Application of SCQDs quenching type fluorescent probe in field of Fe < 3 + > detection

Abstract

The invention relates to the technical field of chemical application, in particular to application of an SCQDs quenching type fluorescent probe in the field of Fe < 3 + > detection. When the SCQDs quenching type fluorescent probe disclosed by the invention acts with Fe < 3 + >, the fluorescence intensity is obviously reduced, the addition of coexisting metal ions does not cause obvious change, F / F0 is still maintained at a relatively low level, and the quenching type fluorescent probe SCQDs disclosed by the invention shows excellent anti-interference capability.

Description

Technical Field

[0001] The present invention relates to the field of chemical application technology, and in particular to a SCQDs quenching type fluorescent probe in Fe 3+ Applications in the field of detection. Background Art

[0002] Fe 3+ It is commonly found in natural water bodies. 3+ It may accumulate in the form of dissolution or sedimentation, thus posing a potential threat to aquatic ecosystems. 3+ The concentration in aquaculture water gradually increases, which in turn has a certain impact on aquaculture water. 3+ It is easy to react with carbonate and hydroxide ions in water to form iron hydroxide precipitation, which makes the water appear brown or brown turbid, reduces the transparency of the water, hinders light penetration, and thus interferes with the photosynthesis of phytoplankton. 3+ The products and precipitates formed after oxidation are very likely to accumulate on the surface of fish gill tissue, forming characteristic "rust-like" deposits. This deposition will seriously interfere with the normal gas exchange function of the gills. At the same time, Fe 3+ Increased concentrations may also induce stress responses in fish and crustaceans, causing them to eat less, grow slower, and have lower immune function. Long-term exposure to high concentrations of Fe 3+ In the environment, it will interfere with the endocrine system of aquatic animals, inhibit reproductive function, affect embryonic development, and reduce the reproductive capacity of the population.

[0003] Fe 3+ It has a significant regulatory effect on the structure of algae populations. 3+ It can significantly promote the proliferation of Chlorella pyrenoidosa, making its biomass reach 80 times of the initial concentration; however, when Fe 3+ When the concentration exceeds a certain threshold, it will inhibit the growth of algae, causing them to stagnate and even die. In addition, different types of algae have different sensitivities and absorption capacities to iron. 3+ Fe levels may change the competition pattern among algae, disrupt the original community balance, induce the dominance of iron-resistant species such as cyanobacteria, and then cause algal blooms and eutrophication of water bodies. 3+ By regulating the production of extracellular secretions in the algae-bacteria symbiotic system, the adhesion characteristics of microorganisms in water and the stability of their community structure are changed. 3+ It will drive the growth of some pathogenic bacteria such as Vibrio, increasing the probability of animals in aquaculture suffering from infectious diseases. Summary of the Invention

[0004] In view of the above problems, the present invention provides a SCQDs quenching type fluorescent probe in Fe 3+Applications in the field of detection.

[0005] On the other hand, the present invention provides a SCQDs quenching type fluorescent probe for detecting Fe 3+ method.

[0006] In some embodiments, the SCQDs quenching fluorescent probe of the present invention detects Fe 3+ In the method, the concentration of the SCQDs quenching fluorescent probe is 0.05 mg / mL.

[0007] In some embodiments, the SCQDs quenching fluorescent probe of the present invention detects Fe 3+ In the method, the pH in the detection system is 6.

[0008] In some embodiments, the SCQDs quenching fluorescent probe of the present invention detects Fe 3+ In the method, the SCQDs are Fe 3+ The detection limit was 1.24 μM.

[0009] On the other hand, the present invention provides a SCQDs quenched fluorescent probe detection kit, which includes a SCQDs quenched fluorescent probe.

[0010] In some embodiments, the concentration of the SCQDs quenched fluorescent probe in the SCQDs quenched fluorescent probe detection kit is 0.05 mg / mL.

[0011] On the other hand, the present invention provides the SCQDs quenching type fluorescent probe detection kit in Fe 3+ Applications in the field of detection.

[0012] The SCQDs quenching fluorescent probe of the present invention and Fe 3+ When exposed to the presence of metal ions, the fluorescence intensity decreased significantly, the addition of coexisting metal ions did not cause significant changes, and F / F0 remained at a low level. The quenched fluorescent probe SCQDs of the present invention exhibited excellent anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The SCQDs quenching type fluorescent probe for Fe in Example 2 3+ Selective detection.

[0014] Figure 2 The effects of solution pH and response time on the fluorescence quenching effect of SCQDs in Example 3. (a) is the optimal pH; (b) is the detection response time.

[0015] Figure 3 The SCQDs quenching type fluorescent probe in Example 4 reacts with different concentrations of Fe3+ Fluorescence response curve of (5-500μM).

[0016] Figure 4 The SCQDs quenching type fluorescent probe for Fe in Example 5 3+ Detection of anti-interference detection. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0018] The instruments and solvents used in the present invention are all conventional reagents and can be purchased commercially.

[0019] Table 1

[0020]

[0021]

[0022] Table 2: Experimental instruments and models used in the present invention.

[0023] Table 2 Summary of experimental instruments

[0024]

[0025] Copper algae: comes from the copper algae breeding base in Changdao, Yantai, Shandong.

[0026] Example 1 Preparation of SCQDs Quenched Fluorescent Probe

[0027] (1) Pretreatment of Copper Algae: Wash the copper algae 3-4 times with deionized water, remove large impurities, and dry the cleaned copper algae in an oven at 80°C for 24 hours. After grinding it four times with a grinder, sieve it with a 100-mesh standard sieve to obtain 100-mesh copper algae powder. Take 0.5g of copper algae powder in a beaker, add 50mL of deionized water, and crush it in an ice bath using an ultrasonic crusher for 180min, sonicating for 3s each time with a 2s interval to obtain 50mL of copper algae homogenate.

[0028] (2) Preparation of copper algae-based carbon quantum dots: The copper algae homogenate (50 mL) prepared above was transferred to a 100 mL tetrafluoroethylene liner, placed in a high-pressure reactor, and hydrothermally pyrolyzed at 220°C for 18 h. The obtained pyrolysis solution was centrifuged at 10,000 r / min for 15 min, the supernatant was filtered with a 0.22 μm needle filter, and the filtrate was transferred to a 1000 molecular weight dialysis bag and dialyzed for 24 h. Deionized water was replaced every 8 h. After the dialysis, a carbon quantum dot solution SCQDs was obtained. It was freeze-dried for 48 h to obtain a powder, which was prepared into a 0.05 mg / mL SCQDs solution with deionized water to obtain a 0.05 mg / mL SCQDs quenched fluorescent probe.

[0029] Example 2Fe 3+ Selective detection

[0030] 16 common metal ions (Ca 2+ 、Ce 3+ 、Zn 2+ 、Ni 2+ , K + Mg 2+ 、Na + 、Cd 2+ 、Mn 2+ 、Co 2+ 、Cu 2+ Cr 3 + 、Al 3+ , Pb 2+ 、Hg 2+ and Fe 3+ ) aqueous solution 500 μmol / L (the concentration of each metal ion is 500 μmol / L). Take 1 mL of each metal ion solution and add it to 1 mL of the SCQDs solution (0.05 mg / mL) prepared in Example 1, and mix thoroughly for 5 minutes using a vortex mixer. Subsequently, the fluorescence intensity of each system is measured at an excitation wavelength of 360 nm, and the ratio is calculated. By comparing Fe 3+ The effect of other metal ions on the fluorescence intensity of SCQDs was evaluated. 3+ selective recognition ability.

[0031] Figure 1 The results show that SCQDs can be synthesized in 16 different metal ions (Ca 2+ 、Ce 3+ 、Zn 2+ 、Ni 2+ , K + Mg 2+ 、Na + 、Fe 3+ 、Cd 2 +、Mn 2+ 、Co 2+ 、Cu 2+ Cr 3+ 、Al 3+ , Pb 2+ 、Hg 2+ ) to evaluate the effect of SCQDs on Fe 3+ The results showed that Fe 3+ The fluorescence quenching of SCQDs was significant, and the F / F0 value dropped significantly to 0.17, indicating that SCQDs have a strong effect on Fe 3+ It is highly selective. Other metal ions have little effect on the fluorescence of SCQDs, and their F / F0 value is close to 1.0, indicating that SCQDs can be used as Fe 3+ Potential fluorescent probes for selective detection.

[0032] Example 3 Investigating the Effect of Solution pH and Response Time on Fluorescence Quenching

[0033] 0.1 mol / L hydrochloric acid or sodium hydroxide was added to the SCQDs solution to adjust the system pH to 1-14, and the fluorescence intensity of SCQDs under different pH conditions was measured to screen the optimal pH. Under the optimized pH conditions, 500 μmol / L Fe 3+ 1mL, record the fluorescence intensity change within 60min, and further determine the effect of SCQDs solution on Fe 3+ The best response time.

[0034] Figure 2 (a) shows the fluorescence intensity changes of SCQDs solutions under different pH conditions (1-14). When pH = 6, the fluorescence emission of SCQDs is the strongest, while under acidic or alkaline conditions, the fluorescence intensity decreases significantly. Under alkaline conditions, the luminescence of the -COOH functional group is suppressed, resulting in a decrease in fluorescence. In a strongly acidic environment, -NH3 is easily protonated, and SCQDs undergo a certain degree of aggregation, which further reduces their fluorescence emission intensity. Figure 2 (b) shows the effect of SCQDs on Fe 3+ The results show that SCQDs have a fluorescence response time of 3+ After that, the fluorescence intensity decreases rapidly and stabilizes within 5 seconds (F / F0 changes smoothly), showing good rapid response capability. This property gives SCQDs good application potential in environmental pollutant analysis and on-site rapid detection.

[0035] Example 4 Detection limit determination

[0036] Under the optimal pH conditions, 0.01-500 μmol / L Fe3+ Standard solution, take 1mL of each concentration solution and add it to 1mL of SCQDs solution prepared in Example 1. The fluorescence intensity of the system was measured at an excitation wavelength of 360nm, and the fluorescence intensity ratio (F / F0) was calculated. With (F0-F) / F0 as the vertical axis, Fe 3+ With concentration as the horizontal axis, draw the standard working curve and obtain its linear equation and correlation coefficient (R 2 In addition, the effect of SCQDs on Fe was calculated according to the formula LOD = 3σ / k (where σ is the standard deviation of the blank sample and k is the slope of the calibration curve). 3+ detection limit.

[0037] Figure 3 The results show that SCQDs have different Fe concentrations. 3+ (0-500μM) fluorescence response. The fluorescence intensity of SCQDs increases with the Fe 3+ The quenching effect of Fe0 was gradually weakened with the increase of concentration, showing a significant concentration-dependent quenching phenomenon. Linear fitting analysis showed that in the range of 0.01-100μM, the fluorescence intensity change value (F0-F) / F0 was closely related to the Fe0-F0. 3+ The concentration showed a good linear relationship (R 2 =0.995) is calculated according to the linear fitting formula (1)

[0038]

[0039] where σ is the standard deviation of 11 different standard samples, S is the fluorescence intensity of SCQDs and Fe 3+ The slope of the concentration standard curve, SCQDs to Fe 3+ The detection limit is 1.24 μM, showing high detection sensitivity. This fluorescent probe system can be used for low concentration Fe in actual water. 3+ It has good environmental monitoring and application potential.

[0040] Example 5 Anti-interference experiment

[0041] To evaluate the effect of SCQDs on Fe 3+ To test the anti-interference ability, 1 mL of 500 μmol / L Fe 3+ solution and 1 mL of equimolar concentrations of interfering metal ions (Ca 2+ 、Ce 3+ 、Zn 2+ 、Ni 2+ , K + Mg 2+ 、Na + 、Cd 2+ 、Mn2+ 、Co 2+ 、Cu 2+ Cr 3+ 、Al 3+ , Pb 2+ 、Hg 2+ , the concentration of each metal ion was 500 μmol / L), the fluorescence intensity change was measured, and the fluorescence intensity ratio (F / F0) was calculated. 3+ Existing alone with Fe 3+ The fluorescence quenching effect of SCQDs in the presence of other metal ions was further evaluated. 3+ The anti-interference ability of detection.

[0042] Figure 4 The results show that SCQDs can resist Fe under different coexisting metal ions. 3+ “Blank” represents the initial fluorescence intensity of SCQDs (SCQDs solution 1ml + equal volume of aqueous solution), 3+ In the presence of 2+ 、Ce 3+ 、Zn 2+ 、Ni 2+ , K + Mg 2+ 、Na + 、Cd 2+ 、Mn 2+ 、Co 2+ 、Cu 2+ Cr 3+ 、Al 3+ , Pb 2+ 、Hg 2+ The fluorescence intensity ratio was measured after adding metal ions. 3+ When exposed to light, the fluorescence intensity decreased significantly, the addition of coexisting metal ions did not cause obvious changes, and F / F0 remained at a low level, demonstrating the excellent anti-interference ability of SCQDs.

Claims

1. A SCQDs quenching fluorescent probe in Fe 3+ Applications in the field of detection.

2. A SCQDs-quenched fluorescent probe for Fe detection 3+ method.

3. Detection of Fe by SCQDs quenching fluorescent probe according to claim 2 3+ The method, wherein the concentration of the SCQDs quenching fluorescent probe is 0.05 mg / mL.

4. Detection of Fe by the SCQDs quenching fluorescent probe according to claim 2 3+ The method, wherein the pH in the detection system is 6.

5. Detection of Fe by the SCQDs quenching fluorescent probe according to claim 2 3+ The method described herein is to prepare SCQDs for Fe 3+ The detection limit was 1.24 μM.

6. A SCQDs quenching type fluorescent probe detection kit, the kit comprising a SCQDs quenching type fluorescent probe. 7 . The SCQDs quenched fluorescent probe detection kit according to claim 6 , wherein the concentration of the SCQDs quenched fluorescent probe is 0.05 mg / mL.

8. The SCQDs quenching fluorescent probe detection kit according to any one of claims 6-7 is used in Fe 3+ Applications in the field of detection.

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