Water-soluble blue-red dual-emission fluorescent silicon quantum dots, preparation method and application thereof

Abstract

The application discloses water-soluble blue-red dual-emission fluorescent silicon quantum dots, a preparation method and application thereof, and belongs to the field of chemistry and nanometer material science and technology. Gamma-glycidyl ether oxygen propyl trimethoxysilane and nile blue are used as reaction precursors, a hydrothermal reaction is carried out, and then, after purification and drying, water-soluble blue-red dual-emission fluorescent silicon quantum dots are obtained. The one-step hydrothermal synthesis method is used to synthesize water-soluble blue-red dual-emission fluorescent silicon quantum dots with blue light (470 nm) and red light (660 nm) dual emission. The preparation process is simple, the cost is low, no heavy metal elements are contained, the light stability is good, the emission wavelength is long, and the water-soluble blue-red dual-emission fluorescent silicon quantum dots show a good application prospect in the fields of biochemical analysis, cell imaging and anti-counterfeiting.

Description

Technical Field

[0001] This invention relates to the fields of chemistry and nanomaterials science and technology, specifically to water-soluble blue-red dual-emission fluorescent silicon quantum dots, their preparation methods, and applications. Background Technology

[0002] Silicon quantum dots possess excellent optical properties, good biocompatibility, and chemical stability, showing broad application prospects in fields such as biochemical analysis, fluorescence imaging, information anti-counterfeiting, and optoelectronic devices. Compared with conventional semiconductor quantum dots, silicon quantum dots have lower biotoxicity because they do not contain heavy metal elements. Various methods exist for preparing silicon quantum dots, among which hydrothermal synthesis is the most widely used due to its simplicity and low cost. Researchers can prepare silicon quantum dots with different optical properties by controlling the synthesis method, reaction conditions, and raw material ratios.

[0003] Most silicon quantum dots reported in the literature are single-emission fluorescent nanomaterials, with blue and green fluorescence being the most common. Compared to blue-green materials, red fluorescent nanomaterials have significant advantages such as strong resistance to biological matrix interference, greater tissue penetration depth, and lower background interference. Furthermore, although a few silicon quantum dots exhibit dual-emission characteristics, their emission region is still limited to the blue-green light region, with short emission wavelengths and severe spectral overlap between the two emission peaks, resulting in low resolution.

[0004] Therefore, developing long-wavelength, high-spectral-resolution dual-emission silicon quantum dots has significant application value.

[0005] Based on this, the present invention designs water-soluble blue-red dual-emission fluorescent silicon quantum dots, their preparation method and applications to solve the above problems. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides a water-soluble blue-red dual-emission fluorescent silicon quantum dot that is easy to synthesize, has a long emission wavelength, and high dual-peak resolution, along with its preparation method and applications. The aim is to solve the technical problems of single emission peak, short emission wavelength, and difficulty in distinguishing dual emission peaks.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots involves using γ-glycidyl etheroxypropyltrimethoxysilane and Nile blue as reaction precursors, carrying out a hydrothermal reaction, and then purifying and drying to obtain water-soluble blue-red dual-emission fluorescent silicon quantum dots. Furthermore, the hydrothermal reaction temperature is 120℃-200℃, and the reaction time is 2h-20h.

[0008] Furthermore, the molar ratio of Nile Blue and γ-glycidoxypropyltrimethoxysilane is 1:(332-1991).

[0009] Furthermore, the purification method is dialysis.

[0010] Furthermore, the drying method is freeze-drying or oven drying.

[0011] To better achieve the objectives of this invention, this invention also provides a water-soluble blue-red dual-emission fluorescent silicon quantum dot prepared according to the method described.

[0012] To better achieve the objectives of this invention, the present invention also provides the application of water-soluble blue-red dual-emission fluorescent silicon quantum dots in the fields of biochemical analysis, cell imaging, and anti-counterfeiting.

[0013] Furthermore, the water-soluble blue-red dual-emission fluorescent silicon quantum dots can be used as dual-signal fluorescent probes for biochemical analysis and / or cell imaging.

[0014] For example, dual-emission silicon quantum dots are co-incubated with the enzymatic hydrolysis solution of biological enzymes, and the activity of biological enzymes is quantified using a fluorescence spectrometer.

[0015] Furthermore, fluorescent inks are prepared using the water-soluble blue-red dual-emission fluorescent silicon quantum dots for use in the field of anti-counterfeiting.

[0016] Compared with the prior art, the beneficial effects of this invention are as follows: 1. This invention uses a one-step hydrothermal synthesis method to synthesize water-soluble blue-red dual-emission fluorescent silicon quantum dots with both blue light (470 nm) and red light (660 nm) emission, which is simple and low in cost.

[0017] 2. The water-soluble blue-red dual-emission fluorescent silicon quantum dots of the present invention do not contain heavy metal elements and have good environmental and biocompatibility.

[0018] 3. The water-soluble blue-red dual-emission fluorescent silicon quantum dots of the present invention exhibit high-resolution dual emission peak characteristics in the blue light (470 nm) region and the red light (660 nm) region, and have good photostability and long emission wavelength. They can be used to achieve ratio detection and imaging with a single material, effectively reducing the autofluorescence interference of the matrix.

[0019] 4. The silicon quantum dots of the present invention can not only be used as dual-signal fluorescent probes in the fields of biochemical analysis and / or cell imaging, but also as fluorescent inks in the field of anti-counterfeiting. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention is shown. Figure 2 This is a three-dimensional fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention; Figure 3 This is a CIE (International Commission on Illumination) coordinate graph of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention; Figure 4 These are photographs of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention under different excitation wavelengths; Figure 5 The X-ray photoelectron spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention is shown below. Figure 6 This is a TEM (transmission electron microscopy) characterization image of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention; Figure 7 The fluorescence intensity (F) of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention under excitation wavelengths of 360 nm and 560 nm and pH values ​​from 5 to 9 is shown in the figure. 470 / F 660 Ratio line graph; Figure 8 The photostability diagram of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 1 of the present invention is shown. Figure 9 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 2 of this invention is shown. Figure 10 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 3 of this invention is shown. Figure 11 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 4 of this invention is shown. Figure 12 This is the CIE coordinate diagram of the water-soluble blue-red dual-emission fluorescent silicon quantum dots of Example 4 of the present invention; Figure 13 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 5 of this invention is shown. Figure 14The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 6 of this invention is shown. Figure 15 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 7 of this invention is shown. Figure 16 The fluorescence spectrum of the water-soluble blue-red dual-emission fluorescent silicon quantum dots in Example 8 of this invention is shown. Figure 17 This is a fluorescence intensity ratio diagram of water-soluble blue-red dual-emission fluorescent silicon quantum dots used for ratio detection of β-galactosidase activity in Example 1 of the present invention. Figure 18 This is a schematic diagram illustrating the application of water-soluble blue-red dual-emission fluorescent silicon quantum dots in fluorescent ink, as shown in Example 2 of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] Example 1: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 30 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:332, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 140°C for 6 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0024] See Figure 1 As shown in the figure, the two emission peaks of the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 1 are located in the blue light (470 nm) and red light (660 nm) regions. Within the excitation wavelength range of 320-600 nm, the blue light emission peak exhibits excitation dependence, while the red light emission peak shows almost no excitation dependence. Within the excitation wavelength range of 320-420 nm, two fluorescence signals can be detected using the same excitation light. Furthermore, the fluorescence intensity of the blue light emission peak is higher at an excitation wavelength of 340 nm, and the fluorescence intensity of the red light emission peak is higher at an excitation wavelength of 580 nm, which facilitates dual-channel detection.

[0025] See Figure 2 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots exhibit two well-resolved emission centers.

[0026] See Figure 3 As can be seen from the figure, the CIE emission coordinates are (0.16, 0.19) and (0.69, 0.30), indicating that the emitted light from the two peaks is blue light and red light, respectively, and the emitted light has high color purity and no obvious impurities.

[0027] See Figure 4 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots exhibit a gradient fluorescence color from blue-violet to red as the excitation wavelength changes, which provides feasibility for visualization applications.

[0028] See Figure 5 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots are composed of four elements: carbon (52.64%), oxygen (32.42%), nitrogen (1.27%), and silicon (13.67%).

[0029] See Figure 6 As can be seen from the figure, the average particle size of the water-soluble blue-red dual-emission silicon quantum dots is approximately 3.31 nm.

[0030] See Figure 7 As can be seen from the figure, the fluorescence intensity ratio changes little with increasing pH, indicating that the water-soluble blue-red dual-emission silicon quantum dots have good acid and alkali resistance.

[0031] See Figure 8 As can be seen from the figure, the fluorescence intensity ratio of the water-soluble blue-red dual-emission silicon quantum dots changed little within 150 min of continuous irradiation, indicating that the fluorescent material has good photostability.

[0032] Example 2: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 20 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:498, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 160°C for 8 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and freeze-dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0033] See Figure 9As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 2 have two emission peaks with good resolution, located in the blue light (470 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 340 nm and 580 nm, respectively.

[0034] The CIE emission coordinates under 340 nm excitation are (0.15, 0.16), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.30), indicating that the two emission peaks are blue light emission and red light emission, respectively.

[0035] Example 3: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 20 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:498, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 160°C for 6 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0036] See Figure 10 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 3 have two emission peaks with good resolution, located in the blue light (470 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 340 nm and 580 nm, respectively.

[0037] The CIE emission coordinates under 340 nm excitation are (0.16, 0.15), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.29), indicating that the two emission peaks are blue light emission and red light emission, respectively.

[0038] Example 4: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 5 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:1991, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 140°C for 6 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0039] See Figure 11 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 4 have two emission peaks with good resolution, located in the blue light (420 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 360 ​​nm and 580 nm, respectively.

[0040] See Figure 12 As can be seen from the figure, the CIE emission coordinates under 360 nm excitation are (0.18, 0.12), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.30), indicating that the two emission peaks are blue light and red light emission, respectively.

[0041] Example 5: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 20 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:498, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 140°C for 2 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0042] See Figure 13 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 5 have two emission peaks with good resolution, located in the blue light (420 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 360 ​​nm and 580 nm, respectively.

[0043] The CIE emission coordinates under 360 nm excitation are (0.17, 0.13), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.30), indicating that the two emission peaks are blue light emission and red light emission, respectively.

[0044] Example 6: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 20 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:498, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 140°C for 20 h. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0045] See Figure 14 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 6 have two emission peaks with good resolution, located in the blue light (420 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 360 ​​nm and 580 nm, respectively.

[0046] The CIE emission coordinates under 360 nm excitation are (0.17, 0.13), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.30), indicating that the two emission peaks are blue light emission and red light emission, respectively.

[0047] Example 7: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 20 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:498, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 120°C for 6 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0048] See Figure 15As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 7 have two emission peaks with good resolution, located in the blue light (470 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 340 nm and 580 nm, respectively.

[0049] The CIE emission coordinates under 340 nm excitation are (0.16, 0.15), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.30), indicating that the two emission peaks are blue light emission and red light emission, respectively.

[0050] Example 8: This example provides a method for preparing water-soluble blue-red dual-emission fluorescent silicon quantum dots, comprising the following steps: First, weigh 20 mg of Nile Blue and 3 mL of γ-glycidoxypropyltrimethoxysilane at a molar ratio of 1:498, dissolve them in 7 mL of deionized water, and mix thoroughly. Then, transfer the resulting mixture to a polytetrafluoroethylene-lined stainless steel high-pressure reactor and heat at 200°C for 6 hours. After the high-pressure reactor cools naturally to room temperature, crude silicon quantum dot product is obtained. Dialyze the obtained crude silicon quantum dot product using a dialysis membrane with a molecular weight cutoff of 1000 Da, and then centrifuge and dry to obtain water-soluble blue-red dual-emission silicon quantum dots.

[0051] See Figure 16 As can be seen from the figure, the water-soluble blue-red dual-emission silicon quantum dots prepared in Example 8 have two emission peaks with good resolution, located in the blue light (420 nm) region and the red light (660 nm) region, respectively. The former exhibits excitation dependence, while the latter shows almost no excitation dependence. The maximum excitation wavelengths of the two emission peaks are 340 nm and 580 nm, respectively.

[0052] The CIE emission coordinates under 340 nm excitation are (0.19, 0.16), and the CIE emission coordinates under 580 nm excitation are (0.70, 0.30), indicating that the two emission peaks are blue light emission and red light emission, respectively.

[0053] Example 9: This example provides the application of water-soluble blue-red dual-emission fluorescent silicon quantum dots in ratiometric biochemical analysis. The water-soluble blue-red dual-emission fluorescent silicon quantum dots prepared in Example 1 were used to test β-galactosidase activity. The specific implementation steps are as follows: (1) Mix 100 μL of enzyme substrate p-nitrophenyl-β-D-pyranogalactoside (2 mM), 200 μL of β-galactosidase with different activities and 50 μL of phosphate buffer solution (pH=6), and incubate at room temperature for 40 min.

[0054] (2) Add 100 μL of the water-soluble blue-red dual-emission fluorescent silicon quantum dots prepared in Example 1, 200 μL of phosphate buffer solution (pH=8) and 350 μL of deionized water to the solution obtained in step (1), mix well and let stand at room temperature for 1 min.

[0055] (3) Test the fluorescence spectra of the solution obtained in step (2) at excitation wavelengths of 360 nm and 560 nm respectively, and calculate the ratio I of fluorescence intensity at 470 nm and 660 nm. 470 / I 660 and draw I 470 / I 660 Curve showing changes in β-galactosidase activity.

[0056] See Figure 17 As can be seen from the figure, with the increase of β-galactosidase activity, the ratio I... 470 / I 660 Gradually decreasing. Ratio I 470 / I 660 The method exhibits a good linear relationship with β-galactosidase activity in the range of 1-150 U / L. It can detect β-galactosidase activity in real biological samples (such as urine) and can be used to screen for its inhibitors.

[0057] This method is based on the catalytic generation of p-nitrophenol from a substrate by a biological enzyme. p-Nitrophenol selectively quenches the blue light emission peak while having little effect on the red light emission peak, causing a change in the ratio of fluorescence signals. Therefore, by changing the enzymatic digestion substrate, it can be used to detect the activity of various biological enzymes.

[0058] Example 10: This example provides the application of water-soluble blue-red dual-emission fluorescent silicon quantum dots in fluorescent ink. The water-soluble blue-red dual-emission fluorescent silicon quantum dots prepared in Example 2 were used as the fluorescent ink for testing. The specific implementation steps are as follows: Take 5 mL of the water-soluble blue-red dual-emission fluorescent silicon quantum dot aqueous solution (concentration of 1.04 g / mL) prepared in Example 2 and 10 mg of PVA (polyvinyl alcohol), mix them evenly, use a pen to draw a certain amount of the mixed solution, write on paper, and a fluorescent image can be presented after being irradiated by ultraviolet light.

[0059] See Figure 18 As can be seen from the image, there are clear pink fluorescent characters, which can be used as fluorescent ink in the field of anti-counterfeiting.

[0060] Comparative Example 1: Green fluorescent silicon quantum dots were prepared using a one-step method, then coated with amino clay, and grafted with Eu. 3+(Emitting red fluorescence) Multi-emission fluorescent probes are prepared for ratio detection. The prepared silicon quantum dots have a single emission peak and a short emission wavelength, requiring complex modifications to construct ratio probes. However, the water-soluble blue-red dual-emission fluorescent silicon quantum dots of this invention do not require complex modifications; a single hydrothermal method is sufficient to prepare dual-emission silicon quantum dots. The preparation process is simple, low-cost, and covers the red light region. Ratio detection can be achieved using a single material, facilitating coupling with other portable systems such as optical fibers.

[0061] Comparative Examples 2 and 3: Both were prepared using a one-step hydrothermal method, resulting in dual-emission silicon quantum dots. The silicon quantum dots prepared in Comparative Example 2 emitted blue light (400 nm) and green light (510 nm), respectively, while those prepared in Comparative Example 3 emitted blue light (440 nm) and green light (520 nm). The dual emission peaks of the silicon quantum dots prepared in these two comparative examples showed significant spectral overlap and were located in the short wavelength region. In contrast, the water-soluble blue-red dual-emission fluorescent silicon quantum dots of this invention have dual emission peaks located in the blue light region (~470 nm) and the red light region (~660 nm), respectively. These dual emission peaks show almost no overlap, exhibiting high spectral resolution and covering the red light emission region. This indicates that the silicon quantum dots prepared in this invention possess stronger anti-interference capabilities and quantitative analysis capabilities.

[0062] In summary, the present invention has the following advantages over the prior art: Compared to Comparative Example 1: A sensitive visual intelligent fluorescence detection platform for tetracycline detection based on silicon quantum dots (Journal of Environmental Chemical Engineering, 2025, Volume 13, 116057), this invention prepares dual-emission silicon quantum dots in one step. This invention uses a one-step hydrothermal synthesis method to synthesize water-soluble blue-red dual-emission fluorescent silicon quantum dots with dual emission of blue light (470 nm) and red light (660 nm). Dual fluorescence signals can be obtained without recombination with other fluorescent materials. The preparation process is simple, and the emission wavelength in the red light region is longer.

[0063] Compared to Comparative Example 2: Dual-emissive silicon quantum dots as a ratiometric fluorogenic probe for alkaline phosphatase activity (Microchimica Acta, 2025, Volume 192, 780) and Comparative Example 3: A dual-emission silicon quantum dot and its preparation method and application (CN202311458759X), the water-soluble blue-red dual-emission fluorescent silicon quantum dots prepared in this invention have higher resolution of the two emission peaks and cover the red light emission region, which can effectively eliminate matrix interference.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-soluble blue-red dual-emission fluorescent silicon quantum dot, characterized in that, The preparation method is as follows: Using γ-glycidoxypropyltrimethoxysilane and Nile blue as precursors, a hydrothermal reaction was carried out, followed by purification and drying to obtain water-soluble blue-red dual-emission fluorescent silicon quantum dots with one emission peak in each of the blue and red light regions. The hydrothermal reaction temperature is 120℃-200℃, and the reaction time is 2h-20h; The molar ratio of Nile Blue and γ-glycidoxypropyltrimethoxysilane is 1:(332-1991).

2. The water-soluble blue-red dual-emission fluorescent silicon quantum dot according to claim 1, characterized in that, The purification method is dialysis.

3. The water-soluble blue-red dual-emission fluorescent silicon quantum dot according to claim 1, characterized in that, The drying method is freeze-drying or oven drying.

4. An application of the water-soluble blue-red dual-emission fluorescent silicon quantum dot according to claim 1 in the fields of biochemical analysis, cell imaging and anti-counterfeiting.

5. The application according to claim 4, characterized in that, The water-soluble blue-red dual-emission fluorescent silicon quantum dots are used as dual-signal fluorescent probes for biochemical analysis and / or cell imaging.

6. The application according to claim 5, characterized in that, Fluorescent inks are prepared using the water-soluble blue-red dual-emission fluorescent silicon quantum dots for use in the field of anti-counterfeiting.

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