CN112881350A - Preparation method of carbon quantum dots with carambola as carbon source and application of carbon quantum dots in copper ion detection - Google Patents
Preparation method of carbon quantum dots with carambola as carbon source and application of carbon quantum dots in copper ion detection Download PDFInfo
- Publication number
- CN112881350A CN112881350A CN201911201883.1A CN201911201883A CN112881350A CN 112881350 A CN112881350 A CN 112881350A CN 201911201883 A CN201911201883 A CN 201911201883A CN 112881350 A CN112881350 A CN 112881350A
- Authority
- CN
- China
- Prior art keywords
- carbon quantum
- quantum dots
- carbon
- copper ion
- carambola
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6402—Atomic fluorescence; Laser induced fluorescence
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
Landscapes
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Immunology (AREA)
- Analytical Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Pathology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
The invention discloses a preparation method of a carbon quantum dot using carambola as a carbon source and application of the carbon quantum dot in copper ion detection. According to the method, fresh carambola juice and polyethyleneimine are used as precursors, and a hydrothermal method is utilized to synthesize the amino-functionalized green fluorescent carbon quantum dots in one step. The method is simple and feasible, economical and green, the raw materials are low in price and environment-friendly, and the obtained product is subjected to PEI functionalization and has high quantum yield. The carbon quantum dot prepared by the method can be applied to detection of copper ions in water, and the detection method has the advantages of high selectivity, high sensitivity and low detection limit.
Description
Technical Field
The invention belongs to the technical field of metal ion detection, and relates to a preparation method for preparing carbon quantum dots by using carambola as a carbon source, and application of the carbon quantum dots in copper ion detection.
Background
The carbon quantum dots serving as the carbon nano material have the advantages of good light stability, good water solubility, up-conversion fluorescence emission, low biotoxicity and the like, and are widely applied to the fields of methanol fuel cells, environmental metal ion detection, sensors, cell imaging, drug transportation and the like. The raw materials for synthesizing the carbon quantum dots mainly comprise an artificially synthesized carbon-containing reagent and a natural plant carbon source. Chinese patent application CN104560035A discloses a carbon quantum dot fluorescent marking material using orange peel as a carbon source, wherein orange peel and water are mixed and stirred, then mixed liquid and concentrated sulfuric acid are mixed and stirred, then sodium hydroxide is used for adjusting pH value and removing residues through centrifugation, dichloromethane is added for removing nonfluorescent fat-soluble substances through centrifugation, and the fluorescent marking material is prepared at normal temperature. Chinese patent application CN105366659A discloses a method for hydro-thermally synthesizing carbon quantum dots based on fruits, wherein various fruits are used as raw materials for hydro-thermally synthesizing the carbon quantum dots, and the original carbon quantum dots prepared by the method have low fluorescence yield, so that the application of the carbon quantum dots is greatly limited. Therefore, it is necessary to provide a high-quality carbon source to prepare a carbon quantum dot having a high fluorescence quantum yield by a simple synthesis method.
Copper ions, the third most abundant transition metal ions in the human body, play a vital role in biological systems. As a coenzyme factor of many enzymes, the content of copper ions is too low or too high, which can have great influence on the living system of human body. At present, a plurality of methods for detecting copper ions mainly comprise an atomic absorption spectrometry method, an ion chromatography and chemiluminescence continuous use method, an inductively coupled plasma method, an electrochemical voltammetry method, a biochemical method and the like, and although the accuracy and the sensitivity of some methods can meet the requirements and the technology is mature, large-scale equipment is required, the detection time is long, the selectivity is poor, and the application of the methods is limited. The fluorescence probe method has gradually become a good substitute for ion detection due to its advantages of high sensitivity, easy operation, less spectral interference, wide absorption band, capability of absorbing multi-point emission at one point, and the like. Therefore, it is very meaningful to develop a copper ion detection method with high sensitivity and low biotoxicity to realize the detection of trace copper ions.
Disclosure of Invention
The invention aims to provide a preparation method of a carbon quantum dot using carambola as a carbon source and application of the carbon quantum dot in copper ion detection.
The technical scheme for realizing the purpose of the invention is as follows:
the method for preparing the carbon quantum dots by taking carambola as a carbon source comprises the following steps:
mixing and stirring fresh carambola juice and Polyethyleneimine (PEI), carrying out hydrothermal reaction at 120-180 ℃, filtering with a filter membrane after the reaction is finished, and dialyzing the filtrate to obtain the carbon quantum dots with amino functionalization.
Preferably, the hydrothermal reaction time is 10-12 h.
Preferably, the filtration is performed using a 0.22 μm microfiltration membrane.
Preferably, the dialysis uses a dialysis bag with the molecular weight of 1000Da and the dialysis time is 48 h.
The invention also provides the carbon quantum dots prepared by the method.
Further, the invention provides an application of the carbon quantum dot in copper ion detection, which comprises the following steps: adding the copper ion solution to be detected into the aqueous solution of the amino-functionalized carbon quantum dots, detecting the fluorescence intensity after the reaction is balanced, and calculating to obtain the concentration of the copper ions in the copper ion solution to be detected according to the linear relation between the fluorescence intensity and the concentration of the copper ions.
Preferably, the concentration of the aqueous solution of the carbon quantum dots is 0.05mg/ml, and the pH of the solution is 4.0-6.0;
preferably, the reaction time required for equilibration is 2 min.
Preferably, the excitation wavelength for detecting the fluorescence intensity is 353 nm.
Compared with the prior art, the invention has the following advantages:
the synthesis raw materials of the carbon quantum dots are cheap and easy to obtain, the method is simple and environment-friendly, the prepared carbon quantum dots are high in fluorescence quantum yield, instruments used by the quantum dots in the detection of copper ions are relatively cheap, the reagent consumption is low, the time consumption is low, and the method is good in accuracy and reproducibility.
Drawings
FIG. 1 is a fluorescence spectrum of a carbon quantum dot whose fluorescence intensity varies with the concentration of copper ions.
FIG. 2 is a linear graph showing the fluorescence intensity of carbon quantum dots as a function of the concentration of copper ions.
FIG. 3 is a graph showing the effect of different pH values on the fluorescence intensity of a carbon quantum dot-copper ion system.
FIG. 4 is a graph showing the effect of reaction time on the fluorescence intensity of a carbon quantum dot-copper ion system.
FIG. 5 is a graph showing the results of specificity for detecting copper ions in the presence of different kinds of metal ions.
Detailed Description
The present invention will be described in more detail with reference to the following examples and the accompanying drawings.
Example 1
(1) Preparing an amino-functionalized carbon quantum dot: fresh carambola was juiced by placing it in a juicer, mixing and dissolving 20ml of carambola juice and 0.5ml of PEI in a 50ml beaker, and then transferring the mixed liquid to a 100ml teflon-lined reaction vessel and carrying out hydrothermal reaction at 160 ℃ for 10 hours. After completion of the reaction, it was cooled to room temperature, and the tan product was filtered three times through a 0.22 μm filter to remove unreacted particles. Thereafter, the solution was transferred to dialysis in dialysis bags (molecular weight 1000Da) for 48 hours and freeze-dried.
(2) Preparing solutions containing carbon quantum dots and copper ions with different concentrations. 2ml of an aqueous solution of carbon quantum dots (pH 4) was added to a quartz cuvette, and then copper ion solutions of different concentrations were sequentially added so that the concentration of copper ions was 0. mu.M, 2. mu.M, 5. mu.M, 8. mu.M, 10. mu.M, 15. mu.M, 20. mu.M, 25. mu.M, 30. mu.M, 35. mu.M, 40. mu.M, 45. mu.M, 55. mu.M, 65. mu.M, 75. mu.M, 85. mu.M, 95. mu.M, 105. mu.M, and placed in a fluorescence spectrophotometer.
(3) Detecting the difference of carbon quantum dots containing amino functionalization under the excitation wavelength of 353nm, wherein the maximum excitation wavelength of carbon quantum dots containing amino functionalization is 353nm, the reaction time is 2minThe fluorescence intensity of the copper ion solution with concentration is I, and the fluorescence intensity of the copper ion solution with concentration of 0 mu M is taken as I0The fluorescence spectrum was obtained as shown in FIG. 1.
(4) The method can be obtained according to the Stern-Volmer equation
Wherein Ksv is the quenching constant, [ Q ]]Indicates the concentration of copper ions. With I0I is the ordinate and the concentration of copper ions is the abscissa, and the graph shown in FIG. 2 is plotted.
(5) As can be seen from the linear fitting results, the linear relation R is very good in the range of 0-45 mu M of copper ion concentration20.987, linear equation I0-I＝10.3[Q]+39.8. The detection limit (3 delta/K) is as low as 0.49 mu M.
(6) Adding 2ml of amino-functionalized carbon quantum dot aqueous solution into a quartz cuvette, adding a solution to be detected with unknown copper ion concentration, detecting fluorescence intensity under the excitation wavelength of 353nm, and substituting the fluorescence intensity into the linear equation obtained in the step 5 to calculate the concentration of copper ions in the object to be detected.
In the embodiment, the carambola juice is used as a raw material to synthesize the amino-functionalized carbon quantum, the synthesis method is simple in step and good in repeatability, the carbon quantum dots are used as fluorescent probes for detecting the concentration of copper ions in water, and compared with other methods for detecting the copper ions, the method has a wider linear range. The method does not need expensive and complicated instruments, and has simple operation and reliable result.
Example 2
(1) Investigation of optimum pH: 200 mu L of carbon quantum dot aqueous solution, 2ml of phosphate buffer solution with different pH values and 10 mu L of 1mM copper ion solution are sequentially added into a quartz cuvette, and then the quartz cuvette is shaken up and balanced for 2min, and fluorescence measurement is carried out by taking 353nm as an excitation wavelength. The influence of the pH value on the fluorescence quenching efficiency is studied by adjusting the pH value of the phosphate buffer solution to 2.0-10.0. As shown in fig. 3, the fluorescence quenching efficiency is preferably in the range of pH 4.0 to 6.0, but the quenching efficiency is maximized at pH 4.0, and the quenching efficiency is rather decreased at pH 6.0, so that pH 4.0 is selected as the optimum pH.
(2) Investigation of optimal reaction time: 2ml of an aqueous solution of carbon quantum dots (pH 4) and 10. mu.L of a 1mM copper ion solution were sequentially added to a quartz cuvette, and then the mixture was shaken to be equilibrated for 0 to 10min, and fluorescence measurement was performed with 353nm as an excitation wavelength. As shown in FIG. 4, the fluorescence quenching efficiency reached a maximum at 2min, and 2min was chosen as the optimal reaction time for the consistency of the experimental process.
Example 3
(1) Interference investigation of common metal ions on copper ion detection: 2ml of an aqueous solution of carbon quantum dots (pH 4) and 1mM of a different metal ion such as Ag+，Co2+，Cr3+，Fe3+，Mg2+，Ni2+，Pb2+，Zn2+，Al3+And Ca2+Sequentially adding into a quartz cuvette, shaking uniformly, balancing for 2min, and performing fluorescence measurement with 353nm as excitation wavelength. As shown in FIG. 5, the interference substances present in the conventional practical samples have little influence on the quantitative determination of copper ions.
FIG. 1 is a fluorescence spectrum of a carbon quantum dot whose fluorescence intensity varies with the concentration of copper ions. The volume of the amino-functionalized carbon quantum dot is 2ml, the concentration is 0.05mg/ml, the fluorescence intensity of the amino-functionalized carbon quantum dot is gradually reduced along with the concentration (0-105 mu M) of copper ions under the maximum excitation wavelength of 353nm, and the change of a fluorescence spectrogram shows that the amino-functionalized carbon quantum dot can realize sensitive detection on trace copper ions.
FIG. 2 is a linear graph showing the fluorescence intensity of carbon quantum dots as a function of the concentration of copper ions. It can be seen that the copper ion concentration is in the range of 0-45 mu M, and the linear relation R is very good20.9867, linear equation I0-I＝10.3[Q]+39.8。
FIG. 3 is a graph showing the effect of different pH values on the fluorescence intensity of a carbon quantum dot-copper ion system. The fluorescence quenching efficiency is preferably in the range of pH 4.0 to 6.0, and the optimum pH is selected to be pH 4.0, because the quenching efficiency is maximized at pH 4.0 and the quenching efficiency is rather decreased at pH 6.0.
FIG. 4 is a graph showing the effect of reaction time on the fluorescence intensity of a carbon quantum dot-copper ion system. The optimum reaction time was chosen to be 2 min.
FIG. 5 is a bar graph showing the specificity for detecting copper ions in the presence of different types of metal ions. From the figure, it is understood that the quantum dots of the amino-functionalized carbon have strong specificity to copper ions and are less interfered by other ions.
Claims (10)
1. The method for preparing the carbon quantum dots by taking carambola as a carbon source is characterized by comprising the following steps of:
mixing and stirring fresh carambola juice and polyethyleneimine, carrying out hydrothermal reaction at 120-180 ℃, filtering with a filter membrane after the reaction is finished, and dialyzing the filtrate to obtain the carbon quantum dots with amino functionalization.
2. The method according to claim 1, wherein the hydrothermal reaction time is 10-12 h.
3. The method of claim 1, wherein the filtration is performed using a 0.22 μm microfiltration membrane.
4. The method of claim 1, wherein the dialysis is performed using a dialysis bag with a molecular weight of 1000Da and a dialysis time of 48 h.
5. A carbon quantum dot produced by the method according to any one of claims 1 to 4.
6. Use of the carbon quantum dot according to claim 5 in copper ion detection.
7. Use according to claim 6, characterized in that it comprises the following steps: adding the copper ion solution to be detected into the aqueous solution of the amino-functionalized carbon quantum dots, detecting the fluorescence intensity after the reaction is balanced, and calculating to obtain the concentration of the copper ions in the copper ion solution to be detected according to the linear relation between the fluorescence intensity and the concentration of the copper ions.
8. The use of claim 7, wherein the concentration of the aqueous solution of the carbon quantum dots is 0.05mg/ml, and the pH of the solution is 4.0-6.0.
9. The use according to claim 7, wherein the reaction time required for equilibration is 2 min.
10. The use according to claim 7, wherein the excitation wavelength for detecting the fluorescence intensity is 353 nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911201883.1A CN112881350A (en) | 2019-11-29 | 2019-11-29 | Preparation method of carbon quantum dots with carambola as carbon source and application of carbon quantum dots in copper ion detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911201883.1A CN112881350A (en) | 2019-11-29 | 2019-11-29 | Preparation method of carbon quantum dots with carambola as carbon source and application of carbon quantum dots in copper ion detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112881350A true CN112881350A (en) | 2021-06-01 |
Family
ID=76038633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911201883.1A Pending CN112881350A (en) | 2019-11-29 | 2019-11-29 | Preparation method of carbon quantum dots with carambola as carbon source and application of carbon quantum dots in copper ion detection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112881350A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113390840A (en) * | 2021-06-12 | 2021-09-14 | 宁德师范学院 | Method for synthesizing carbon dots and detecting copper ions in water body |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105001862A (en) * | 2015-07-30 | 2015-10-28 | 西华师范大学 | Preparation of carbon quantum dots by use of aloe as carbon source and detection method of lemon yellow |
| CN109097032A (en) * | 2018-08-20 | 2018-12-28 | 上海大学 | The preparation method of carbon quantum dot fluorescent material and its application in copper ion detection |
-
2019
- 2019-11-29 CN CN201911201883.1A patent/CN112881350A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105001862A (en) * | 2015-07-30 | 2015-10-28 | 西华师范大学 | Preparation of carbon quantum dots by use of aloe as carbon source and detection method of lemon yellow |
| CN109097032A (en) * | 2018-08-20 | 2018-12-28 | 上海大学 | The preparation method of carbon quantum dot fluorescent material and its application in copper ion detection |
Non-Patent Citations (2)
| Title |
|---|
| MUHAMMAD ZULFAJRI， ET AL: "Nitrogen-Doped Carbon Dots from Averrhoa carambola Fruit Extract as a Fluorescent Probe for Methyl Orange", 《SENSORS》 * |
| 李敏: "生物质基碳量子点的制备修饰及在铜离子检测的应用", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅰ辑》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113390840A (en) * | 2021-06-12 | 2021-09-14 | 宁德师范学院 | Method for synthesizing carbon dots and detecting copper ions in water body |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2020103861A4 (en) | Preparation of chicken feather nitrogen-doped carbon quantum dots based fluorescent probes and paraquat detection method | |
| CN110865061B (en) | Simultaneous detection of nitrite ions and Hg2+Dual emission fluorescent probe and method thereof | |
| CN109342385B (en) | Carbon quantum dot for rapidly detecting nitrite content in food and environment and application method thereof | |
| CN111141711B (en) | Nitrite detection method based on carbon nitride quantum dots | |
| CN110272734B (en) | Preparation method and application of high-quantum-yield carbon quantum dots for NO detection | |
| CN110938430A (en) | Silicon and nitrogen co-doped carbon quantum dot and preparation method and application thereof | |
| CN112326579B (en) | Method for simultaneously detecting nitrite and ascorbic acid in food | |
| CN110018146B (en) | Method for detecting palladium ions based on fluorescent carbon quantum dots | |
| Liu et al. | A two-dimensional zinc (II)-based metal-organic framework for fluorometric determination of ascorbic acid, chloramphenicol and ceftriaxone | |
| CN112881350A (en) | Preparation method of carbon quantum dots with carambola as carbon source and application of carbon quantum dots in copper ion detection | |
| CN113310960B (en) | Sulfur quantum dot synthesis method and sulfur quantum dot-based Fe determination method2+And H2O2Method (2) | |
| CN112251218B (en) | Preparation method of ethylenediamine functionalized carbon quantum dots and application of ethylenediamine functionalized carbon quantum dots in catechol detection | |
| CN115521786B (en) | Red light carbon dot, preparation method thereof and application thereof in brilliant blue detection | |
| CN110408387B (en) | Green fluorescent carbon dots and preparation method and application thereof | |
| CN110204734B (en) | Polyethyleneimine/salicylaldehyde modified cellulose material and preparation method and application thereof | |
| CN117487540A (en) | Microwave-assisted synthesis method and application of nitrogen-iron-manganese co-doped carbon point | |
| CN109053711B (en) | Probe compound for mercury ion detection and preparation method and application thereof | |
| CN112710649B (en) | Method for detecting kanamycin sulfate by using dual-signal-enhanced surface-enhanced Raman spectroscopy | |
| CN115753719A (en) | Construction method of environment-friendly ratiometric fluorescent probe based on blue and red carbon dots and application of environment-friendly ratiometric fluorescent probe to efficient detection of mercury ions | |
| CN114032096A (en) | N-doped carbon dot and preparation method thereof and Cu-doped carbon dot2+Applications in assays | |
| CN114044511A (en) | Preparation method and application of beer-based nitrogen-phosphorus co-doped biomass carbon dots | |
| CN111286325B (en) | Carbon quantum dot emitting yellow fluorescence and preparation method and application thereof | |
| CN113861962A (en) | Ratiometric fluorescent probe, preparation method thereof and application thereof in detection of hydrogen peroxide | |
| CN111234815A (en) | Preparation and use methods of biomass carbon quantum dot fluorescence detector | |
| CN110879223A (en) | Rapid detection reagent and detection method for formaldehyde in beer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210601 |