Fluorescent carbon dot for optical detection and preparation process thereof

Abstract

The invention discloses a fluorescent carbon dot for optical detection and a preparation process thereof. The fluorescent carbon dot comprises the following components in parts by mass: 1-2.5 parts of citric acid; and 5 to 12.5 parts of arginine. The preparation process comprises the following steps: mixing a citric acid raw material and an arginine raw material through deionized water, heating in a reaction kettle, centrifuging, centrifugally washing with ethanol and deionized water, and carrying out vacuum freeze drying to obtain the product. The fluorescent carbon dot is low in preparation cost and high in yield, the obtained product is good in dispersity and high in fluorescence quantum yield, the quality and precision of optical detection are greatly improved, and the fluorescent carbon dot can be used as an optical crystal material such as a luminescent material, an excitation material and a scintillation crystal, has good application value in the fields of biological imaging, ion detection, fluorescence labeling and the like, and has wide application prospects. The preparation process is simple in steps, the yield of the fluorescent carbon dots can be increased, the manufacturing cost can be reduced, and the requirements of industrial production can be met.

Description

Technical Field

[0001] This invention relates to the field of optical detection technology, and in particular to a fluorescent carbon dot for optical detection and its preparation process. Background Technology

[0002] Cutting fluids play a vital role in metalworking, including cooling, lubrication, and cleaning, and are key factors in ensuring machining accuracy and tool life.

[0003] With technological advancements and increasingly stringent environmental requirements, the performance requirements for cutting fluids are constantly rising, especially in terms of environmental protection and health.

[0004] Current cutting fluids generate aerosols during use. These tiny particles pose a threat to human health, such as respiratory illnesses. Furthermore, the diffusion of aerosols can pollute the workshop environment, increasing cleaning and maintenance costs. Current technologies also lack the means to visually label and detect aerosols. Summary of the Invention

[0005] The purpose of this invention is to provide a technical solution for fluorescent carbon dots used in optical detection and their preparation process, addressing the shortcomings of existing technologies. Fluorescent carbon dots not only have low preparation cost and high yield, but also exhibit good product dispersion and high fluorescence quantum yield, greatly improving the quality and accuracy of optical detection. They can be used as optical crystal materials such as luminescent materials, excitation materials, and scintillation crystals, and have good application value in fields such as bioimaging, ion detection, and fluorescent labeling. The preparation process is simple, which not only increases the yield of fluorescent carbon dots and reduces manufacturing costs, but also meets the requirements of industrial production.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A fluorescent carbon dot for optical detection, characterized by comprising the following parts by weight: Citric acid 1-2.5 parts; Arginine 5-12.5 parts.

[0007] This fluorescent carbon dot not only has low preparation cost and high yield, but also produces products with good dispersion and high fluorescence quantum yield, which greatly improves the quality and accuracy of optical detection. It can be used as an optical crystal material such as a luminescent material, excitation material, and scintillation crystal, and has good application value in fields such as biological imaging, ion detection, and fluorescent labeling.

[0008] The above-described process for preparing fluorescent carbon dots for optical detection is characterized by comprising the following steps: (a) Weigh the citric acid raw material and arginine raw material using a balance, and mix them thoroughly in deionized water to obtain solution A; (b) Place solution A into a reaction vessel, place the reaction vessel in a drying oven and heat it to obtain solution B; (c) Transfer solution B to a centrifuge and obtain precipitate C by centrifugation; (d) The precipitate C was washed by centrifugation with ethanol and deionized water respectively, and then freeze-dried under vacuum to obtain the final product.

[0009] The preparation process is simple and can not only increase the yield of fluorescent carbon dots and reduce manufacturing costs, but also meet the requirements of industrial production.

[0010] Furthermore, in step (a), the amount of citric acid is 1–5 mol and the amount of arginine is 5–25 mol.

[0011] Furthermore, the temperature of the drying oven in step (b) is 150℃~400℃, and the heating time is 2~8h.

[0012] Furthermore, the reactor in step (b) is a hydrothermal reactor.

[0013] Furthermore, in step (c), the centrifugation rate of the centrifuge is 1000–20000 r / min, and the centrifugation time is 10–30 min.

[0014] Furthermore, the vacuum freezing temperature in step (d) is -80 to -20°C, and the drying time is 1 to 4 hours.

[0015] The present invention, by adopting the above-described technical solution, has the following beneficial effects: The fluorescent carbon dots of this invention not only have low preparation cost and high yield, but also have good product dispersion and high fluorescence quantum yield, which greatly improves the quality and accuracy of optical detection. They can be used as optical crystal materials such as luminescent materials, excitation materials, and scintillation crystals, and have good application value in fields such as biological imaging, ion detection, and fluorescent labeling. The preparation process is simple, which can not only increase the yield of fluorescent carbon dots and reduce manufacturing costs, but also meet the requirements of industrial production. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a TEM image of a fluorescent carbon dot for optical detection and its preparation process, according to the present invention. Figure 2 This is the FTIR image of the fluorescent carbon dots in this invention; Figure 3 This is a photoluminescence diagram of fluorescent carbon dots added to the cutting fluid in this invention; Figure 4 This is a friction and wear diagram illustrating the effect of fluorescent carbon dots on cutting fluid lubrication in this invention; Figure 5 This is a process flow diagram for the preparation of fluorescent carbon dots in this invention. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0020] like Figures 1 to 4 As shown, a fluorescent carbon dot for optical detection according to the present invention comprises the following parts by weight: Citric acid 1-2.5 parts; Arginine 5-12.5 parts.

[0021] This fluorescent carbon dot not only has low preparation cost and high yield, but also produces products with good dispersion and high fluorescence quantum yield, which greatly improves the quality and accuracy of optical detection. It can be used as an optical crystal material such as a luminescent material, excitation material, and scintillation crystal, and has good application value in fields such as biological imaging, ion detection, and fluorescent labeling.

[0022] like Figure 5 The diagram illustrates a process for preparing fluorescent carbon dots for optical detection according to the present invention, comprising the following steps: (a) Weigh the citric acid raw material and arginine raw material using a balance, mix them thoroughly in deionized water to obtain a transparent solution A; the amount of citric acid is 1-5 mol and the amount of arginine is 5-25 mol.

[0023] (b) Place the transparent solution A into the reaction vessel, and heat the reaction vessel in a drying oven to obtain a yellow-green solution B; the temperature of the drying oven is 150℃~400℃, and the heating time is 2~8h. The reaction vessel is a hydrothermal reaction vessel.

[0024] (c) Transfer the yellow-green solution B to a centrifuge and obtain a green precipitate C by centrifugation; the centrifugation rate of the centrifuge is 1000-20000 r / min and the centrifugation time is 10-30 min.

[0025] (d) The green precipitate C was washed by centrifugation with ethanol and deionized water, respectively, and then freeze-dried under vacuum to obtain the final product. The vacuum freezing temperature was -80 to -20°C, and the drying time was 1 to 4 hours.

[0026] The preparation process is simple and can not only increase the yield of fluorescent carbon dots and reduce manufacturing costs, but also meet the requirements of industrial production.

[0027] Example 1 Weigh 0.1921 g of citric acid, and weigh another 0.871 g. Pour the citric acid and arginine into a beaker, add 15 ml of deionized water, and stir at 800 rpm until the two mixtures are fully dissolved. A clear solution A is obtained. Solution A is added to a hydrothermal reactor and heated at 200°C for 4 hours. After cooling to room temperature, a clear yellow-green solution B is obtained. Solution B is centrifuged at 8000 rpm for 15 minutes. A green precipitate C precipitates from solution B. The precipitate is washed away with ethanol. The precipitate is then dried in a freeze dryer for 0.5–1 hour to obtain 1.1 g of viscous substance D. The mass of viscous substance D is bright blue under 365 nm ultraviolet light.

[0028] Example 2 Weigh 0.200g of citric acid and 0.600g of arginine. Pour the citric acid and arginine into a beaker, add 20ml of deionized water, and mix thoroughly with a stirring speed of 10000r / min to obtain a transparent solution A. Pour solution A into a hydrothermal reactor and heat at 180℃ for 6 hours, then allow it to cool at room temperature to obtain a transparent pale yellow solution B. Place solution B in a centrifuge and centrifuge at 10000r / min for 12 minutes. A pale yellow precipitate C precipitates out of solution B. Wash precipitate C alternately with deionized water and ethanol. After the washings become clear, the precipitate is obtained. Place precipitate C in a vacuum drying oven and dry for 1 hour to obtain 1.2g of viscous substance D. Viscous substance D exhibits a bright blue light under ultraviolet light.

[0029] Example 3 Weigh 0.300g of citric acid and 0.750g of arginine. Add both to a beaker, add 30ml of deionized water, and stir until completely dissolved to obtain a clear solution A. Add solution A to a hydrothermal reactor and heat at 200℃ for 5 hours. After cooling to room temperature, remove the solution to obtain a clear, dark green solution B. Centrifuge solution B at 11000r / min for 10 minutes to precipitate a dark green precipitate C. Wash precipitate C repeatedly with deionized water and ethanol to obtain a pure precipitate. Dry precipitate C in a freeze dryer for 1 hour to obtain 1.4g of viscous substance D. Viscous substance D exhibits a bright blue light under ultraviolet light.

[0030] Example 4 Weigh 0.300 g of citric acid and 0.800 g of arginine. Add 25 ml of deionized water and stir until completely dissolved to obtain a clear solution A. Add solution A to a hydrothermal reactor and heat at 190°C for 6 hours. After cooling to room temperature, remove the solution to obtain a clear, pale yellow solution B. Place solution B in a centrifuge and centrifuge at 10,000 r / min for 15 minutes to precipitate a pale yellow precipitate C. Wash precipitate C with ethanol and vacuum dry for 1 hour to obtain 1.3 g of viscous substance D. Viscous substance D shows a bright blue light under ultraviolet light.

[0031] Example 5 Weigh 0.400g of citric acid and 1.000g of arginine. Add 25ml of deionized water and stir until completely dissolved to obtain solution A. Pour solution A into a hydrothermal reactor and heat at 210℃ for 4 hours. After cooling to room temperature, remove the reactor to obtain a transparent, deep yellow solution B. Transfer solution B to a centrifuge tube and centrifuge at 10000r / min for 10 minutes to precipitate a deep yellow precipitate C. Wash the precipitate with ethanol, and finally freeze-dry precipitate C to obtain 1.6g of viscous substance D. Viscous substance D exhibits a bright blue light under ultraviolet light.

[0032] Example 6 Weigh 0.500g of citric acid and 1.200g of arginine, add 18ml of deionized water, and stir until dissolved to obtain solution A. Add solution A to a hydrothermal reactor and heat at 250℃ for 3 hours. After cooling to room temperature, a transparent yellow solution B is obtained. Transfer solution B to a centrifuge and centrifuge at 12000r / min for 12 minutes to precipitate a yellow precipitate C. Wash precipitate C repeatedly with ethanol and deionized water to obtain pure precipitate C. Place precipitate C in a freeze dryer and dry for 1 hour to obtain 1.8g of viscous substance D. Viscous substance D exhibits a bright blue light under a 365nm UV lamp.

[0033] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to achieve substantially the same technical effect are all covered within the protection scope of the present invention.

Claims

1. A fluorescent carbon dot for optical detection, characterized in that... Includes the following parts by weight: Citric acid 1-2.5 parts; Arginine 5-12.5 parts.

2. The preparation process of fluorescent carbon dots for optical detection as described in claim 1, characterized in that... Includes the following steps: (a) Weigh the citric acid raw material and arginine raw material using a balance, and mix them thoroughly in deionized water to obtain solution A; (b) Place solution A into a reaction vessel, place the reaction vessel in a drying oven and heat it to obtain solution B; (c) Transfer solution B to a centrifuge and obtain precipitate C by centrifugation; (d) The precipitate C was washed by centrifugation with ethanol and deionized water respectively, and then freeze-dried under vacuum to obtain the final product.

3. The preparation process of fluorescent carbon dots for optical detection according to claim 2, characterized in that: The citric acid in step (a) is 1 to 5 mol, and the arginine is 5 to 25 mol.

4. The preparation process of fluorescent carbon dots for optical detection according to claim 2, characterized in that: The temperature of the drying oven in step (b) is 150℃~400℃, and the heating time is 2~8h.

5. The preparation process of fluorescent carbon dots for optical detection according to claim 2, characterized in that: The reactor in step (b) is a hydrothermal reactor.

6. The preparation process of fluorescent carbon dots for optical detection according to claim 2, characterized in that: The centrifuge in step (c) has a centrifugation rate of 1000-20000 r / min and a centrifugation time of 10-30 min.

7. The preparation process of fluorescent carbon dots for optical detection according to claim 2, characterized in that: The vacuum freezing temperature in step (d) is -80 to -20°C, and the drying time is 1 to 4 hours.

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