A formaldehyde detection reagent and method

Abstract

A formaldehyde detection reagent, by mass fraction, includes a probe, wherein the probe reagent comprises a deionized aqueous solvent, a small molecule formaldehyde fluorescent probe NBHN, and a fluorescent responsive agent polyacrylic acid. The preparation of the formaldehyde detection reagent specifically includes the following steps: S1: Adding the hydrophilic polymer polyacrylic acid to the deionized aqueous solvent and stirring to dissolve, obtaining a polyacrylic acid solution with a concentration of 1-2 mM / L; S2: Adding the small molecule formaldehyde probe NBHN to the solvent dimethyl sulfoxide, obtaining an NBHN probe solution with a concentration of 0.4-0.6 mg / mL; S3: Mixing the NBHN probe solution from step S2 with a molar ratio of 1:0-5 and the polyacrylic acid solution obtained in step S1, diluting, and then sonicating until dissolved, the reaction system being a pale yellow liquid. The polyacrylic acid fluorescent probe PAA@NBHN of the present invention has a simple synthesis method, mild synthesis conditions, and selectively and rapidly reacts specifically with formaldehyde, enabling real-time and accurate formaldehyde measurement in aqueous solution, exhibiting high selectivity and sensitivity for formaldehyde.

Description

Technical Field

[0001] This invention belongs to the field of air formaldehyde content determination technology, specifically relating to a formaldehyde detection reagent and method. Background Technology

[0002] Formaldehyde (FA) is a colorless gas with a pungent, irritating odor. It is one of the most concerning VOCs (volatile organic compounds) in recent years and also an important basic organic chemical raw material. It is widely used in industrial production, commodity manufacturing, and medical sample processing, playing a role in promoting economic development, improving living standards, and advancing medical research. However, it has wide sources and poses significant health risks, potentially leading to death. The World Health Organization has classified formaldehyde as a Group 1 carcinogen. Inhalation and direct skin contact with formaldehyde can cause respiratory and skin inflammation, allergies, and suppress cellular and humoral immunity. It can even lead to degeneration and necrosis of the nervous system and a reduction in DNA and RNA synthesis, potentially resulting in hepatitis and cancer. Long-term exposure to formaldehyde may also cause memory and intellectual impairment, liver cell damage, and abnormal liver function.

[0003] Environmental pollution has become one of the major global challenges. To achieve accurate environmental monitoring and assessment, efficient and sensitive environmental monitoring methods need to be developed. Currently, instrumental analysis methods such as colorimetry, high-performance liquid chromatography (HPLC), gas chromatography (GC), and mass spectrometry (MS) are mainly used both domestically and internationally. However, these methods have obvious shortcomings. They can cause irreparable damage to chemical and biological samples, and they typically suffer from low sensitivity, complex operation, and high cost, making them unsuitable for detecting formaldehyde levels in the air. Fluorescent probes have attracted considerable attention due to their advantages of simple and convenient operation, high sensitivity, good selectivity, and real-time detection. Currently reported formaldehyde fluorescent probes are designed and prepared without regard to cost; from a synthesis perspective alone, the reaction steps range from five or six to more than ten, and the specific synthesis steps may involve expensive reagents, harsh reaction conditions, and complex post-processing and purification procedures. Such a "consumption-oriented" approach is clearly unsuitable for the requirements of fluorescent probes in the environmental monitoring field. Environmental monitoring places greater emphasis on "cost-effectiveness," demanding high sensitivity, good selectivity, strong stability, rapid response, and simple probe synthesis and preparation.

[0004] In the biomedical field, single-compound fluorescent probes offer advantages, enabling highly selective and sensitive detection of specific biomolecules or biological processes. These single-compound probe designs typically focus on the specific recognition of a single target and the generation of a sensitive signal. However, in environmental monitoring, fluorescent probes can be designed using multi-component systems, similar to the approach used in developing polymer alloys. Such multi-component fluorescent probe systems can include various compounds, such as molecular fluorescent probes and polymeric components. By adjusting the component ratios and interactions, highly selective and sensitive detection of different target pollutants can be achieved. Furthermore, multi-component fluorescent probe designs can meet practical needs in environmental monitoring, such as cost-effectiveness and ease of operation. By rationally designing component ratios and selecting economical and practical compounds, cost-effective fluorescent probes can be developed, reducing detection costs and promoting their practical application.

[0005] Therefore, it is of great significance to develop a new reagent that enables the on-site, rapid and efficient determination of formaldehyde. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide a novel formaldehyde detection reagent and method, which incorporates polyacrylic acid (PAA) into the probe system to achieve on-site, rapid and effective determination of formaldehyde in the air.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A formaldehyde detection reagent, characterized by comprising a probe, wherein the probe reagent comprises 200-300 parts of deionized water solvent, 1-2 parts of small molecule formaldehyde fluorescent probe NBHN, and 7000-8000 parts of fluorescent responsive polyacrylic acid.

[0008] The structural formula of the small molecule formaldehyde fluorescent probe is:

[0009] The small molecule formaldehyde fluorescent probe NBHN is prepared by the following reaction: .

[0010] A method for preparing a formaldehyde detection reagent, by means of a polyacrylic acid component modulating a small molecule formaldehyde fluorescent probe NBHN, includes the following steps: Step S1: Add 0.04-0.06 g of hydrophilic polymer polyacrylic acid to deionized water solvent and stir to dissolve, to obtain a polyacrylic acid solution with a concentration of 1-2 mM / L; Step S2: Add 4-6 mg of the small molecule formaldehyde probe NBHN to 10 mL of the solvent dimethyl sulfoxide to obtain an NBHN probe solution with a concentration of 0.4-0.6 mg / mL; Step S3: Mix the small molecule formaldehyde probe NBHN solution from step S2 with a molar ratio of 1:0~5 and the polyacrylic acid solution obtained in step S1. After dilution, sonicate until dissolved. At this point, the reaction system is a pale yellow liquid.

[0011] In step S2, the preparation method of the small molecule formaldehyde probe NBHN is as follows: the compound NBBN, hydrazine hydrate with a concentration of 80% and anhydrous ethanol are mixed, stirred and heated to 80-85℃, refluxed for 8-10 hours, cooled to room temperature, filtered, washed, vacuum dried, purified, rotary evaporated, and vacuum dried to obtain the small molecule formaldehyde fluorescent probe, wherein the mass ratio of compound NBBN to hydrazine hydrate is 1:1.1-1.5, and the concentration of NBBN solution is 66 mg / mL-110 mg / mL.

[0012] In step S2, the preparation method of compound NBBN is as follows: 5-6 mg of 4-bromo-1,8-naphthalene anhydride, 0.3-0.4 g of n-butylamine, and 40-50 mL of anhydrous ethanol are mixed and refluxed at 80-85 °C for 8-10 h. After cooling and washing, solid NBBN is obtained, wherein the mass ratio of n-butylamine to 4-bromo-1,8-naphthalene anhydride is 1:12-17, and the concentration of 4-bromo-1,8-naphthalene anhydride is 45 mg / mL-70 mg / mL.

[0013] A method for using a formaldehyde detection reagent includes the following steps: Step 1: Accurately weigh 4–6 mg of the small molecule formaldehyde probe NBHN using a 0.01% analytical balance, and prepare a 1.7 mM / L fluorescent probe stock solution using spectroscopically pure dimethyl sulfoxide; prepare a stock solution with a concentration of 10% using double-distilled water to analyze interfering ions. -1 mol / L; Step 2: Add 2 mL of deionized water solution, 20 μL of small molecule formaldehyde fluorescent probe NBHN stock solution and 20 μL of polyacrylic acid stock solution to a fluorescent cuvette and detect the fluorescence intensity in the range of 470 nm to 580 nm on a fluorescence spectrophotometer.

[0014] When the formaldehyde detection reagent detects formaldehyde, the excitation wavelength is 350nm to 420nm, and the wavelength collection range is 405nm to 700nm.

[0015] Multiple interfering ion analytes were prepared into test solutions with concentrations ranging from 35 to 100 μM / L. 2 mL of the test solution, 20 μL of the small molecule formaldehyde fluorescent probe NBHN stock solution, and 20 μL of polyacrylic acid stock solution were added to a fluorescence cuvette. After incubating the sample solution for 10 min, the fluorescence spectrum was measured on a fluorescence spectrophotometer. 395 nm light radiation was used as the excitation light, and the emission spectrum between 415 and 800 nm was recorded. The slit widths for both excitation and emission light were 5.0 nm and 5.0 nm, respectively. The various interfering ion analytes mentioned are Na + Mg 2+ Al 3+ K + Fe 3+ SO4 2- Cl - Co 2+ NO3 2- A stock solution containing Br, glucose, acetaldehyde, glyoxal, acetone aldehyde, sodium pyruvate, salicylaldehyde, p-nitrobenzaldehyde, H2O2, toluene, oxidized glutathione, and reduced glutathione, with a stock solution concentration of 10. -1 mol / L.

[0016] 2 mL of solutions with different pH values, 20 μL of small molecule formaldehyde fluorescent probe NBHN stock solution, and 20 μL of polyacrylic acid stock solution were added to a fluorescent cuvette. The stability at different pH values ​​and the changes in formaldehyde solution were tested on a fluorescence spectrometer.

[0017] The beneficial effects of this invention are: experimental verification shows that the relevant ions do not interfere with the determination of FA by the system. The probe of this invention can be used for the detection of FA. Compared with the prior art, this invention, as a fluorescent probe for selective detection of FA, has the following advantages: 1) The synthesis method of the fluorescent probe of this invention is simple and rapid; 2) The detection method is simple, requiring only ultraviolet and fluorescence spectrometers; 3) The probe has high sensitivity, good selectivity, and fast response speed for FA. Attached Figure Description

[0018] Figure 1 The image shows the hydrogen nuclear magnetic resonance spectrum of the small molecule formaldehyde probe NBHN in deuterated dimethyl sulfoxide according to the present invention.

[0019] Figure 2 The Fourier transform infrared image of the probe NBHN and its intermediate in Embodiment 7 of the present invention.

[0020] Figure 3 This is a graph showing the response of the fluorescent probe PAA@NBHN from Example 8 of this invention to formaldehyde in an aqueous solution (17.7 mM, pH=5.8); where, Figure 3 (a) is a fluorescence spectrum. Figure 3 (b) shows the ultraviolet performance.

[0021] Figure 4 The images show the TEM image and particle size distribution of PAA@NBHN in Example 8 of this invention.

[0022] Figure 5 This is a graph showing the relationship between the fluorescence intensity of the polymer self-assembled fluorescent probes PAA@NBHN and NBHN with formaldehyde at 545 nm and time in Example 9 of the present invention.

[0023] Figure 6 This is a comparison chart of fluorescence intensity when different amounts of polyacrylic acid components are added to the probe in Example 10 of the present invention.

[0024] Figure 7(a) is a fluorescence spectrum of the fluorescent reagent PAA@NBHN in Example 11 of the present invention, showing the fluorescence intensity as a function of formaldehyde concentration.

[0025] Figure 7(b) is a linear relationship between the fluorescence intensity of the fluorescent reagent PAA@NBHN and the formaldehyde concentration in Example 11 of the present invention.

[0026] Figure 8 The fluorescence changes of the fluorescent reagent PAA@NBHN in Example 12 of this invention at different pH values ​​are shown.

[0027] Figure 9 This is a diagram showing the selectivity and anti-interference ability of the fluorescent probe for formaldehyde in Example 13 of the present invention. Implementation

[0028] The specific embodiments of the present invention will be described in detail below.

[0029] A formaldehyde detection reagent, by mass fraction, includes a probe, wherein the probe reagent comprises 200-300 parts of deionized water solvent, 1-2 parts of small molecule formaldehyde fluorescent probe NBHN, and 7000-8000 parts of fluorescent responsive polyacrylic acid.

[0030] The structural formula of the small molecule formaldehyde fluorescent probe NBHN is:

[0031] The small molecule formaldehyde fluorescent probe NBHN is prepared by the following reaction: . Example

[0032] A formaldehyde detection reagent, by mass fraction, includes a probe, wherein the probe reagent comprises 200 parts of deionized water solvent, 1 part of small molecule formaldehyde fluorescent probe, and 7000 parts of fluorescent responsive polyacrylic acid. Example

[0033] A formaldehyde detection reagent, by weight, includes a probe, wherein the probe reagent comprises 250 parts of deionized water solvent, 1.5 parts of small molecule formaldehyde fluorescent probe, and 7500 parts of fluorescent responsive polyacrylic acid. Example

[0034] A formaldehyde detection reagent, by mass fraction, includes a probe, wherein the probe reagent comprises 300 parts of deionized water solvent, 2 parts of small molecule formaldehyde fluorescent probe, and 8000 parts of fluorescent responsive polyacrylic acid. Example

[0035] A method for preparing a formaldehyde detection reagent, which modulates a formaldehyde fluorescent probe using a polyacrylic acid component, includes the following steps: Step S1: Add the hydrophilic polymer polyacrylic acid to an aqueous solvent and stir to dissolve, to obtain a polyacrylic acid solution with a concentration of 1-2 mM / L; Step S2: Add the small molecule formaldehyde probe NBHN to dimethyl sulfoxide to obtain an NBHN probe solution with a concentration of 0.4–0.6 mg / mL; In step S2, the preparation method of the NBHN fluorescent probe is as follows: the compound NBBN, hydrazine hydrate with a concentration of 80% and anhydrous ethanol are mixed, stirred and heated to 80°C, refluxed for 8 hours, cooled to room temperature, filtered, washed, vacuum dried, purified, rotary evaporated, and vacuum dried to obtain a small molecule formaldehyde fluorescent probe, wherein the mass ratio of NBBN solution to hydrazine hydrate is 1:1.1, and the concentration of NBBN is 66 mg / mL.

[0036] In step S2, the preparation method of the compound NBBN is as follows: 4-bromo-1,8-naphthalene anhydride, n-butylamine and anhydrous ethanol are mixed and refluxed at 80°C for 8 hours, cooled and washed to obtain solid NBBN, wherein the mass ratio of n-butylamine and 4-bromo-1,8-naphthalene anhydride is 1:12 and the concentration of 4-bromo-1,8-naphthalene anhydride is 45 mg / mL; In step S3, the NBHN probe solution from step S2 and the polyacrylic acid solution obtained in step S1 (molar ratio of 1:0~5) are mixed, diluted, and then sonicated until dissolved. At this point, the reaction system is a pale yellow liquid. Example

[0037] A method for preparing a formaldehyde detection reagent, which modulates a formaldehyde fluorescent probe using a polyacrylic acid component, includes the following steps: Step S1: Add the hydrophilic polymer polyacrylic acid to an aqueous solvent and stir to dissolve, to obtain a polyacrylic acid solution with a concentration of 1-2 mM / L; Step S2: Add the small molecule formaldehyde probe NBHN to dimethyl sulfoxide to obtain an NBHN solution with a concentration of 0.5 mg / mL; In step S2, the preparation method of the small molecule formaldehyde probe NBHN is as follows: compound NBBN, 80% hydrazine hydrate and anhydrous ethanol are mixed, stirred and heated to 83°C, refluxed for 9 hours, cooled to room temperature, filtered, washed, vacuum dried, purified, rotary evaporated, and vacuum dried to obtain the small molecule formaldehyde fluorescent probe, wherein the mass ratio of NBBN solution to hydrazine hydrate is 1:1.3, and the concentration of NBBN is 66 mg / mL to 110 mg / mL.

[0038] In step S2, the compound NBBN is prepared by mixing 4-bromo-1,8-naphthalene anhydride, n-butylamine and anhydrous ethanol, refluxing at 83°C for 9 hours, cooling, washing, and obtaining solid NBBN, wherein the mass ratio of n-butylamine to 4-bromo-1,8-naphthalene anhydride is 1:14, and the concentration of 4-bromo-1,8-naphthalene anhydride is 63 mg / mL; Step S3: Mix the NBHN probe solution from step S2 (molar ratio 1:3) with the polyacrylic acid solution obtained in step S1, dilute the mixture, and sonicate until dissolved. At this point, the reaction system is a pale yellow liquid. Example

[0039] A method for preparing a formaldehyde detection reagent, which modulates a formaldehyde fluorescent probe using a polyacrylic acid component, includes the following steps: Step S1: Add the hydrophilic polymer polyacrylic acid to an aqueous solvent and stir to dissolve, to obtain a polyacrylic acid solution with a concentration of 1-2 mM / L; Step S2: Add the small molecule formaldehyde probe NBHN to dimethyl sulfoxide to obtain an NBHN solution with a concentration of 0.6 mg / mL; In step S2, the preparation method of the small molecule formaldehyde probe NBHN is as follows: the compound NBBN, 80% hydrazine hydrate and anhydrous ethanol are mixed, stirred and heated to 85°C, refluxed for 10 h, cooled to room temperature, filtered, washed, vacuum dried, purified, rotary evaporated and vacuum dried to obtain the small molecule formaldehyde fluorescent probe, wherein the mass ratio of NBBN solution to hydrazine hydrate is 1:1.5, and the concentration of NBBN is 66 mg / mL to 110 mg / mL.

[0040] In step S2, the compound NBBN is prepared by mixing 4-bromo-1,8-naphthalene anhydride, n-butylamine and anhydrous ethanol, refluxing at 85°C for 10 h, cooling, washing, and obtaining solid NBBN, wherein the mass ratio of n-butylamine to 4-bromo-1,8-naphthalene anhydride is 1:17, and the concentration of 4-bromo-1,8-naphthalene anhydride is 70 mg / mL; In step S3, the NBHN probe solution from step S2 with a molar ratio of 1:5 and the polyacrylic acid solution obtained in step S1 are mixed, diluted, and then sonicated until dissolved. At this point, the reaction system is a pale yellow liquid. Example

[0041] like Figure 1 As shown, the small molecule formaldehyde fluorescent probe NBHN has been characterized by 1H NMR spectroscopy.

[0042] This invention screens a rapid formaldehyde detection method using polyacrylic acid as a component, comprising the following steps: Synthesis of small molecule formaldehyde fluorescent probe NBHN: Synthesis of intermediate NBBN: 0.18 g n-butylamine, 2.77 g 4-bromo-1,8-naphthalene anhydride (1:15) and 50 mL anhydrous ethanol were added to round-bottom flasks respectively. Under nitrogen protection, the mixture was stirred and heated to reflux at 85 °C for 9 h. After the reaction was completed, the reaction solution was cooled to room temperature, and a solid precipitated. The solid was filtered, washed three times with ice-cold ethanol, and dried under vacuum overnight to obtain a grayish-white solid NBBN. Then, 1.66 g of NBBN, 2.16 g of 80% hydrazine hydrate (1:1.3), and 20 mL of ethanol were placed in a round-bottom flask and heated to reflux with stirring at 85 °C. After reacting for 9 h, the mixture was cooled to room temperature, and an orange solid slowly precipitated. The precipitate was filtered, washed three times with cold ethanol, and dried under vacuum overnight. Purification was then performed using column chromatography with an eluent (dichloromethane:methanol mixture = 30:1), followed by rotary evaporation and vacuum drying to obtain a yellow solid, NBHN. Figure 1 As shown, the structure of the product has been characterized by 1H NMR spectroscopy, as follows: Figure 2 As shown, the compound NBBN and the small molecule formaldehyde probe NBHN have been characterized by Fourier transform infrared spectroscopy.

[0043] 1) Add the small molecule formaldehyde fluorescent probe NBHN to dimethyl sulfoxide to obtain an NBHN solution with a concentration of 0.4–0.6 mg / mL; 2) Weigh a certain amount of the hydrophilic polyacrylic acid polymer and dissolve it in an aqueous solvent. Stir thoroughly to dissolve the polymer and obtain a solution with a concentration of 1-2 mM / L. 3) The NBHN solution and the polymer solution with a molar ratio of 1:0 to 5 were ultrasonically mixed to obtain the mixed fluorescent reagent PAA@NBHN, and then diluted with ultrapure water to obtain a probe solution with a final concentration of 17.7 μM (calculated based on the concentration of the small molecule formaldehyde probe NBHN).

[0044] This invention also provides an application of a supramolecular self-assembled fluorescent probe in the detection of formaldehyde.

[0045] Furthermore, when the supramolecular self-assembled fluorescent probe detects formaldehyde, the excitation wavelength is 350 nm to 420 nm, and the wavelength collection range is 405 nm to 700 nm. Example

[0046] Investigating the UV-Vis spectrum and fluorescence response of the fluorescent probe PAA@NBHN UV-Vis and fluorescence performance experiments were conducted in an aqueous solution (17.7 mM, pH = 5.8). Figure 3 (a) A weak fluorescence emission peak is shown at 545 nm. Figure 3 (b) The free probe shows a UV-Vis absorption peak at 470 nm. When the PAA@NBHN probe reacts with FA, the UV-Vis absorption peak is enhanced, the fluorescence intensity at 545 nm is increased by 16 times, and the solution color changes from colorless to yellow.

[0047] like Figure 4 As shown, the polymer self-assembled fluorescent probe PAA@NBHN prepared in this embodiment is a spherical nanoparticle with a particle size of approximately 60 nm. Example

[0048] Investigating the response time of the fluorescent probe PAA@NBHN to formaldehyde. Take 2 mL of the fluorescent probe solution prepared in Example 1, add formaldehyde solution (final concentration 35 μM), and perform kinetic detection (λex = 395 nm). Detect once every 1 min for 10 min.

[0049] Transfer 2 mL of ultrapure water, add 20 μL of small molecule fluorescent probe NBHN (concentration of 0.5 mg / mL), add formaldehyde solution (final concentration of 35 μM), and perform fluorescence kinetic detection (λex = 395 nm). Detect once every 1 min for 60 min.

[0050] The kinetic response of the mixed fluorescent probe PAA@NBHN and compound 1 to formaldehyde is as follows: Figure 5 As shown, the fluorescence intensity of compound 1 increases with increasing reaction time with formaldehyde, reaching equilibrium at approximately 40 min; while the mixed fluorescent probe PAA@NBHN reaches equilibrium at approximately 10 min, indicating that the addition of polyacrylic acid results in a much faster response to formaldehyde than compound 1. This demonstrates that incorporating polyacrylic acid as a component into the fluorescent probe system has a significant effect on regulating its adaptability in the field of environmental detection. Example

[0051] The response of adjusting the ratio of polymeric components polyacrylic acid (PAA) and compound 1 (NBHN) to formaldehyde Prepare PAA and NBHN molar ratios (0.25:1, 0.5:1, 0.75:1, 1:2, 1:3, 1:4, 1:5). Transfer 2 mL of each of these fluorescent solutions to formaldehyde solution (final concentration 35 μM), react for 10 min, and perform kinetic analysis (λex = 395 nm). Record the fluorescence intensity at 545 nm. Figure 6 As shown, the fluorescence intensity gradually decreased with increasing polyacrylic acid content, while the probe solution (PAA:NBHN=0.75:1) exhibited the strongest fluorescence response at 545 nm. This indicates that the probe solution (PAA@NBHN=0.75:1) has a better detection effect on formaldehyde. Example

[0052] Investigating the response performance of a fluorescent reagent (PAA@NBHN) to different concentrations of formaldehyde. 2 mL of the fluorescent reagent (PAA@NBHN) solution prepared in Example 4 was transferred and added to formaldehyde solutions of different concentrations (0–200 μM) for fluorescence concentration titration experiments (λex = 395 nm). As shown in Figure 7(a), the fluorescence intensity at 545 nm gradually increased with the increase of formaldehyde concentration. In addition, as shown in Figure 7(b), there is a linear relationship between the fluorescence intensity of probe PAA@NBHN and formaldehyde concentration, indicating that probe PAA@NBHN has a good ratio detection effect for formaldehyde. Example

[0053] Investigating the response performance of the fluorescent reagent (PAA@NBHN) to formaldehyde in solutions of different pH values. Prepare PBS buffer solutions with pH values ​​of 5–8. Following the method for preparing the fluorescent probe PAA@NBHN in Example 4, replace deionized water with aqueous solutions of different pH values ​​to prepare PAA@NBHN solutions under different pH conditions. Take 2 mL of each probe solution at different pH values ​​and measure the change in fluorescence intensity before and after reaction with 20 μL of formaldehyde (final concentration: 35 μM). The fluorescence intensity of the probe is relatively stable at different pH values; with the addition of FA (final concentration: 35 μM), such as… Figure 8 As shown, when the pH of the probe solution is in the range of 5–8, the fluorescence change of the formaldehyde-induced fluorescent reagent (PAA@NBHN) is almost unaffected by the solution pH. Instrument parameters: slit widths for excitation and emission wavelengths are 5.0 nm and 5.0 nm, respectively; the maximum excitation wavelength of the fluorescent probe solution is λex at approximately 395 nm, and the maximum fluorescence emission wavelength is λem at approximately 545 nm. Example

[0054] Testing the interference resistance and selectivity of the fluorescent reagent (PAA@NBHN) against formaldehyde. The concentration is 10. -1Stock solutions of interfering analytes at mol / L include NaCl, FeSO4, AlCl3, Co(NO3)2, KBr, Mg(NO3)2, trichloroacetaldehyde, glucose, acetaldehyde, glyoxal, acetone aldehyde, sodium pyruvate, salicylaldehyde, p-nitrobenzaldehyde, H2O2, toluene, oxidized glutathione, and reduced glutathione.

[0055] In the selectivity experiment, the interfering analyte solution (final concentration 1 mM) was transferred to 2 mL of the fluorescent probe PAA@NBHN solution prepared in Example 4, and the fluorescence spectrum was measured after reacting for 10 min. In the interference experiment, the interfering analyte solution (final concentration 1 mM) and 20 μL of formaldehyde were transferred to 2 mL of the fluorescent probe PAA@NBHN solution prepared in Example 6, and the fluorescence spectrum was measured after reacting for 10 min. The excitation wavelength during the fluorescence spectroscopy measurement was 395 nm, and the wavelength collection range was 415–700 nm. Figure 9 As shown, when different interfering solutions were added to the fluorescent probe PAA@NBHN solution, only the formaldehyde solution significantly enhanced the fluorescence intensity of the probe PAA@NBHN, while the other interfering solutions did not cause significant changes in the fluorescence intensity of the probe PAA@NBHN. Furthermore, the presence of the aforementioned common analytes in the solution did not affect the formaldehyde-induced fluorescence change of the probe PAA@NBHN, indicating that the coexistence of formaldehyde with various analytes does not interfere with the formaldehyde-triggered fluorescence response. This demonstrates that the polymeric fluorescent probe has strong specificity for formaldehyde.

[0056] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A formaldehyde detection reagent, characterized by, by mass parts, It includes a probe, wherein the probe reagent comprises 200-300 parts of deionized water solvent, 1-2 parts of small molecule formaldehyde fluorescent probe NBHN, and 7000-8000 parts of fluorescent responsive polyacrylic acid; The structural formula of the small molecule formaldehyde fluorescent probe NBHN is: 。 2. The formaldehyde detection reagent according to claim 1, characterized in that, The small molecule formaldehyde fluorescent probe NBHN is prepared by the following reaction: 。 3. A method for preparing the formaldehyde detection reagent according to claim 1, characterized in that, by mass parts, This was achieved by modulating the small molecule formaldehyde fluorescent probe NBHN using polyacrylic acid components, and included the following steps: Step S1: Add 0.04-0.06 g of hydrophilic polymer polyacrylic acid to deionized water solvent and stir to dissolve, to obtain a polyacrylic acid solution with a concentration of 1-2 mM / L; Step S2: Add 4-6 mg of the small molecule formaldehyde probe NBHN to 10 mL of the solvent dimethyl sulfoxide to obtain an NBHN probe solution with a concentration of 0.4-0.6 mg / mL; Step S3: Mix the small molecule formaldehyde probe NBHN solution from step S2 with a molar ratio of 1:0~5 and the polyacrylic acid solution obtained in step S1. After dilution, sonicate until dissolved. At this point, the reaction system is a pale yellow liquid.

4. The method for preparing a formaldehyde detection reagent according to claim 3, characterized in that, In step S2, the preparation method of the small molecule formaldehyde probe NBHN is as follows: compound NBBN, hydrazine hydrate with a concentration of 80% and anhydrous ethanol are mixed, stirred and heated to 80-85℃, refluxed for 8-10 hours, cooled to room temperature, filtered, washed, vacuum dried, purified, rotary evaporated, and vacuum dried to obtain the small molecule formaldehyde fluorescent probe, wherein the mass ratio of compound NBBN to hydrazine hydrate is 1:1.1-1.5, and the concentration of NBBN solution is 66 mg / mL-110 mg / mL.

5. The method for preparing a formaldehyde detection reagent according to claim 4, characterized in that, In step S2, the preparation method of compound NBBN is as follows: 5-6 mg of 4-bromo-1,8-naphthalene anhydride, 0.3-0.4 g of n-butylamine, and 40-50 mL of anhydrous ethanol are combined and refluxed at 80-85 °C for 8-10 h. After cooling and washing, solid NBBN is obtained, wherein the mass ratio of n-butylamine to 4-bromo-1,8-naphthalene anhydride is 1:12-17, and the concentration of 4-bromo-1,8-naphthalene anhydride is 45 mg / mL-70 mg / mL.

6. A method of using the formaldehyde detection reagent according to claim 1, characterized in that, Includes the following steps: Step 1: Accurately weigh 4-6 mg of the small molecule formaldehyde probe NBHN using an analytical balance of 0.01 g / L, and prepare a 1.7 mM / L fluorescent probe stock solution using spectroscopically pure dimethyl sulfoxide; prepare a stock solution of interfering ion analytes with a concentration of 0.1 M / L using double-distilled water. Step 2: Add 2 mL of deionized water solution, 20 μL of small molecule formaldehyde fluorescent probe NBHN stock solution and 20 μL of polyacrylic acid stock solution to a fluorescent cuvette and detect on a fluorescence spectrophotometer. As the formaldehyde solution is added, the fluorescence intensity in the range of 470 nm to 580 nm gradually increases.

7. The method of using the formaldehyde detection reagent according to claim 6, characterized in that, When the formaldehyde detection reagent detects formaldehyde, the excitation wavelength is 350nm to 420nm, and the wavelength collection range is 405nm to 700nm.

8. The method of using the formaldehyde detection reagent according to claim 6, characterized in that, Multiple interfering ion analytes were prepared into test solutions with concentrations ranging from 35 to 100 μM / L. 2 mL of the test solution, 20 μL of the small molecule formaldehyde fluorescent probe NBHN stock solution, and 20 μL of polyacrylic acid stock solution were added to a fluorescence cuvette. After incubating the sample solution for 10 min, the fluorescence spectrum was measured on a fluorescence spectrophotometer. 395 nm light radiation was used as the excitation light, and the emission spectrum between 415 and 800 nm was recorded. The slit widths for both excitation and emission light were 5.0 nm and 5.0 nm, respectively. The various interfering ion analytes mentioned are Na + Mg 2+ Al 3+ K + Fe 3+ SO4 2- Cl - Co 2+ A stock solution containing NO32-, Br, glucose, acetaldehyde, glyoxal, acetone aldehyde, sodium pyruvate, salicylaldehyde, p-nitrobenzaldehyde, H2O2, toluene, oxidized glutathione, and reduced glutathione, with a stock solution concentration of 10. -1 mol / L.

9. The method of using the formaldehyde detection reagent according to claim 6, characterized in that, 2 mL of solutions with different pH values, 20 μL of small molecule formaldehyde fluorescent probe NBHN stock solution, and 20 μL of polyacrylic acid stock solution were added to a fluorescent cuvette. The stability at different pH values ​​and the change in fluorescence intensity after the addition of formaldehyde solution were tested on a fluorescence spectrometer.

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