A dissolved oxygen fluorescent chemical sensing material and its preparation and application

Abstract

The invention relates to a dissolved oxygen fluorescent chemical sensing material and its preparation and application, wherein the components include tris(4,7-biphenyl-1,10-phenanthroline)dichlororuthenium(II), alcohol and polydimethylsiloxane (PDMS). The dissolved oxygen fluorescent sensing film obtained by the invention has good uniformity, good sensing performance and good stability.

Description

Technical Field

[0001] The invention belongs to the field of sensing, and particularly relates to a dissolved oxygen fluorescent chemical sensing material and a preparation and application thereof. Background Art

[0002] As the external environment changes, the chemical or physical properties of the substance change, which causes the fluorescence signal to change under the same excitation light. Compared with traditional detection methods, fluorescent chemical sensors have the advantages of visualization, high sensitivity, fast detection speed, and simple and easy operation. At present, they have been widely used in environmental, biological, and medical detection fields.

[0003] Dissolved oxygen refers to oxygen dissolved in water. The dissolved oxygen content in general agricultural water is above 2 mg / L, and in clear rivers and lakes it is 6-8 mg / L. Detecting dissolved oxygen in water can ensure the normal operation of fishery breeding and product production, and can also reflect some environmental pollution events, such as "red tide". Therefore, dissolved oxygen detection is of great significance.

[0004] Tris(4,7-biphenyl-1,10-phenanthroline)dichlororuthenium(II) (Ru(dpp)3Cl2) is a common oxygen-sensitive substance that emits orange fluorescence under 450nm excitation light, with an emission peak at 610nm. In addition, its fluorescence intensity decreases significantly with the increase of oxygen content, so it is often used to detect oxygen content. Polydimethylsiloxane (PDMS) is an inexpensive elastomer with good biocompatibility, stability and high transparency (≥90%). However, the current single PDMS system has poor air permeability, and Ru(dpp)3Cl2 cannot be evenly dispersed in the PDMS system, making it impossible to detect the dissolved oxygen content in water. Summary of the invention

[0005] In view of the defects of the prior art, the technical problem to be solved by the present invention is to provide a dissolved oxygen fluorescent chemical sensing material and its preparation and application. The present invention solves the current problem of poor dispersibility and poor sensing performance of Ru(dpp)3Cl2 in polydimethylsiloxane (PDMS).

[0006] The present invention provides a sensing material, which comprises the following components by weight:

[0007]

[0008] Preferably, the alcohol is one or more of ethanol and silanol; the silanol is one or more of trimethylsilanol, triethylsilanol, tert-butyldimethylsilanol, triisopropylsilanol, dimethyl(thiophen-2-yl)silanol, diethyl(isopropyl)silanol, and diphenylsilanol.

[0009] More preferably, the silanol is triethylsilanol and tert-butyldimethylsilanol in a mass ratio of 1:10 to 10:1.

[0010] Preferably, the crosslinking agent is a fluorine-containing substance; the fluorine-containing substance is one or more of (3,3,3-trifluoropropyl)trimethoxysilane, di-tert-butyldifluorosilane, 3-aminopropyldimethylfluorosilane, 3,3,3-trifluoropropyltriethoxysilane, triethylfluorosilane, and tridecafluorooctyltriethoxysilane.

[0011] Preferably, the polydimethylsiloxane PDMS comprises a prepolymer A and a crosslinking agent B; the catalyst is one or more of formic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, sodium hydroxide, potassium hydroxide, and ammonia water.

[0012] Furthermore, the mass ratio of the prepolymer A to the crosslinking agent B is 1:1.

[0013] By weight, the components include:

[0014]

[0015] The present invention provides a method for preparing any of the above-mentioned sensing materials, comprising:

[0016] Polydimethylsiloxane PDMS, tri(4,7-biphenyl-1,10-phenanthroline) dichlororuthenium (II), alcohol, a crosslinking agent and a catalyst are mixed, stirred, ultrasonicated, degassed and cured.

[0017] The preparation method comprises: mixing tri(4,7-biphenyl-1,10-phenanthroline)ruthenium(II) dichloride and alcohol to obtain fluorescent liquid, then mixing with polydimethylsiloxane (PDMS), a crosslinking agent and a catalyst, stirring, ultrasonicating, degassing and curing.

[0018] The curing is carried out in a mold.

[0019] Preferably, the ultrasound is performed at room temperature for 0 to 60 minutes.

[0020] Preferably, the degassing is performed under vacuum at room temperature and -0.05Mpa to -0.1Mpa.

[0021] Preferably, the curing is performed at 60-120° C. for 6-48 hours.

[0022] The invention provides a dissolved oxygen fluorescent chemical sensing membrane, wherein the sensing membrane contains the sensing material.

[0023] The invention provides an application of the sensing material in dissolved oxygen determination.

[0024] The present invention provides a dissolved oxygen determination method, comprising: adding a liquid to be measured into a container (such as a membrane tool) equipped with a dissolved oxygen fluorescence sensor membrane, irradiating the dissolved oxygen fluorescence sensor with 450nm excitation light after 10-30min (preferably 30min), and determining the emission light intensity at 610nm, wherein the emission light intensity at 610nm is directly related to the dissolved oxygen concentration in the liquid, and wherein the emission light intensity and the dissolved oxygen concentration are negatively correlated.

[0025] Beneficial Effects

[0026] The present invention utilizes Ru(dpp)3Cl2 mixed with PDMS to prepare a dissolved oxygen fluorescent chemical sensing membrane.

[0027] The method of the invention has the characteristics of simple operation, short curing time and mild reaction.

[0028] The dissolved oxygen fluorescent chemical sensing membrane of the present invention has the characteristics of good uniformity, excellent sensing performance and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 . SEM images of the surface of dissolved oxygen fluorescent chemical sensing membrane (a) Example 1, (b) Example 2, (c) Example 3, (d) Example 4, (e) Example 5;

[0030] Figure 2 . EDS images of the surface of dissolved oxygen fluorescent chemical sensing membrane (a) Example 1, (b) Example 2, (c) Example 3, (d) Example 4, (e) Example 5;

[0031] Figure 3 .Contact angle diagram of dissolved oxygen fluorescent chemical sensing film (a) Example 1, (b) Example 2, (c) Example 3, (d) Example 4, (e) Example 5;

[0032] Figure 4 .UV-vis spectrum of dissolved oxygen fluorescence chemical sensing membrane;

[0033] Figure 5 . Fluorescence spectra of dissolved oxygen fluorescent chemical sensing membrane (a) Example 1, (b) Example 2, (c) Example 3, (d) Example 4, (e) Example 5;

[0034] Figure 6 .Example 3 Fluorescence spectra in oxygen-free water environment on the day and the tenth day after curing.

[0035] Figure 7.(a) Fluorescence spectra of Example 3 at different dissolved oxygen contents (8.25, 5.89, 3.53 mg / L); (b) Linear relationship between fluorescence intensity at 610 nm and dissolved oxygen content. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0037] Sources of main raw materials;

[0038] PDMS (A and B glue) is an optical grade liquid silica gel of model BESIL 8250A / B; tris(4,7-biphenyl-1,10-phenanthroline) dichloride ruthenium (II) was purchased from Adamas Company.

[0039] Related tests:

[0040] The transparency of the sensor was characterized by using a UV-visible near-infrared spectrometer (UV-vis) with a model of UV3600. The scanning mode was transmittance (%), integrating sphere test; the scanning range was 325-1100 nm.

[0041] Fluorescence spectroscopy uses a QM / TM fluorescence spectrometer (PL) to detect the fluorescence intensity of the sensor in the presence and absence of oxygen. The specific test parameters are: excitation wavelength: λ = 450nm, measurement range: 500-750nm, where oxygen-free water is 0.12g / mL sodium sulfite solution, and saturated dissolved oxygen water is deionized water that has been exposed to oxygen in the air for 3 days at room temperature 25°C. 无氧水 / I 饱和溶解氧水 It is the ratio of the fluorescence intensity of the sensing membrane at 610 nm in oxygen-free water and in a saturated dissolved oxygen environment.

[0042] Contact Angle The water contact angle of the sensor was determined using an OCA40Micro contact angle meter (CA), and the single extrusion water volume was set to 3 μL.

[0043] SEM A scanning electron microscope (SEM) of model SU8010 was used to characterize the microscopic morphology of the sensor. The sample preparation process was as follows: double-sided conductive adhesive was attached to the sample stage, the sample was cut into a suitable size and attached to the conductive adhesive, and gold was sprayed before the experiment for 120 seconds. Energy dispersive X-ray spectroscopy (EDS) was also performed on SU8010 to characterize the element distribution of the sensor, and the test element was Ru.

[0044] Example 1

[0045] Select a clean glass bottle, add 1 part of each component A and B of the two-component PDMS, and stir evenly. Then mix 0.0005 parts of Ru(dpp)3Cl2 with 0.25 parts of ethanol and add them to the bottle. You can see that the fluorescent liquid gathers on the surface of PDMS with obvious stratification. Use a glass rod to stir the mixture of the above substances evenly. You can see that the fluorescent liquid gradually dissolves, and the mixture as a whole presents a transparent red-orange solution state. Ultrasonicate it at an ultrasonic power of 150W and room temperature for 10 minutes. Then vacuum degassing at room temperature and -0.09Mpa, you can see a large number of bubbles emerging from the solution, and no bubbles appear in the solution after 2 to 3 minutes. Transfer the solution to a membrane mold and cure it in a blast oven at 80°C for 24 hours. After curing, an overall transparent, uniform, light yellow dissolved oxygen fluorescent chemical sensing membrane is obtained. From the SEM image ( Figure 1 In a), it can be observed that the surface of the sensing film has obvious wrinkles and no obvious defects. Then the EDS image of Ru element ( Figure 2 a) proves that the fluorescent substance (Ru(dpp)3Cl2) is evenly dispersed in the PDMS matrix. Contact angle image ( Figure 3 a) shows that when ethanol is used, the sensing membrane is more hydrophilic as a whole, and its contact angle is 86.3°. UV-vis spectrum ( Figure 4 ) showed that the sensing film had a certain transparency (≥20%) under visible light. Figure 5 a is the fluorescence spectrum of Example 1, and its fluorescence contrast ratio in an anaerobic / oxygen environment is only 1.16.

[0046] Example 2

[0047] Select a clean glass bottle, add 1 part of each component A and B of the two-component PDMS, and stir evenly. Then mix 0.0005 parts of Ru(dpp)3Cl2 and 0.25 parts of triethylsilanol and add them to the bottle. You can see that the fluorescent liquid gathers on the surface of PDMS with obvious stratification. Use a glass rod to stir the mixture of the above substances evenly. You can see that the fluorescent liquid gradually dissolves, and the mixture as a whole presents a transparent red-orange solution state. Ultrasonicate it at an ultrasonic power of 150W and room temperature for 10 minutes. Then vacuum degassing at room temperature and -0.09Mpa, you can see a large number of bubbles emerging from the solution, and no bubbles appear in the solution after 2 to 3 minutes. Transfer the solution to a membrane mold and cure it in a blast oven at 80°C for 24 hours. After curing, an overall transparent, uniform, light yellow dissolved oxygen fluorescent chemical sensing membrane is obtained. From the SEM image ( Figure 1 b), it can be observed that the surface of the sensing membrane has obvious wrinkles and no obvious defects. Then the EDS image of Ru element ( Figure 2b) proves that the fluorescent substance (Ru(dpp)3Cl2) is evenly dispersed in the PDMS matrix. Contact angle image ( Figure 3 b) shows that the sensing film has obvious hydrophobicity, and its contact angle is 101.2°. UV-vis spectrum ( Figure 4 ) shows that the sensing film has good transparency under visible light, and the transmittance can reach more than 90% above 550nm. Figure 5 b is the fluorescence spectrum of Example 2, and its fluorescence contrast ratio in an anaerobic / oxygen environment reaches 3.43.

[0048] Example 3

[0049] Select a clean glass bottle, add 1 part of each of the A and B components of the two-component PDMS, and stir evenly. Then mix 0.00055 parts of Ru(dpp)3Cl2 with 0.25 parts of tert-butyldimethylsilanol and 0.025 parts of triethylsilanol and add them to the bottle. You can see that the fluorescent liquid gathers on the surface of PDMS with obvious stratification. Then add 0.083 parts of (3,3,3-trifluoropropyl)trimethoxysilane to the glass bottle, and then add 0.42 parts of acetic acid. Use a glass rod to stir the mixture of the above substances evenly. You can see that the fluorescent liquid gradually dissolves, and the mixture as a whole presents a transparent light reddish orange solution state. Ultrasonicate it at an ultrasonic power of 150W and room temperature for 10 minutes. Then vacuum degassing at room temperature and -0.09Mpa, you can see a large number of bubbles coming out of the solution, and no bubbles appear in the solution after 2 to 3 minutes. Transfer the solution to the membrane and control the humidity in the blast oven between 45 and 85%. The film was placed in a forced air oven and cured at 80°C for 24 hours. After curing, a transparent and uniform dissolved oxygen fluorescent chemical sensing film with a light yellow color was obtained. From the SEM image ( Figure 1 c), it can be observed that the surface of the sensing membrane has obvious wrinkles and no obvious defects. Then the EDS image of Ru element ( Figure 2 c) proves that the fluorescent substance (Ru(dpp)3Cl2) is evenly dispersed in the PDMS matrix. Contact angle image ( Figure 3 c) shows that the sensing film has obvious hydrophobicity, and its contact angle is 110.8°. UV-vis spectrum ( Figure 4 ) shows that the sensing film has good transparency under visible light, and the transmittance can reach more than 90% above 550nm. Figure 5 c is the fluorescence spectrum of Example 3, and its fluorescence contrast ratio in anaerobic / oxygen environment is 5.18. Then the stability of the dissolved oxygen sensor membrane was characterized. Figure 6 It can be seen that the fluorescence intensity of the sensing membrane hardly changes in an anaerobic environment 10 days after preparation, proving that it has good stability. Figure 7The fluorescence spectra of Example 3 at different dissolved oxygen contents and the linear relationship between the fluorescence intensity at 610 nm and the dissolved oxygen content show that the dissolved oxygen content and the fluorescence intensity present an approximately linear relationship, and the linear equation is Y=76795-5872x, R 2 =0.968.

[0050] Example 4

[0051] Select a clean glass bottle, add 1 part of each of the A and B components of the two-component PDMS, and stir evenly. Then mix 0.0005 parts of Ru(dpp)3Cl2 and 0.25 parts of tert-butyldimethylsilanol and add them to the bottle. You can see that the fluorescent liquid gathers on the surface of PDMS with obvious stratification. Use a glass rod to stir the mixture of the above substances evenly. You can see that the fluorescent liquid gradually dissolves, and the mixture as a whole presents a transparent light reddish orange solution state. Ultrasonicate it at an ultrasonic power of 150W and room temperature for 10 minutes. Then vacuum degassing at room temperature and -0.09Mpa, you can see a large number of bubbles emerging from the solution, and no bubbles appear in the solution after 2 to 3 minutes. Transfer the solution to the membrane mold, and control the humidity in the blast oven between 45 and 85%. Place the membrane mold in a blast oven and cure it at 80°C for 24 hours. After curing, an overall transparent, uniform, light yellow dissolved oxygen fluorescent chemical sensing membrane is obtained. From the SEM image ( Figure 1 d), it can be observed that the surface of the sensing membrane has obvious wrinkles and no obvious defects. Then the EDS image of Ru element ( Figure 2 d) It proves that the fluorescent substance (Ru(dpp)3Cl2) is evenly dispersed in the PDMS matrix. Contact angle image ( Figure 3 d) shows that the sensing film has obvious hydrophobicity, and its contact angle is 118.5°. UV-vis spectrum ( Figure 4 ) shows that the sensing film has good transparency under visible light, and the transmittance can reach more than 90% above 550nm. Figure 5 d is the fluorescence spectrum of Example 4, whose fluorescence contrast ratio in an anaerobic / oxygen environment reaches 1.63.

[0052] Example 5

[0053] Select a clean glass bottle, add 1 part of each of the A and B components of the two-component PDMS, and stir evenly. Then mix 0.0005 parts of Ru(dpp)3Cl2 and 0.25 parts of triethylsilanol and add them to the bottle. You can see that the fluorescent liquid gathers on the surface of PDMS with obvious stratification. Then add 0.083 parts of (3,3,3-trifluoropropyl)trimethoxysilane to the glass bottle, and then add 0.42 parts of acetic acid. Use a glass rod to stir the mixture of the above substances evenly. You can see that the fluorescent liquid gradually dissolves, and the mixture as a whole presents a transparent light reddish orange solution state. Ultrasonicate it at an ultrasonic power of 150W and room temperature for 10 minutes. Then vacuum degassing at room temperature and -0.09Mpa, you can see a large number of bubbles coming out of the solution, and no bubbles appear in the solution after 2 to 3 minutes. Transfer the solution to the film mold and control the humidity in the blast oven between 45 and 85%. Put the film mold in a blast oven and cure it at 80℃ for 24 hours. After curing, a transparent and uniform dissolved oxygen fluorescent chemical sensing film with a light yellow color was obtained. Figure 1 e), it can be observed that the surface of the sensing membrane has obvious wrinkles and no obvious defects. Then the EDS image of Ru element ( Figure 2 e) It proves that the fluorescent substance (Ru(dpp)3Cl2) is evenly dispersed in the PDMS matrix. Contact angle image ( Figure 3 e) shows that the sensing film has obvious hydrophobicity, and its contact angle is 118.9°. UV-vis spectrum ( Figure 4 ) shows that the sensing film has good transparency under visible light, and the transmittance can reach more than 90% above 550nm. Figure 5 e is the fluorescence spectrum of Example 5, and its fluorescence contrast ratio in an anaerobic / oxygen environment reaches 2.61.

[0054] Table 1 Comparison of fluorescence intensity at 610 nm of different embodiments (I 无氧水 / I 饱和溶解氧水 )

[0055] Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[I 无氧水 / I 饱和溶解氧水 ]]> 1.16 3.43 5.18 1.63 2.61

Claims

1. A sensing material, characterized in that: By weight, the components include: The alcohol is one of trimethylsilanol, triethylsilanol, triisopropylsilanol, dimethyl(thiophen-2-yl)silanol, diethyl(isopropyl)silanol, and diphenylsilanol, or the silanol is triethylsilanol and tert-butyldimethylsilanol, and the mass ratio is 1:10 to 10:

1.

2. The sensing material according to claim 1, characterized in that: The crosslinking agent is a fluorine-containing substance; the fluorine-containing substance is one or more of (3,3,3-trifluoropropyl)trimethoxysilane, di-tert-butyldifluorosilane, 3-aminopropyldimethylfluorosilane, 3,3,3-trifluoropropyltriethoxysilane, triethylfluorosilane, and tridecafluorooctyltriethoxysilane.

3. The sensing material according to claim 1, characterized in that: The polydimethylsiloxane PDMS comprises a prepolymer A and a crosslinking agent B; the catalyst is one or more of formic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, sodium hydroxide, potassium hydroxide, and ammonia water.

4. The sensing material according to claim 1, characterized in that: By weight, the components include:

5. A method for preparing the sensing material according to any one of claims 1 to 4, comprising: Polydimethylsiloxane PDMS, tri(4,7-biphenyl-1,10-phenanthroline) dichlororuthenium (II), alcohol, a crosslinking agent and a catalyst are mixed, stirred, ultrasonicated, degassed and cured.

6. The preparation method according to claim 5, characterized in that: The ultrasonic treatment is carried out at room temperature for 0 to 60 minutes; the degassing is carried out at room temperature and vacuum degassing at -0.05Mpa to -0.1Mpa; The curing is carried out at 60 to 120° C. for 6 to 48 hours.

7. A dissolved oxygen fluorescent chemical sensing membrane, characterized in that: The sensing film contains the sensing material according to claim 1.

8. Use of the sensing material according to claim 1 in dissolved oxygen determination.

9. A method for determining dissolved oxygen, comprising: The liquid to be tested is added into a container containing a dissolved oxygen fluorescence sensor membrane. After 10-30 minutes, the dissolved oxygen fluorescence sensor is irradiated with 450nm excitation light and the emission light intensity at 610nm is measured. The emission light intensity at 610nm is directly related to the dissolved oxygen concentration in the liquid.

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