A paper-based sensor for specific and rapid detection of ammonia gas
By preparing a paper-based sensor using a fluorescent probe (R)-1, the problem of insensitive ammonia detection in existing technologies is solved, enabling rapid and visualized ammonia detection with high selectivity and low cost.
Patent Information
- Application Number
- CN202310615405.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-29
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2043-05-29
AI Technical Summary
Existing technologies lack highly sensitive and fast ammonia sensors, making it difficult to achieve real-time detection and effective monitoring of ammonia in the environment.
A paper-based sensor was prepared using a fluorescent probe. Rapid detection was achieved by the color change of the fluorescent probe (R)-1 in the presence of ammonia. The fluorescent probe was prepared by reacting compounds such as (R)-4, N,N-diisopropylethylamine, bromomethyl methyl ether, dilute hydrochloric acid, ethyl acetate, n-butyllithium, N,N-dimethylformamide, and sodium bicarbonate.
It achieves low-cost, rapid, and visualized ammonia detection, with high selectivity and sensitivity, and is suitable for the detection of ammonia in the environment.
Smart Images
Figure CN116625945B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of chemical analysis detection, in particular to a paper-based sensor for specifically and rapidly detecting ammonia. BACKGROUND
[0002] Ammonia is a widely used toxic gas, colorless and with irritating odor. Under normal circumstances, the volume concentration of ammonia in the atmosphere is about 1-5*10 -3 ppm, which is mainly derived from agricultural activities, such as livestock breeding, chemical fertilizer and organic soil volatilization. At the same time, industrial activities and resident traffic also produce part of the ammonia.
[0003] When the volume concentration of ammonia in the environment is greater than 0.25 ppm, ammonia has a stimulating and corrosive effect on the upper respiratory tract of the human body. The central nervous system of the human body will also be damaged to a certain extent for a long time in a high-concentration ammonia environment. On the other hand, ammonia increases the mass concentration of atmospheric haze particles by forming ammonium salt, thereby causing great pollution to the environment. Therefore, it is necessary to develop an ammonia sensor with high sensitivity to detect the ammonia concentration in the environment in real time. SUMMARY
[0004] The application aims to provide a paper-based sensor for specifically and rapidly detecting ammonia, a fluorescent probe detection method with short time consumption and low detection limit, and wide application prospect in ammonia detection in the environment.
[0005] According to one object of the application, the application provides a paper-based sensor for specifically and rapidly detecting ammonia, which is prepared by the following method:
[0006] S1, a proper amount of probe (R)-1 is weighed and dissolved in dichloromethane to prepare a probe solution;
[0007] S2, the qualitative filter paper is fully soaked with the probe solution, and the paper-based sensor is obtained after being naturally dried, and then the paper-based sensor is placed in an ammonia environment or immersed in an ammonia aqueous solution, and the color change of the sensor is observed under natural light.
[0008] Further, in S2, the concentration of the prepared probe solution is 16 mM, the initial color of the paper-based sensor is light yellow, and the color changes to reddish brown after reacting with ammonia under natural light.
[0009] Further, the preparation method of the probe (R)-1 comprises the following steps:
[0010] S1, (R)-4 was weighed and dissolved in super dry dichloromethane, N, N-diisopropyl ethylamine was added dropwise, then bromomethyl methyl ether was added dropwise, dilute hydrochloric acid was added to quench the reaction, then ethyl acetate was used for extraction, the organic phase was combined, anhydrous sodium sulfate was used for drying, rotary evaporation was performed to obtain a crude product, column chromatography was used for purification, and vacuum drying was performed to obtain white solid (R)-3;
[0011] S2, (R)-3 was weighed and dissolved in super dry tetrahydrofuran, then n-butyllithium was added dropwise, the reaction was restored to room temperature, then super dry N-N dimethylformamide was gradually added, the reaction was restored to room temperature, then saturated ammonium chloride solution was added under the condition of ice water bath to quench the reaction, then ethyl acetate was used for extraction, the organic phase was combined, anhydrous sodium sulfate was used for drying, rotary evaporation was performed to obtain a crude product, column chromatography was used for purification, and vacuum drying was performed to obtain yellow oil (R)-2.
[0012] S3, (R)-2 was dissolved in a mixed solvent of dichloromethane and anhydrous ethanol, concentrated hydrochloric acid was added dropwise, then sodium bicarbonate was added to quench the reaction, then dichloromethane was used for extraction, the organic phase was combined, anhydrous sodium sulfate was used for drying, and rotary evaporation was performed to obtain fluorescent probe (R)-1.
[0013] Further, in S1, N, N-diisopropyl ethylamine was added under the condition that the temperature was -5-5 ℃, the reaction time after the addition of N, N-diisopropyl ethylamine was 2.5-3.5 h and 0.5-1 h, the eluent volume ratio of petroleum ether: ethyl acetate in column chromatography purification was 40:1, and the molar ratio of (R)-4:N, N-diisopropyl ethylamine: bromomethyl methyl ether was 1:2.2:1.5.
[0014] Further, in S2, n-butyllithium was added under the condition that the temperature was -5-5 ℃, n-butyllithium was added for 1.5-2.5 h, then super dry N-N dimethylformamide was gradually added, super dry N-N dimethylformamide was added for 0.5-1.5 h, then saturated ammonium chloride solution was added under the condition of ice water bath to quench the reaction, and the eluent volume ratio of petroleum ether: ethyl acetate in column chromatography purification was 10:1, and the molar ratio of (R)-3:n-butyllithium:N-N dimethylformamide was 1:3.5:1.5.
[0015] Further, in S3, concentrated hydrochloric acid was added dropwise overnight, then sodium bicarbonate was added to quench the reaction, and the volume ratio of the mixed solvent was dichloromethane: anhydrous ethanol = 1:1.
[0016] Beneficial effects
[0017] The fluorescent probe raw material disclosed by the application has low price and simple preparation. The detection method has short time consumption, low detection limit, good selectivity of a paper-based sensor basically developed by the fluorescent probe, high visualization degree, and is convenient to operate, and has wide application prospect in the field of ammonia detection in the environment. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 Synthetic route of the fluorescent probe (R)-1 of the present application;
[0019] Figure 2 Fluorescence spectrum of the fluorescent probe (R)-1 of the present application and different concentrations of ammonia;
[0020] Figure 3 Curve of the relationship between the fluorescence intensity of the system at 538 nm and the concentration of ammonia;
[0021] Figure 4 Fluorescence spectrum of the fluorescent probe (R)-1 of the present application and 1000 eq of ammonia;
[0022] Figure 5 Fluorescence spectrum of the fluorescent probe (R)-1 of the present application and competitive analyte;
[0023] Figure 6 Color change diagram of the paper-based sensor and ammonia or ammonia water under natural light. DETAILED DESCRIPTION
[0024] The technical solutions of the present application will be described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.
[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0027] Example 1
[0028] like Figure 1 As shown,
[0029] A method for preparing a fluorescent probe includes the following steps:
[0030] S1, weigh (R)-4 (17.5 mmol, 5 g) and dissolve it completely in ultra-dry dichloromethane (DCM) (100 mL). Cool the solution to 0 °C and slowly add N,N-diisopropylethylamine (DIPEA) (38.5 mmol, 6.4 mL). React for 3 h.
[0031] Then, bromomethyl methyl ether (26.2 mmol, 2.1 mL) was slowly added dropwise, and the reaction was allowed to proceed for 1 hour.
[0032] The reaction was quenched by adding 2MHCl (50mL) at 0℃, extracted with 3×20mL ethyl acetate, the organic phases were combined, dried over anhydrous Na2SO4, filtered, and the solvent was removed under reduced pressure.
[0033] The crude product was purified by column chromatography with petroleum ether:ethyl acetate = 40:1 as the eluent to give a white solid (R)-3.
[0034] S2, (R)-3 (6.1 mmol, 2 g) was fully dissolved in ultra-dry THF (50 mL), the solution was cooled to 0 °C, and n-butyllithium (21.4 mmol, 13.4 mL, 1.6 M dissolved in n-hexane) was slowly added dropwise, and the reaction was allowed to return to room temperature for 2 h.
[0035] Cool to 0°C again, slowly add ultra-dry DMF (9.2 mmol, 0.72 mL), and allow to return to room temperature for 1 hour.
[0036] The reaction was quenched by adding 10 mL of saturated NH4CI at 0°C, extracted with 3 x 20 mL of ethyl acetate, the organic phase was combined, dried over anhydrous Na2SO4, filtered, and the solvent was removed under reduced pressure;
[0037] The crude product was purified by column chromatography, with petroleum ether: ethyl acetate = 10:1 as the eluent, to obtain the product (R)-2 as a yellow oil;
[0038] S3, concentrated hydrochloric acid (1 ml, 12M) was added dropwise to a DCM / ethanol solution of (R)-2, and the reaction was allowed to proceed overnight. Solid NaHCO3 was added to the mixture until no gas bubbles were produced;
[0039] The reaction was quenched by adding 10 mL of saturated NH4CI at 0°C, extracted with 3 x 20 mL of ethyl acetate, the organic phase was combined, dried over anhydrous Na2SO4, filtered, and the solvent was removed under reduced pressure;
[0040] The fluorescent probe prepared in this example is simple to prepare and low in cost.
[0041] Example 2
[0042] As shown in Figures 2-6 A method for detecting ammonia gas using a fluorescent probe, comprising the following steps:
[0043] S1, dissolve the probe (R)-1 in an appropriate amount of chromatographic grade dimethyl sulfoxide to prepare a 1.6 mM probe solution, and dilute commercially available ammonia water with ultrapure water to different concentrations, with concentrations of 1.6 mM (1 eq), 80 mM (50 eq), 160 mM (100 eq), 320 mM (200 eq), 480 mM (300 eq), 640 mM (400 eq), 800 mM (500 eq), 960 mM (600 eq), 1120 mM (700 eq), 1280 mM (800 eq), 1440 mM (900 eq), and 1600 mM (1000 eq).
[0044] Add 50 ul of the probe stock solution and 50 ul of ammonia water of different equivalents to a centrifuge tube using a pipette, allow to react for 5 min, then add 3.9 ml of DMSO to make up to 4 mL, and measure the fluorescence. The excitation wavelength and emission wavelength are set to 430 nm and 450-720 nm, respectively, and the final concentration of (R)-1 in the solution is 20 uM;
[0045] S2, the probe (R)-1 itself does not emit a fluorescent signal, but as the concentration of ammonia water increases, the fluorescence at 538 nm is significantly enhanced;
[0046] There is a good linear relationship between the fluorescence intensity and the ammonia concentration in the range of 1-1000 eq; according to the calculation formula LOD=3sigma / k, the detection limit thereof is 4.37uM, indicating that (R)-1 has high sensitivity to ammonia;
[0047] S3, the competitive analyte is dissolved in ultrapure water, first prepared into 1600mM analyte solution, then diluted to different concentrations according to a certain proportion, and the concentration gradient is consistent with the ammonia concentration, which is 1.6mM, 80mM, 160mM, 320mM, 480mM, 640mM, 800mM, 960mM, 1120mM, 1280mM, 1440mM, 1600mM;
[0048] The probe stock solution and the analyte solution are added into the centrifugal tube in sequence by using a pipette, and after 5min of sufficient reaction, 3.9ml of DMSO is added to make the volume to 4ml, and the fluorescence is measured;
[0049] S4, the competitive analyte includes amino alcohol (L-prolinol, L-alaninol, L-valinol, L-leucinol, L-tryptophan alcohol, L-threoninol, L-isoleucinol, L-phenylalaninol, (S)-3-amino-3-phenylpropanol, BOC-L-alaninol, (S)-diphenylprolinol, L-aminopropanol, L-2-aminobutanol, (S)-3-amino-1,2-propanediol), cations (Al 3+ , Na + , K + , Cu 2+ , Fe 3+ , Ni 2+ , Mg 2+ ), and (1S,2S)-1,2-diphenylethylenediamine, SO2, wherein the cation donors are corresponding chloride salt solutions, and the SO2 donor is sodium sulfite;
[0050] S5, only when (R)-1 reacts with ammonia, the fluorescence is significantly enhanced, and when (R)-1 reacts with other analytes, no obvious fluorescence emission is observed, indicating that (R)-1 has high chemical selectivity to ammonia.
[0051] The fluorescent probe of the application can specifically and selectively recognize ammonia, and has high sensitivity, short reaction time and simple operation.
[0052] Example 3
[0053] A paper-based sensor for specifically and rapidly detecting ammonia gas is prepared by the following method:
[0054] S1, an appropriate amount of (R)-1 was weighed and dissolved in DCM to prepare a 16mM probe solution, then the qualitative filter paper was soaked with the probe solution and taken out to dry naturally, the test paper was light yellow;
[0055] Subsequently, the test paper was immersed in each analyte solution for 10s, then taken out, under natural light, the test paper reacted with ammonia and the color changed obviously, from light yellow to red brown, while the other analytes had no substantial color change.
[0056] The paper-based sensor of the application can quickly and visually detect ammonia without the need for complex equipment.
[0057] The fluorescent probe of the application is simple to prepare and low in cost, and has high sensitivity, good selectivity and rapid response for ammonia detection. Based on the fluorescent probe, a paper-based sensor is developed, which changes color from light yellow to red brown under natural light after reacting with ammonia, realizing rapid detection and easy visualization of ammonia, and having important application value in many fields.
[0058] The fluorescent probe of the application is simple to prepare and low in cost, and has high sensitivity, good selectivity and rapid response for ammonia detection.
[0059] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.
Claims
1. A paper-based sensor for the specific and rapid detection of ammonia, characterized in that, It is prepared by the following method: S1, weigh an appropriate amount of probe. Dissolve in dichloromethane to prepare a probe solution; S2. The qualitative filter paper is fully soaked in the probe solution, taken out and air-dried to obtain the paper-based sensor. The paper-based sensor is then placed in an ammonia environment or immersed in an ammonia solution, and the color change of the sensor is observed under natural light.
2. The paper-based sensor for specific and rapid detection of ammonia according to claim 1, characterized in that, In S2, the concentration of the probe solution was 16 mM. The initial color of the paper-based sensor was pale yellow, and after reacting with ammonia, the color turned reddish-brown under natural light.
3. The paper-based sensor for specific and rapid detection of ammonia according to claim 1, characterized in that, The probe Preparation method of fluorescent probe The synthetic route is as follows: ； Includes the following steps: S01, weighing Dissolve completely in ultra-dry dichloromethane, then add N dropwise. Diisopropylethylamine was added dropwise, followed by the addition of bromomethyl methyl ether. The reaction was quenched with dilute hydrochloric acid, and then extracted with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and evaporated by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography and dried under vacuum to obtain a white solid. ; S02, weigh Dissolve the substance completely in ultra-dry tetrahydrofuran, add n-butyllithium dropwise, restore the reaction to room temperature, and then gradually add ultra-dry tetrahydrofuran. Dimethylformamide was reacted at room temperature; the reaction was quenched by adding saturated ammonium chloride solution under ice-water bath conditions, followed by extraction with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and evaporated by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography and dried under vacuum to obtain a yellow oily product. ; S03, Dissolved in a suitable amount of a mixed solvent of dichloromethane and anhydrous ethanol, concentrated hydrochloric acid was added dropwise, the reaction was quenched with sodium bicarbonate, and then extracted with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, and obtained by rotary evaporation. .
4. The paper-based sensor for specific and rapid detection of ammonia according to claim 3, characterized in that, In SO1, N,N-diisopropylethylamine is added at a temperature of -5 to 5°C. The reaction time after diisopropylethylamine was 2.5–3.5 h and 0.5–1 h. The volume ratio of the eluent phase for column chromatography purification was petroleum ether: ethyl acetate = 40:1, and the molar ratio of (R)-4: N,N-diisopropylethylamine: bromomethyl methyl ether was 1:2.2:1.
5.
5. The paper-based sensor for specific and rapid detection of ammonia according to claim 3, characterized in that, In SO2, n-butyllithium is added at a temperature of -5 to 5°C. After 1.5 to 2.5 hours of adding n-butyllithium, ultra-dry N-N dimethylformamide is gradually added. After 0.5–1.5 h of dimethylformamide reaction, the reaction was quenched by adding saturated ammonium chloride solution under ice-water bath conditions; the eluent volume ratio for column chromatography purification was petroleum ether: ethyl acetate = 10:
1. n-Butyllithium: The molar ratio of dimethylformamide is 1:3.5:1.
5.
6. The paper-based sensor for specific and rapid detection of ammonia according to claim 3, characterized in that, In SO3, concentrated hydrochloric acid was added dropwise overnight, followed by the addition of sodium bicarbonate to quench the reaction. The volume ratio of the mixed solvent was dichloromethane: anhydrous ethanol = 1:1.