Carbon quantum dots synthesized based on gordon euryale seed hydrothermal method and application of carbon quantum dots in detection of Fe < 3 + > and Cu < 2 + >
Carbon quantum dots synthesized by Gorgon hydrothermal method use the fluorescence quenching effect to solve the problem of difficulty in rapid detection of Fe3+ and Cu2+ in water in the existing technology, and achieve rapid and sensitive detection of these heavy metal ions.
Patent Information
- Application Number
- CN202411579417.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-01-24
AI Technical Summary
The prior art is difficult to quickly and conveniently detect heavy metal ions Fe3+ and Cu2+ in water, which pose a threat to aquatic organisms and human health.
Carbon quantum dots were synthesized using Gorgon hydrothermal method, and through their fluorescence quenching effect on Fe3+ and Cu2+, rapid detection of these heavy metal ions was achieved.
The fast and sensitive detection of Fe3+and CU2+has good selectivity and can accurately detect these heavy metal ions within a lower concentration range.
Smart Images
Figure CN119351093A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of preparation of carbon quantum dots, and in particular to a carbon quantum dot synthesized by hydrothermal method based on Euryale ferox and a method for detecting Fe 3+ , Cu 2+ application. Background Art
[0002] Water pollution caused by heavy metal ions has become a serious problem. Heavy metal ions not only have toxic side effects on aquatic organisms, but can also accumulate through the food chain and cause harm to the human body. Therefore, it is necessary to quickly and conveniently detect metal ions Fe 3 + , Cu 2+ Iron is one of the trace elements required by the human body. It has a certain content and proportion in the human body, but excessive absorption of iron ions may cause a series of diseases and even reduce intelligence. Copper is one of the trace elements necessary for the human body. It plays an important role in life activities such as cell metabolism and mitochondrial respiration. However, excessive intake of copper ions can cause acute poisoning in the human body and affect the functions of the liver and kidneys. Summary of the invention
[0003] The present invention provides a carbon quantum dot synthesized by hydrothermal method based on Euryale ferox and its detection Fe 3+ , Cu 2+ application.
[0004] In order to achieve the above object, the technical solution adopted by the present invention is:
[0005] The first aspect of the present invention provides a method for preparing carbon quantum dots, comprising the following steps:
[0006] Pour the Euryale ferox powder into a reaction kettle, add distilled water, stir, perform hydrothermal reaction, then centrifuge and filter to obtain Euryale ferox fluorescent carbon quantum dot mother liquor, and store it in the dark.
[0007] Preferably, the mass ratio of the gorgon fruit powder to distilled water is 1:(60-75); further preferably, the mass ratio of the gorgon fruit powder to distilled water is 1:(65-70).
[0008] Preferably, the temperature of the hydrothermal reaction is 200-280°C; further preferably, the temperature of the hydrothermal reaction is 230-250°C.
[0009] Preferably, the hydrothermal reaction time is 6-10 h; further preferably, the hydrothermal reaction time is 7-9 h.
[0010] Preferably, the centrifugal rotation speed is 8000-12000r / min.
[0011] Preferably, the number of centrifugation is 1-3 times, and the time of each centrifugation is 4-6 minutes.
[0012] Preferably, the filtration is carried out using a 0.22 μm filter membrane.
[0013] The second aspect of the present invention provides a carbon quantum dot prepared by the carbon quantum dot preparation method.
[0014] Preferably, the particle size of the carbon quantum dots is 3-6 nm.
[0015] Preferably, the carbon quantum dots contain C, N and O elements, wherein the mass fraction of the C element is 30-35%, the mass fraction of the N element is 8-15%, and the mass fraction of the O element is 50-60%.
[0016] The third aspect of the present invention provides the carbon quantum dots for detecting Fe 3+ , Cu 2+ Application in.
[0017] Preferably, the Fe 3+ The detection concentration range is 2×10 -7 ~1×10 -6 mol / L; Cu 2+ The detection concentration range is 2×10 -6 ~1×10 -5 mol / L.
[0018] A fourth aspect of the present invention provides a method for detecting Fe 3+ Cu 2+ The method comprises the following steps:
[0019] (1) Take the Euryale ferox fluorescent carbon quantum dot mother solution, measure its fluorescence intensity at 360nm, and then add a known concentration of standard Fe 3+ Cu 2+ The fluorescence intensity of the solution was measured at different concentrations to obtain the fluorescence intensity ratio F / F0 and Fe 3+ , Cu 2 + Linear relationship of concentration;
[0020] (2) Add the test solution to the Euryale ferox fluorescent carbon quantum dot mother solution to obtain the fluorescence intensity ratio, and convert it to obtain Fe 3+ Cu 2+ concentration.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] The present invention adopts the hydrothermal method to prepare carbon quantum dots, which can quickly and conveniently detect metal ions Fe 3+, Cu 2 + , its effect on Fe 3+ , Cu 2+ There is good selectivity. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is the fluorescence emission spectrum of E-CDs;
[0024] Figure 2 TEM images of E-CDs;
[0025] Figure 3 is the XPS graph of E-CDs;
[0026] Figure 4 is the FTIR graph of E-CDs;
[0027] Figure 5 The influence of common ions on the fluorescence intensity of E-CDs;
[0028] Figure 6 E-CDs carbon quantum dots for Fe 3+ Fluorescence quenching diagram of
[0029] Figure 7 E-CDs carbon quantum dots to Cu 2+ Fluorescence quenching diagram. DETAILED DESCRIPTION
[0030] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0031] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.
[0032] Example 1
[0033] This embodiment provides a method for preparing fluorescent carbon quantum dots from Euryale ferox, the specific process comprising the following steps:
[0034] Take an appropriate amount of Gorgon and grind it into Gorgon powder with a grinder. Weigh 0.9g of the ground Gorgon powder, pour it into a 100mL reactor, add 60mL of distilled water, add a stirrer and place the stirrer, stir for 30 minutes; take out the stirrer from the stirred Gorgon solution, cover the reactor, put it in a drying oven, and heat it at 240℃ for 8h. After the heating stops, take out the yellow carbon quantum dot solution, pour it into two 100mL centrifuge tubes, put it in a centrifuge, set the parameters to 10000r / min and centrifuge twice, five minutes each time; after the centrifugation is completed, use a 0.22μm filter membrane to filter the supernatant and inject it into a 15mL centrifuge tube. The dispersion obtained by the above steps is the mother liquor of Gorgon fluorescent carbon quantum dots, which needs to be kept away from light. The mother liquor of Gorgon fluorescent carbon quantum dots is referred to as E-CDs below.
[0035] Take 3ml E-CDs in a fluorescence cuvette, and increase the incident wavelength by 10nm from 300nm to 400nm as the excitation wavelength. The emission spectrum is shown in the attached figure. Figure 1 As shown. Figure 1 It can be seen that the fluorescence intensity of E-CDs is the highest at an excitation wavelength of 360 nm. Therefore, the optimal excitation wavelength of E-CDs is 360 nm.
[0036] TEM characterization of E-CDs Figure 2 As shown in the figure, it can be seen that the size of E-CDs is uniform and the dispersion is good, and the average particle size is about 4.5nm.
[0037] The elemental composition of the fluorescent carbon quantum dots was analyzed and characterized by X-ray photoelectron spectroscopy. The experimental results are as follows Figure 3 As shown in the XPS graph, it can be seen that the fluorescent carbon quantum dots of the O1s peak appear at 532.18eV, the fluorescent carbon quantum dots of the N1s peak appear at 399.68eV, and the fluorescent carbon quantum dots of the C1s peak appear at 285.78eV. It can be seen that the surface of this material contains three elements, C, N and O, with mass fractions of 33.48%, 11.58% and 54.94% respectively.
[0038] The chemical bonds of the synthesized E-CDs were characterized by FTIR spectroscopy, such as Figure 4 As shown. 3510.49cm in the figure -1 The OH / NH stretching vibration absorption peak at 1651.06cm indicates that it has good water solubility. -1 The characteristic absorption band at is the aromatic CN heterocycle.
[0039] Prepare 0.1 mol / L lactose, melamine, KCl, NaCl, HgCl2, CaCl2, CdCl2, CoCl2, CuCl2, FeCl3, BaCl2 solutions as interferences, first add 3 mL of E-CDs to the fluorescence cuvette, measure the emission spectrum and fluorescence intensity of the blank sample at an excitation wavelength of 360 nm, then take 3 μL of each of the above solutions and add them to the fluorescence cuvette containing 3 mL of E-CDs solution, mix evenly for 3 minutes, and then perform fluorescence detection. And compare the fluorescence intensity of E-CDs after adding interferences with the fluorescence intensity of the corresponding blank E-CDs ( Figure 5 ).like Figure 5 As shown, Fe 3+ , Cu 2+ The fluorescence intensity of E-CDs is well quenched, while the quenching effect of other interfering substances is not obvious and even increases fluorescence. Therefore, it can be judged that E-CDs has a good quenching effect on Fe 3+ , Cu 2+ There is good selectivity.
[0040] Different gradient Fe 3+ The effect of concentration on the fluorescence quenching of E-CDs is shown in Figure 6 As shown, Figure 6 From top to bottom, the corresponding Fe 3 + The concentration is 0mol / L, 2×10 -7 mol / L、4×10 -7 mol / L、6×10 -7 mol / L、8×10 -7 mol / L、10×10 -7 mol / L、3×10 -6 mol / L、5×10 -6 mol / L、7×10 -6 mol / L、9×10 -6 mol / L、2×10 -5 mol / L、4×10 -5 mol / L、6×10 -5 mol / L、8×10 -5 mol / L、10×10 -5 mol / L.
[0041] Different gradient Cu 2+ The effect of concentration on the fluorescence quenching of E-CDs is shown in Figure 7 As shown, Figure 7 From top to bottom, the corresponding Cu 2 + The concentration is 0mol / L, 2×10 -6mol / L、4×10 -6 mol / L、6×10 -6 mol / L、8×10 -6 mol / L、10×10 -6 mol / L、3×10 -5 mol / L、5×10 -5 mol / L、7×10 -5 mol / L、9×10 -5 mol / L.
[0042] Depend on Figure 6 , 7 It can be seen that the fluorescence intensity of CDs increases with the Fe 3+ , Cu 2+ The concentration of Fe 3+ From 2×10 - 7 mol / L to 1×10 -4 mol / L fluorescence was completely quenched, Cu 2+ From 2×10 -6 mol / L to 9×10 -5 mol / L fluorescence was completely quenched. At the same time, the fluorescence intensity ratio F0 / F and Fe 3+ , Cu 2+ The linear relationship between Fe 3+ In 2×10 -7 ~1×10 - 6 mol / L concentration range has a good linear relationship, Cu 2+ In 2×10 -6 ~1×10 -5 mol / L concentration range has a good linear relationship, indicating that this method is effective for Fe 3+ , Cu 2+ The detection is sensitive and rapid.
[0043] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.
Claims
1. A method for preparing carbon quantum dots, characterized in that: The following steps are involved: Pour the Euryale ferox powder into a reaction kettle, add distilled water, stir, perform hydrothermal reaction, then centrifuge and filter to obtain Euryale ferox fluorescent carbon quantum dot mother liquor, and store it in the dark.
2. The method for preparing carbon quantum dots according to claim 1, characterized in that: The mass ratio of the Euryale ferox powder to distilled water is 1:(60-75).
3. The method for preparing carbon quantum dots according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 200-280° C.; the time of the hydrothermal reaction is 6-10 hours.
4. The method for preparing carbon quantum dots according to claim 1, characterized in that: The centrifugal speed is 8000-12000 r / min; the number of centrifugation is 1-3 times, and the time of each centrifugation is 4-6 minutes.
5. The method for preparing carbon quantum dots according to claim 1, characterized in that: The filtration is carried out using a 0.22 μm filter membrane.
6. A carbon quantum dot, characterized in that The carbon quantum dots are prepared by the method for preparing the carbon quantum dots according to any one of claims 1 to 5.
7. The carbon quantum dots according to claim 6, characterized in that The particle size of the carbon quantum dots is 3-6 nm.
8. The carbon quantum dots according to claim 6, characterized in that The carbon quantum dots contain C, N and O elements, wherein the mass fraction of the C element is 30-35%, the mass fraction of the N element is 8-15%, and the mass fraction of the O element is 50-60%.
9. The carbon quantum dots according to any one of claims 6 to 8 are used to detect Fe 3+ , Cu 2+ Application in.
10. A method for detecting Fe 3+ or Cu 2+ The method is characterized in that The following steps are involved: (1) Take the mother solution of Euryale ferox fluorescent carbon quantum dots according to any one of claims 1 to 5, measure its fluorescence intensity at 360 nm, and then add a standard Fe 3+ or Cu 2+ The fluorescence intensity of the solution was measured at different concentrations to obtain the fluorescence intensity ratio F / F0 and Fe 3+ , Cu 2+ Linear relationship of concentration; (2) Add the test solution to the Euryale ferox fluorescent carbon quantum dot mother solution to obtain the fluorescence intensity ratio, and convert it to obtain Fe 3 + or Cu 2+ concentration.