Attached Figure Description

[0021] Figure 1 This is the mass spectrum of the asymmetric tetramethyljulonidine-maleitrile-aminosalicylic acid molecule.

[0022] Figure 2 Under 550 nm excitation, tetramethyljulonidine-maleitrile-aminosalicylic acid molecules react with different concentrations of ClO in a 50% DMF aqueous solution. - Fluorescence detection response.

[0023] Figure 3 Under 400 nm excitation, tetramethyljulonidine-maleitrile-aminosalicylic acid molecules were subjected to different concentrations of ClO2 in a 50% DMF-water solution. - Fluorescence detection response.

[0024] Figure 4 Different concentrations of ClO were added to a 50% DMF aqueous solution containing tetramethyljulonidine-maleitrile-aminosalicylic acid. - Photographs taken under ultraviolet light.

[0025] Figure 5The fluorescence response of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule was detected by adding different concentrations of NaOH to a 50% DMF-water solution.

[0026] Figure 6 Photographs of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule under UV light after adding different concentrations of NaOH to a 50% DMF-water solution.

[0027] Figure 7 The fluorescence response of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule was detected by adding different concentrations of HCl to a 50% DMF-water solution.

[0028] Figure 8 To add 20 times the amount of ClO to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule under 550 nm excitation - The response to different acidic environments.

[0029] Figure 9 Adding 20 times the amount of ClO to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule under 400 nm excitation - The response to different acidic environments.

[0030] Figure 10 Adding 80 times the amount of ClO to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule under 550 nm excitation - The response to different acidic environments.

[0031] Figure 11 Adding 80 times the amount of ClO to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule under 400 nm excitation - The response to different acidic environments.

[0032] Figure 12 Add 80 times the amount of ClO to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule - Photos taken under UV light to show the response to different acidic environments.

[0033] Figure 13 The selective fluorescence response of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule was obtained by adding 20 times the amount of other anions under 550 nm excitation.

[0034] Figure 14 The selective fluorescence response of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule was 80 times that of other anions when excited at 400 nm.

[0035] Figure 15 ClO in the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule - It competes with other anions for fluorescence response performance.

[0036] Figure 16 ClO in the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule - Photographs taken under UV light, showing competition with other anions.

[0037] Figure 17 Under 550 nm excitation, tetramethyljulonidine-maleitrile-aminosalicylic acid molecules react with different concentrations of ClO in 50% drinking water-DMF solution. - Fluorescence detection response.

[0038] Figure 18 Under 400 nm excitation, tetramethyljulonidine-maleitrile-aminosalicylic acid molecules react with different concentrations of ClO in 50% drinking water-DMF solution. - Fluorescence detection response. Detailed Implementation

[0039] The molecular probe disclosed in this invention, which has a dual excitation-dual emission-dual mode dynamic monitoring function, has the following molecular structure: .

[0040] It can be prepared by a two-step polymerization reaction using 4-diethylaminosalicylic acid aldehyde, diaminomaleonitrile, and 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine as reactants. The synthetic reaction formula is as follows: .

[0041] Example 1 S1. Place 1 mmol of 4-diethylaminosalicylic aldehyde into a round-bottom flask containing 15 mL of anhydrous ethanol, add 1 mmol of diaminomaleitrile and 100 μL of glacial acetic acid in sequence, and heat to reflux for 4 hours; filter the mixture obtained from the reaction, wash with anhydrous ethanol, and dry to obtain a flesh-colored monoaminomaleitrile-diethylaminosalicylic compound. S2. 1 mmol of monoaminomaleitrile-diethylaminosalicylic acid compound was placed in 30 mL of N,N-dimethylformamide-ethanol mixed solvent with a volume ratio of 1:4. 1 mmol of 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine and 100 μL of concentrated sulfuric acid were added, and the mixture was heated to reflux for 6 hours. The resulting mixture was filtered, washed with anhydrous ethanol, and dried to give dark purple compound A, 403.5 mg, with a yield of 75%.

[0042] Example 2 S1. Place 1 mmol of 4-diethylaminosalicylic aldehyde into a round-bottom flask containing 15 mL of anhydrous ethanol, add 1 mmol of diaminomaleitrile and 100 μL of glacial acetic acid in sequence, and heat to reflux for 4 hours; filter the mixture obtained from the reaction, wash with anhydrous ethanol, and dry to obtain a flesh-colored monoaminomaleitrile-diethylaminosalicylic compound. S2. 1 mmol of monoaminomaleitrile-diethylaminosalicylic acid compound was placed in 30 mL of N,N-dimethylformamide-ethanol mixed solvent with a volume ratio of 1:4. 1 mmol of 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine and 100 μL of concentrated sulfuric acid were added, and the mixture was heated to reflux for 8 hours. The resulting mixture was filtered, washed with anhydrous ethanol, and dried to give dark purple compound B, 408.8 mg, with a yield of 76%.

[0043] Compounds A and B obtained in Examples 1 and 2, respectively, were analyzed and determined by mass spectrometry. Figure 1 To, see Figure 1 The mass spectrometry data are as follows: MS: ion peak m / z is 538.1 [C 32 H 38 Theoretical calculated value of N6O2 M + [538.3]; Elemental analysis: Measured values: C 71.78, H 7.34, N 16.30 [C 32 H 38 The theoretical values ​​for N6O2 are C 71.35, H 7.11, N 16.60; this indicates that compounds A / B are basically consistent with the theoretical values ​​of the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule. Therefore, the molecular structures of compounds A and B can be confirmed as follows: That is, the asymmetric tetramethyljulonidine-maleitrile-aminosalicylic acid molecule.

[0044] Example 3 Tetramethyljulodin-malenitrile-aminosalicylic acid molecules in 50% DMF-H2O mixed solvent for the reaction of ClO - Detection performance: In a DMF-water solution with a water content of 50%, the concentration is 2×10⁻⁶. -5 Different concentrations of ClO were added to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe at mol / L. - Fluorescence emission tests revealed that the tetramethyljulonidine-maleiconitrile-aminosalicylic acid molecular probe exhibits a maximum fluorescence emission peak near 655 nm; with the addition of ClO - As the concentration gradually increases, at an excitation wavelength of 550 nm, ClO -After increasing the concentration of ClO2 by 50 times, the fluorescence emission of this molecular probe at 655 nm gradually decreased and was even quenched. Further increasing the concentration of ClO2... - When the concentration is increased 100 times, the quenched fluorescence essentially no longer changes; see details below. Figure 2 Under the above conditions, at an excitation wavelength of 400 nm, ClO - When the concentration was increased 50-fold from 0, the weak fluorescence emission of the molecular probe at 655 nm was quenched, while its fluorescence emission at around 470 nm was slightly enhanced; further increases in ClO... - When the concentration is increased 100 times, its fluorescence emission at around 470 nm is significantly enhanced, as detailed in [see figure]. Figure 3 Under 365 nm ultraviolet (UV) lamp irradiation, as ClO - As the concentration gradually increased from 0 to 100 times, the tetramethyljulonidine-maleic anhydride molecular probe solution showed a gradual decrease in red fluorescence and a gradual increase in blue fluorescence. Further increases in ClO₂... - The blue fluorescence weakened at a concentration of 300 times; see the attached table for details. Figure 4 These results indicate that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe can effectively target ClO in a 50% aqueous solution of DMF. - Concentration changes exhibit bimodal fluorescence emission under dual excitation and a dynamic dual-mode detection response that clearly shows the conversion of red light to blue light.

[0045] Example 4 Fluorescence detection function of the tetramethyljulodin-maleitrile-aminosalicylic acid molecular probe in different alkaline environments: In a 50% DMF-water solution, at a concentration of 2×10⁻⁶... -5 The fluorescence emission spectra of the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe (mol / L) in the presence of different concentrations of NaOH are as follows: As the NaOH concentration increased from 0 to 30 molar equivalents, the maximum fluorescence emission of the molecular probe near 655 nm gradually red-shifted to 662 nm, and the fluorescence emission intensity decreased by 15%; when the NaOH concentration was further increased to 150 molar equivalents, its fluorescence emission showed a blue shift to 632 nm, and the fluorescence emission intensity decreased by 65%; for detailed results, see [see attached table]. Figure 5 Under 365 nm ultraviolet (UV) light irradiation, as the concentration of NaOH added increased from 0 to 140 molar amounts, the red fluorescence emission of the tetramethyljulonidine-maleiconitrile-aminosalicylic acid molecular probe solution gradually decreased and eventually quenched. For detailed results, please refer to [link to relevant documentation]. Figure 6 These results indicate that the tetramethyljulonidine-maleic anhydride-aminosalicylic acid molecular probe solution possesses a dual-mode detection potential in response to changes in alkaline environment, exhibiting both dynamic fluorescence emission "on-off" and a visually apparent darkening of red fluorescence.

[0046] Example 5 Optical detection capabilities of tetramethyljulodin-maleitrile-aminosalicylic acid molecular probe solution in different acidic environments: In a 50% DMF-water solution with a concentration of 2×10⁻⁶... -5 The fluorescence emission spectra of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule at mol / L in the presence of HCl at different concentrations are as follows: As the concentration of added HCl increases from 0 to 1000 molar equivalents, the maximum fluorescence emission of this molecular probe near 650 nm remains essentially unchanged. For detailed results, please refer to [link to relevant documentation]. Figure 7 These results indicate that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe solution exhibits certain stability in an acidic environment.

[0047] Example 6 Tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe for ClO under different acidic conditions - Fluorescence response: In a 50% aqueous solution of DMF-, at a concentration of 2 × 10⁻⁶... -5 20 times the amount of ClO was added to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe at a concentration of mol / L. - The fluorescence emission spectra of tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe with different concentrations of HCl are as follows: Under 550 nm excitation, 20 times the amount of ClO₂ was added to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe. - Subsequently, it exhibits a maximum fluorescence emission near 655 nm. As the concentration of HCl added to the binary mixture increases from 0 to 200 times the molar amount, the fluorescence emission spectrum of the binary mixture remains essentially unchanged. See [link to specific results] for details. Figure 8 Similarly, under 400 nm excitation, tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe-ClO - In the (20-fold) mixed system, as the concentration of added HCl increased from 0 to 200 molar amounts, the fluorescence emission spectrum of the mixed binary system remained essentially unchanged. See [link to specific results] for details. Figure 9 In contrast, the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe contains 80 times the amount of ClO₂. - Subsequently, under 550 nm excitation, it exhibits weak fluorescence emission near 655 nm. As the concentration of HCl added to the binary mixture increases from 0 to 20 times the molar amount, the weak fluorescence emission spectrum of the binary mixture remains essentially unchanged. See [link to specific results] for details. Figure 10 However, under 400 nm excitation, the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe was added to ClO - After 80 times, it exhibits strong fluorescence emission near 470 nm; as the concentration of HCl added to the binary mixture increases from 0 to 20 times the molar amount, the strong blue fluorescence emission of the binary mixture is gradually quenched. See [link to specific results] for details. Figure 11 Under 365 nm ultraviolet (UV) light irradiation, as the concentration of added HCl increased from 0 to 20 times the molar amount, the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe-ClO... - The blue fluorescence of the (80x) solution gradually decreased until it was quenched. See the attached image for details. Figure 12 These results indicate that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe is relatively stable in acidic environments in the presence of low concentrations of sodium hypochlorite, and its stability is also stable in high concentrations of ClO₂. - In its presence, it exhibits a fluorescent emission "on-off" detection response in acidic environments, namely tetramethyljulonidine-maleonitrile-aminosalicylic acid molecular probe-ClO - The binary system can be used to detect the potential of different acidic environments in a dual-mode detection, which combines blue fluorescence emission "on-off" and visual colorimetric signal changes.

[0048] Example 7 Selectivity of tetramethyljulonidine-maleic acid-aminosalicylic acid molecular pair for anion fluorescence detection: In a 50% DMF-water solution with a concentration of 2×10⁻⁶... -5 Add 20 times the amount of Cl to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe (mol / L). - ,Br - I - C2O4 2- CO3 2- HCO3 - H2PO4 - HSO4 - SO4 2- NO2 - NO3 - SCN - SiO3 2- Fluorescence emission performance tests revealed that under 550 nm excitation, the molecular probe exhibits a maximum fluorescence emission peak around 655 nm; Cl - ,Br - I - C2O4 2- CO3 2- HCO3 - H2PO4 - HSO4 - SO4 2- NO2 - NO3 - SCN - SiO3 2- After the addition of anions, its fluorescence emission spectrum showed almost no significant change; see the detailed results below. Figure 13This is distinctly different from the decrease in fluorescence emission when 20 times the concentration of NaClO is added. Furthermore, fluorescence emission performance tests of the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe with 80 times the amount of the aforementioned anion showed that, under 400 nm excitation, the molecular probe exhibited a weak fluorescence emission peak around 470 nm; Cl - ,Br - I - C2O4 2- CO3 2- HCO3 - H2PO4 - HSO4 - SO4 2- NO2 - NO3 - SCN - SiO3 2- After the addition of tetramethylguronidin-maleitrile-aminosalicylic acid molecular probe with anion, its weak fluorescence emission remained essentially unchanged, even after the addition of 80 times the amount of ClO to the molecular probe. - Subsequently, its fluorescence emission at the 470 nm position was significantly enhanced; see the detailed results below. Figure 14 These results indicate that, among the anions tested above, regardless of high or low concentration conditions, the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe is effective against ClO₂. - It exhibits good fluorescence selective response.

[0049] Example 8 ClO in tetramethyljulodin-maleitrile-aminosalicylic acid molecular probe - Optical competitiveness with other anions: In a 50% aqueous solution of DMF-, at a concentration of 2 × 10⁻⁶... -5 ClO was simultaneously added to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe at a concentration of mol / L. - Fluorescence emission spectroscopy studies of mixed systems with different anions showed that the addition of 50 times ClO₂ to this molecular probe... - Subsequently, its binary system exhibits weak fluorescence emission; SCN - Adding tetramethyljulonidine-maleitrile-aminosalicylic acid molecule-ClO - After the binary system was implemented, its fluorescence emission near 665 nm was enhanced by 23 times; SiO3 2- Adding tetramethyljulonidine-maleitrile-aminosalicylic acid molecule-ClO - After the binary system was implemented, its fluorescence emission near 663 nm was enhanced by 21 times; Cl - ,Br - I - C2O4 2-CO3 2- HCO3 - H2PO4 - HSO4 - SO4 2- NO2 - NO3 - Plasmon anion addition of tetramethylguronidin-maleitrile-aminosalicylic acid molecule-ClO - After the binary system, the ternary mixed system and the molecular probe with ClO - The fluorescence emission spectra of the binary system are similar; see [link to results] for details. Figure 15 Under 365 nm ultraviolet (UV) light irradiation, tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe-ClO - The (50x) mixed system solution exhibits a blue glow. The addition of other anions results in minimal change in the blue glow of the binary system, while SCN... - SiO3 2- After addition, the solution emitted a red glow; see [link to details] for specific results. Figure 16 These indicate that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecule not only affects ClO - It exhibits good selective detection performance, and it is similar to ClO - The resulting binary system for SCN - SiO3 2- It has different red fluorescence emission "off-on" detection performance.

[0050] Example 9 Performance of tetramethyljulonidine-maleitrile-aminosalicylic acid molecule on sodium hypochlorite in a 50% DMF-tap water mixed solvent: In a 50% tap water DMF-water aqueous solution, at a concentration of 2×10⁻⁶... -5 Different concentrations of ClO were added to the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe at a concentration of mol / L. - Fluorescence emission tests revealed that the tetramethyljulonidine-maleiconitrile-aminosalicylic acid molecular probe exhibits a maximum fluorescence emission peak at 655 nm; with the addition of ClO - As the concentration gradually increases, at an excitation wavelength of 550 nm, ClO - After increasing the concentration of ClO2 by 50 times, the fluorescence emission of this molecular probe at 655 nm gradually decreased and was even quenched. Further increasing the concentration of ClO2... - When the concentration is increased 200 times, the quenched fluorescence essentially no longer changes; see details below. Figure 17 Correspondingly, at an excitation wavelength of 400 nm, ClO -When the concentration was increased 50-fold from 0, the weak fluorescence emission of the molecular probe at 655 nm was quenched, while its fluorescence emission at around 470 nm was slightly enhanced; further increases in ClO... - When the concentration is increased 200 times, its fluorescence emission at around 470 nm is significantly enhanced, as detailed in [reference needed]. Figure 18 These results indicate that the tetramethyljulonidine-maleitrile-aminosalicylic acid molecular probe is effective against ClO in tap water. - The concentration change exhibits a dynamic detection response, with red fluorescence converting to blue fluorescence.

Claims

1. A molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function, wherein the molecular probe is an asymmetric tetramethyljulonidine-maleitrile-aminosalicylic acid molecule, and its structure is as follows: 。 2. A method for preparing a molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function as described in claim 1, characterized in that: Includes the following steps: S1. Place 4-diethylaminosalicylic aldehyde into a round-bottom flask containing anhydrous ethanol, add diaminomaleitrile and glacial acetic acid in sequence, and heat to reflux for 4 hours; filter the mixture obtained from the reaction, wash with anhydrous ethanol, and dry to obtain a flesh-colored monoaminomaleitrile-diethylaminosalicylic compound. S2. The monoaminomaleitrile-diethylaminosalicylic acid compound obtained in step S1 is placed in a mixed solution of N,N-dimethylformamide and anhydrous ethanol. 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine and concentrated sulfuric acid are added, and the mixture is heated to reflux for 6-8 hours. The resulting mixture is filtered, washed with anhydrous ethanol, and dried to obtain a dark purple tetramethyljulonidine-maleitrile-aminosalicylic acid molecule.

3. The method for preparing the molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function according to claim 2, characterized in that: In step S2, the molar ratio of the monoaminomaleitrile-diethylaminosalicylic acid compound and 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine is 1:1, the volume ratio of N,N-dimethylformamide and anhydrous ethanol in the mixed solvent is 1:4, and the amount of mixed solvent added is limited to 30 mL of mixed solvent for every 1 mmol of monoaminomaleitrile-diethylaminosalicylic acid compound, and the amount of concentrated sulfuric acid added is 100 μL of concentrated sulfuric acid for every 1 mmol of 1,1,7,7-tetramethyl-8-hydroxy-9-formyljulonidine.

4. A molecular probe with dual excitation-dual emission-dual mode dynamic monitoring function as described in claim 1 in ClO - Applications in detection, wherein the applications do not involve the diagnosis and treatment of diseases, are characterized by: In DMF-aqueous solution, with ClO - With increasing concentration, the fluorescence emission of this molecular probe gradually decreased to quenched at around 655 nm under excitation at 550 nm, while it gradually increased at around 470 nm under excitation at 400 nm; under 365 nm ultraviolet (UV) lamp irradiation, with increasing ClO - With increasing concentration, the molecular probe solution gradually exhibits a decrease in red fluorescence and a gradual increase in blue fluorescence, thus endowing the molecular probe with activity against ClO₂. - The concentration change exhibits a dual-mode dynamic detection response, consisting of dual excitation-dual emission fluorescence and a visually intuitive red-to-blue light colorimetric change in the solution.

5. The application of a molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function as described in claim 1 in alkaline environment detection, wherein the application does not involve the diagnosis and treatment of diseases, characterized in that: In a 50% aqueous solution of DMF, as the NaOH concentration increases, the maximum fluorescence emission of the molecular probe at around 655 nm first red-shifts to 662 nm and then blue-shifts to 632 nm, accompanied by a decrease in fluorescence emission intensity to quenching. Under 365 nm ultraviolet (UV) light irradiation, the red fluorescence of the molecular probe solution gradually disappears, giving the molecular probe a dynamic "on-off" fluorescence emission response to changes in alkaline environment and a dual-mode detection response to visual color changes under UV light.

6. The application of a molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function as described in claim 1 in the detection of acidic environments, wherein the application does not involve the diagnosis and treatment of diseases, characterized in that: In a 50% DMF aqueous solution, the molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function was mixed with 80 times the amount of ClO. - The resulting binary system exhibits dual detection capabilities: blue fluorescence emission "on-off" in acidic environments and visual colorimetric changes under ultraviolet light.

7. A molecular probe with dual excitation-dual emission-dual mode dynamic monitoring function as described in claim 1 in SCN - and SiO3 2- The application of the detection, which does not involve the diagnosis and treatment of diseases, is characterized by: In a 50% DMF aqueous solution, the molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function was mixed with 50 times the amount of ClO₂. - The constructed binary system is used for fluorescence "off-on" detection and identification of SCN. - ; Alternatively, in a 50% DMF aqueous solution, the molecular probe with dual excitation-dual emission-dual-mode dynamic monitoring function is mixed with 50 times the amount of ClO₂. - The constructed binary system is used for fluorescence "off-on" detection and identification of SiO3. 2- .

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