Application of fluorescently labeled carbon quantum dots from waste banana peel in preparation of cancer cell imaging agent

Abstract

The application discloses application of fluorescently labeled carbon quantum dots prepared from waste banana peels to preparation of cancer cell imaging agents and belongs to the technical field of polymer cell imaging. The preparation of the fluorescently labeled carbon quantum dots realizes reuse of the waste banana peels. The fluorescently labeled carbon quantum dots prepared from the waste banana peels are verified by experiments to have extremely stable fluorescence signals, can remain unchanged within 30 days, have good stability and obvious fluorescence labeling imaging performance. The particle size distribution is uniform, the size is small, the average particle size is 7.59 nm, the fluorescently labeled carbon quantum dots are easy to enter cells, and good potential is provided for cell imaging. The surface functional groups are rich, the fluorescently labeled carbon quantum dots are easy to modify or modify, and the fluorescently labeled carbon quantum dots provide possibility for application in other fields.

Description

Technical Field

[0001] This invention belongs to the field of cell imaging technology, specifically relating to the application of fluorescently labeled carbon quantum dots from discarded banana peels in the preparation of cancer cell imaging agents. Background Technology

[0002] Nanomaterials possess physical and chemical properties distinct from conventional materials, such as surface effects, quantum size effects, small size effects, and quantum tunneling effects. These superior properties can provide better services for people's lives and production. Carbon is one of the most abundant elements in nature and one of the most important building blocks of living organisms. The basic structural units of living organisms, such as amino acids and nucleotides, are composed of carbon. Therefore, carbon materials are generally non-toxic or low-toxic to living organisms. Nanomaterials can be used as adsorbents, high-flow membranes, depth filters, antibacterial agents, environmental sensors, and pollution prevention materials. In biology, carbon nanotubes can be used for antibody recognition, nucleic acid sequence recognition, bioseparation, and biocatalysis. Fluorescent carbon dots, as a novel zero-dimensional nanomaterial, are composed of dispersed, spherical nanoparticles with a size of less than 10 nm. Its small particle size allows it to easily enter cells through endocytosis and osmosis, which is beneficial for bioimaging. Its excitation spectrum is broad and continuous, and its emission spectrum can be "coordinated." Through appropriate doping and chemical treatment, or by combining with nanomaterials, it can be used in optoelectronic materials, contrast agents for magnetic resonance imaging, and magnetic data storage applications for battery electrodes. The carbon dot surface contains many carboxylic acid groups, thus endowing it with good water solubility and suitability for combining with various organic, polymer, inorganic, and biomass substances and exhibiting subsequent functionalization properties. It has excellent resistance to photobleaching, which is beneficial for the application of carbon dots as fluorescent probes in cell tracking, imaging, and other fields. The most attractive feature is the low biotoxicity and good biocompatibility of carbon dots, which can replace some of the toxic and environmentally polluting heavy metal quantum dot fluorescent materials that are currently widely used.

[0003] For cancer cell imaging, semiconductor quantum dots are commonly used in the market because they have the advantage of high luminescence efficiency, but they have significant toxic side effects. Organic dye molecules are also commonly used in the market or in laboratories, but they are generally expensive and have poor resistance to photobleaching and poor stability. Summary of the Invention

[0004] The primary objective of this invention is to provide fluorescently labeled carbon quantum dots from waste banana peels. The preparation of these fluorescently labeled carbon quantum dots enables the reuse of waste banana peels, turning waste into treasure. Furthermore, experiments have verified that the fluorescently labeled carbon quantum dots prepared from waste banana peels exhibit extremely stable fluorescence signals, remaining unchanged for 30 days, demonstrating excellent stability and clear fluorescent labeling imaging properties.

[0005] The second objective of this invention is to provide a method for preparing fluorescently labeled carbon quantum dots from waste banana peels. The fluorescently labeled carbon quantum dots from waste banana peels prepared by this method have the advantages of simple synthesis, low toxicity and side effects, small particle size, and non-uniform size distribution.

[0006] This invention is achieved through the following technical solution:

[0007] Application of fluorescently labeled carbon quantum dots from discarded banana peels in the preparation of cancer cell imaging agents.

[0008] Preferably, the cancer cells are HepG2 cancer cells and HeLa cancer cells.

[0009] A method for preparing fluorescently labeled carbon quantum dots from waste banana peels, comprising the following steps:

[0010] Waste, unrotten banana peels were selected, cleaned, and the inner pulp was removed. The peels were then cut into sections and dried in an oven. Fluorescently labeled carbon quantum dots were prepared from the waste banana peels using a hydrothermal method.

[0011] Preferably, each segment is 2-3 cm long.

[0012] Preferably, the drying process involves a drying temperature of 60–65°C and a drying time of 12–24 hours.

[0013] Preferably, the hydrothermal treatment process includes: placing the dried waste banana peels in a 160-240°C environment for 3-24 hours.

[0014] Preferably, the particle size of the fluorescently labeled carbon quantum dots on the waste banana peel is 5-9 nm, and more preferably 7.59 nm.

[0015] A fluorescently labeled carbon quantum dot made from waste banana peel is obtained by the preparation method described above.

[0016] A fluorescent labeling material made from waste banana peels is prepared by fluorescent labeling carbon quantum dots on the waste banana peels.

[0017] Application of a fluorescent labeling material from discarded banana peels in the preparation of cancer cell imaging agents.

[0018] Compared with the prior art, the present invention has at least the following technical effects:

[0019] (I) This invention provides fluorescently labeled carbon quantum dots from waste banana peels, enabling the reuse of waste banana peels and turning waste into treasure. Furthermore, experiments have verified that the fluorescently labeled carbon quantum dots prepared from waste banana peels exhibit extremely stable fluorescence signals, remaining unchanged for 30 days, demonstrating good stability and clear fluorescent labeling imaging properties.

[0020] (ii) In this preparation method:

[0021] (1) It uses discarded banana peels, which not only provides abundant raw materials, but also makes full use of discarded banana peels;

[0022] (2) The fluorescently labeled carbon quantum dots from the discarded banana peels have a uniform particle size distribution of 5–9 nm, a small size with an average particle size of 7.59 nm, and are easy to enter cells, providing good potential for cell imaging. They are also rich in surface functional groups, making them easy to modify or alter, thus offering possibilities for applications in other fields. Attached Figure Description

[0023] Figure 1 Electron microscope image and particle size distribution of fluorescently labeled carbon quantum dots obtained from waste banana peels;

[0024] Figure 2 This is a schematic diagram of XPS characterization of carbon dot structure;

[0025] Figure 3 A schematic diagram illustrating fluorescence intensity testing at fixed times each day for 30 days of storage;

[0026] Figure 4 This is a schematic diagram of the ultraviolet-visible absorption spectrum, excitation spectrum, and emission spectrum.

[0027] Figure 5 A schematic diagram of fluorescence imaging of fluorescently labeled carbon quantum dots on discarded banana peels in HepG2 cancer cells;

[0028] Figure 6 A schematic diagram of fluorescence imaging of fluorescently labeled carbon quantum dots on discarded banana peels in HeLa cancer cells. Detailed Implementation

[0029] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] One specific embodiment of the present invention is as follows:

[0031] Application of fluorescently labeled carbon quantum dots from discarded banana peels in the preparation of cancer cell imaging agents.

[0032] Preferably, the cancer cells are HepG2 cancer cells and HeLa cancer cells.

[0033] A method for preparing fluorescently labeled carbon quantum dots from waste banana peels, comprising the following steps:

[0034] Waste, unrotten banana peels were selected, cleaned, and the inner pulp was removed. The peels were then cut into sections and dried in an oven. Fluorescently labeled carbon quantum dots were prepared from the waste banana peels using a hydrothermal method.

[0035] Preferably, each segment is 2-3 cm long.

[0036] Preferably, the drying process involves a drying temperature of 60–65°C and a drying time of 12–24 hours.

[0037] Preferably, the hydrothermal treatment process includes: placing the dried waste banana peels in a 160-240°C environment for 3-24 hours.

[0038] A fluorescently labeled carbon quantum dot made from waste banana peel is obtained by the preparation method described above.

[0039] A fluorescent labeling material made from waste banana peels is prepared by fluorescent labeling carbon quantum dots on the waste banana peels.

[0040] Application of a fluorescent labeling material from discarded banana peels in the preparation of cancer cell imaging agents.

[0041] Experiment 1: Fluorescent labeling of carbon quantum dots on discarded banana peels

[0042] A method for preparing fluorescently labeled carbon quantum dots from waste banana peels, comprising the following steps:

[0043] Waste, unrotten banana peels were selected, cleaned, and the inner pulp was removed. The peels were then cut into sections and dried in an oven. Fluorescently labeled carbon quantum dots were prepared from the waste banana peels using a hydrothermal method.

[0044] When cutting, each segment should be 2-3 cm long.

[0045] During the drying process, the drying temperature is 60°C and the drying time is 24 hours.

[0046] The hydrothermal treatment process includes: placing the dried waste banana peels in a 240°C environment for 5 hours.

[0047] like Figure 1 The image shows an electron microscope image and particle size distribution diagram of fluorescently labeled carbon quantum dots from waste banana peels prepared as described above.

[0048] (a) is a schematic diagram of a transmission electron microscope with a scale bar of 200 nm; the upper left corner of Figure a is a schematic diagram of a high-resolution transmission electron microscope; (b) is a schematic diagram of particle size distribution.

[0049] like Figure 1 The results show that Figure (a) indicates that the prepared nanoparticles are smaller than 10 nm. Figure (b) shows that the average particle size is 7.59 nm according to the particle size statistics of Figure (a). Combined with the XPS results in Experiment 2, the C element content is 66.08%, which confirms that the nanoparticles are carbon quantum dots, that is, carbon dots.

[0050] (a) The upper corner inset is further magnified, showing a lattice stripe structure with 0.21 nm, corresponding to the 100 crystal plane of graphite, indicating that the carbon dot has a graphitized structure, that is, a graphitized carbon dot.

[0051] Experiment 2: Characterization of the structure of fluorescently labeled carbon quantum dots on discarded banana peels using XPS

[0052] like Figure 2 The figure shown is a schematic diagram of XPS characterization of carbon dot structure.

[0053] Figure (a) shows that the contents of C, O and N elements are 66.08%, 28.00% and 5.92% respectively, indicating that the proportion of C element in the obtained nanoparticles is very high, further confirming that they belong to carbon quantum dots (abbreviated as carbon dots). Figures (b), (c) and (d) respectively show the peak fitting of functional groups containing C, O and N elements.

[0054] Figure 2 The results (a), (b), (c), and (d) show that the carbon dots have abundant functional groups (shown in the upper right corner of the figure). The abundance of functional groups on the surface of the fluorescently labeled carbon quantum dots from discarded banana peels means that they are easy to modify and can meet the needs of different applications.

[0055] Experiment 3: Fluorescence signal detection

[0056] like Figure 3 The diagram shows a fluorescence intensity test conducted at a fixed time each day during the 30-day storage period.

[0057] The results showed that the fluorescently labeled carbon quantum dots from the discarded banana peel exhibited almost constant fluorescence intensity over 30 days, demonstrating good stability.

[0058] Experiment 4: Ultraviolet-Visible Absorption Detection, Excitation Spectroscopy, and Emission Spectroscopy Detection under Different Wavelength Light Sources

[0059] like Figure 4 The diagram shows the UV-Vis absorption, excitation, and emission spectra. The lower right corner of the diagram shows the brownish-yellow color of the carbon dot solution under natural light.

[0060] The results showed that the fluorescently labeled carbon quantum dots from discarded banana peels possessed UV-Vis absorption capabilities, with particularly strong absorption in the violet region. The emission spectrum revealed tunable fluorescence emission; the fluorescence emission peak red-shifted with increasing excitation wavelength. The optimal excitation wavelength (red line) was observed to be around 350 nm.

[0061] Experiment 5: Application of fluorescently labeled carbon quantum dots from discarded banana peels in fluorescence imaging of HepG2 cancer cells

[0062] like Figure 5 The image shown is a schematic diagram of fluorescence imaging of fluorescently labeled carbon quantum dots from discarded banana peels in HepG2 cancer cells. From left to right, the images are: bright-field image, dark-field image, and a combination of bright-field and dark-field images.

[0063] First, HepG2 cells containing carbon dots were cultured: HepG2 cells were cultured for 48 hours with DMEM + 10% FBS + 1% PS as the nutrient solution and carbon dot nutrient solution of 1 mg / mL.

[0064] Then, an image was captured using a laser confocal microscope, and signals were collected in the 450-650nm channel range.

[0065] like Figure 5 The results showed that the carbon dots could be imaged in HepG2 cells with bright signals, indicating that the carbon dots are a good HepG2 cell display agent.

[0066] Experiment 6: Application of fluorescently labeled carbon quantum dots from discarded banana peels in fluorescence imaging of HeLa cancer cells

[0067] like Figure 6 The image shown is a schematic diagram of fluorescence imaging of fluorescently labeled carbon quantum dots from discarded banana peels in HeLa cancer cells. From left to right, the images are: bright-field image, dark-field image, and a combination of bright-field and dark-field images.

[0068] First, HeLa cells containing carbon dots were cultured: HeLa cells were cultured for 48 hours with DMEM + 10% FBS + 1% PS as the nutrient solution and 1 mg / mL of carbon dot nutrient solution.

[0069] Then, an image was captured using a laser confocal microscope, and signals were collected in the 450-650nm channel range.

[0070] like Figure 6 The results showed that the carbon dots could be imaged in HeLa cells with bright signals, indicating that the carbon dots are a good HeLa cell display agent.

[0071] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The application of fluorescently labeled carbon quantum dots from discarded banana peels in the preparation of cancer cell imaging agents, characterized in that, The cancer cells were HepG2 cancer cells and HeLa cancer cells; The method for preparing fluorescently labeled carbon quantum dots from waste banana peels includes the following steps: Waste, unrotten banana peels were selected, cleaned, and the inner pulp was removed. The peels were then cut into sections and dried in an oven. Fluorescently labeled carbon quantum dots were prepared from the waste banana peels using a hydrothermal method. During the drying process, the drying temperature is 60~65℃; Drying time is 12-24 hours; The hydrothermal treatment process includes: placing the dried waste banana peels in a 160~240℃ environment for 3~24 hours.

2. The application according to claim 1, characterized in that, When cutting, each segment should be 2-3 cm long.

3. The application according to claim 1, characterized in that, The particle size of the fluorescently labeled carbon quantum dots on the waste banana peels is 5~9nm.

4. The application according to claim 3, characterized in that, The particle size of the fluorescently labeled carbon quantum dots on the waste banana peels is 7.59 nm.

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