Dye-sensitized near-infrared fluorescent quantum dot composite material and preparation method and application thereof

Abstract

The present invention discloses a dye-sensitized near-infrared fluorescent quantum dot composite material and a preparation method and application thereof. The dye-sensitized near-infrared fluorescent quantum dot composite material includes a composite material system formed by the combination of organic dye molecules and near-infrared fluorescent quantum dots. The present invention uses green and environmentally friendly organic dye molecules to achieve organic dye-sensitized enhancement of the fluorescent properties of near-infrared fluorescent quantum dots by energy transfer, does not require complex surface treatment of the material, and can intuitively see the experimental results by combining simple optical means. In addition, the present invention is easy to operate and implement, and can provide a new idea for the research and development of inorganic-organic system biological imaging and optical devices.

Description

Technical Field

[0001] The present invention relates to a fluorescent quantum dot, in particular to a dye-sensitized near-infrared fluorescent quantum dot composite material system and a preparation method thereof, as well as a method and application of enhancing the optical properties of the dye-sensitized near-infrared fluorescent quantum dots, belonging to the technical field of design of inorganic / organic interface material systems. Background Art

[0002] Quantum dots are a class of inorganic semiconductor nanomaterials with quantum size effects, which are widely used in solar cells, light-emitting diodes, photodetectors, biomedicine and other fields. Among them, the research on near-infrared fluorescent quantum dots (NIR QDs) in the fields of bioimaging and optoelectronic devices is increasing. It is worth noting that photoluminescence enhancement technology is one of the important research directions. The luminescence properties of quantum dots are closely related to the current material synthesis and preparation process, but when using existing quantum dots, the material defects generated during the material preparation process will lead to poor luminescence performance or low quantum efficiency of the material. Dye sensitization usually refers to the phenomenon that some organic dyes that match the conduction band and valence band energy of wide-bandgap semiconductors are adsorbed on the semiconductor surface, and the spectral response of the system is extended to visible light by using the strong absorption of organic dyes by visible light. The strategy of dye-sensitized quantum dots is adopted to enhance the fluorescence conversion efficiency by enhancing the light absorption ability of quantum dots or using energy transfer, thereby achieving the enhancement of the fluorescence properties of quantum dots. It provides a new idea for the component regulation, construction and design of quantum dot-dye molecule composite materials with excellent performance in the future. Summary of the invention

[0003] The main purpose of the present invention is to provide a dye-sensitized near-infrared fluorescent quantum dot composite material and a preparation method and application thereof, so as to overcome the shortcomings of the prior art.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0005] An embodiment of the present invention provides a dye-sensitized near-infrared fluorescent quantum dot composite material, which includes a composite material system formed by the combination of organic dye molecules and near-infrared fluorescent quantum dots.

[0006] The embodiment of the present invention also provides a method for preparing the dye-sensitized near-infrared fluorescent quantum dot composite material, which comprises:

[0007] A solution containing near-infrared fluorescent quantum dots is mixed with organic dye molecules to prepare the dye-sensitized near-infrared fluorescent quantum dot composite material.

[0008] The embodiment of the present invention also provides the application of the dye-sensitized near-infrared fluorescent quantum dot composite material in the fields of biological imaging or preparation of optoelectronic devices.

[0009] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0010] The present invention uses green and environmentally friendly organic dye molecules to achieve organic dye sensitization and enhance the fluorescence properties of near-infrared fluorescent quantum dots by energy transfer. It does not require complex surface treatment of the material. Combined with simple optical means, the experimental results can be intuitively seen. In addition, the present invention is easy to operate and implement, and can provide a new idea for the development of inorganic-organic system biological imaging and optical devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to illustrate the technical solution of the present invention in more detail, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention herein. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 is a transmission electron microscope image of Ag2S QDs in a typical embodiment of the present invention;

[0013] Figure 2 is a steady-state fluorescence emission spectrum of Ag2S QDs, IHAFe, and Ag2S QDs-IHAFe in a typical embodiment of the present invention;

[0014] Figure 3 is the UV-visible absorption spectrum of Ag2S QDs, IHAFe, and Ag2S QDs-IHAFe in a typical embodiment of the present invention;

[0015] Figure 4 It is a hydrated particle size spectrum of Ag2S and Ag2S QDs-IHAFe in a typical embodiment of the present invention;

[0016] Figure 5 It is the Zeta potential spectrum of Ag2S and Ag2S QDs-IHAFe in a typical embodiment of the present invention. DETAILED DESCRIPTION

[0017] In view of the defects of the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. It mainly uses the optical properties of near-infrared fluorescent quantum dots (NIR QDs) materials, adopts a composite material system of near-infrared fluorescent quantum dots and organic dye molecules for research and analysis, and uses the strategy of dye-sensitized quantum dots to achieve the enhancement of fluorescence properties through absorption enhancement or energy transfer. The technical solution, its implementation process and principle will be further explained as follows.

[0018] One aspect of an embodiment of the present invention provides a dye-sensitized near-infrared fluorescent quantum dot composite material including a composite material system formed by combining organic dye molecules and near-infrared fluorescent quantum dots.

[0019] The near-infrared fluorescent quantum dots (NIR QDs) used in the present invention and the organic dye molecules meet the requirements of fluorescence enhancement, and there are channels for electron transfer or hole transfer, or energy transfer paths, during the light excitation process, thereby achieving the fluorescence enhancement phenomenon of quantum dots.

[0020] In some embodiments, the near-infrared fluorescent quantum dots (NIR QDs) include any one or a combination of two or more of Ag2S, Ag2Se, Ag2Te, AgInSe2, AgAuSe, PbS, PbSe, Ag2Se@Ag2S, Ag2Te@Ag2S, PbS@Ag2S, PbSe@Ag2S, PbSe@Ag2Se, perovskite quantum dots and the like quantum dots, but are not limited thereto.

[0021] In some embodiments, the organic dye molecules include any one or a combination of two or more of iodoisohydroxamate iron (IHAFe), cyanine dyes (Cy7.5, Cy7, Cy5.5, Cy5, Cy3.5, Cy3, etc.), indocyanine green (ICG), indocyanines (IR-808, IR-806, IR-783, IR-820, IR-825, etc.), coumarin, etc., but are not limited thereto.

[0022] In some more preferred implementation cases, the dye-sensitized near-infrared fluorescent quantum dot composite material includes an Ag2S-iodine isohydroxamate iron composite system. The present invention utilizes the interaction between near-infrared fluorescent quantum dots and dye molecules, takes the Ag2S QDs-IHAFe (iodine isohydroxamate iron) composite system as a model, and realizes the IHAFe dye sensitization to enhance the fluorescence properties of Ag2SQDs by energy transfer. Based on the Ag2S-IHAFe composite system, the transient absorption test technology is used to analyze and study the exciton dynamics generated between each other, verify the dye-sensitized near-infrared fluorescent quantum dots and the mechanism of achieving fluorescence enhancement.

[0023] In some embodiments, the molar ratio of the organic dye molecules to the near-infrared fluorescent quantum dots is 1:1 to 3:1.

[0024] Furthermore, the hydrated particle size of the dye-sensitized near-infrared fluorescent quantum dot composite material is 10 to 200 nm.

[0025] Another aspect of the embodiments of the present invention further provides a method for preparing the aforementioned dye-sensitized near-infrared fluorescent quantum dot composite material, comprising:

[0026] A solution containing near-infrared fluorescent quantum dots is mixed with organic dye molecules to prepare the dye-sensitized near-infrared fluorescent quantum dot composite material.

[0027] Furthermore, the solution containing near-infrared fluorescent quantum dots is an aqueous solution of near-infrared fluorescent quantum dots, wherein the concentration of the near-infrared fluorescent quantum dots is 1 g / L to 5 g / L.

[0028] Furthermore, the preparation method specifically comprises: adding organic dye molecules to a solution containing near-infrared fluorescent quantum dots, and ultrasonicating for 30 minutes to 3 hours to obtain the dye-sensitized near-infrared fluorescent quantum dot composite material.

[0029] In some more preferred implementation cases, a method for preparing a Ag2S QDs-IHAFe composite system material is as follows:

[0030] Source of near-infrared fluorescent quantum dots: laboratory synthesis or commercial purchase

[0031] Source of organic dye molecules: laboratory synthesis or commercial purchase

[0032] The Ag2S QDs-IHAFe composite material system was used as a model system to study the fluorescence properties of dye-sensitized near-infrared fluorescent quantum dots.

[0033] The water-soluble dye IHAFe was added to the water-soluble Ag2S QDs-MUA system, and the changes in its fluorescence properties were detected using steady-state fluorescence spectroscopy and UV-visible absorption spectroscopy. The transient absorption test technology was used to verify the mechanism of dye-sensitized near-infrared fluorescent quantum dots.

[0034] Infrared spectroscopy, hydrated particle size test, Zeta potential test and other techniques were used to verify the surface interaction between the dye molecule IHAFe and Ag2SQDs.

[0035] Another aspect of the embodiments of the present invention further provides the application of the aforementioned dye-sensitized near-infrared fluorescent quantum dot composite material in the fields of biological imaging or preparation of optoelectronic devices.

[0036] Through the above technical scheme, the present invention uses a composite system of near-infrared fluorescent quantum dots and organic dye molecules to study the fluorescence properties of dye-sensitized near-infrared fluorescent quantum dots, and confirms the effectiveness and feasibility of the strategy of enhancing fluorescence properties by dye-sensitized near-infrared fluorescent quantum dots in the present invention through verification methods such as steady-state fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, and transient absorption spectroscopy.

[0037] In addition, the photoluminescence enhancement technology in the near-infrared spectral region provided by the present invention has broad application prospects in the fields of biological imaging, optoelectronic devices, etc., and provides a new idea for the component regulation, construction and design of the preparation of inorganic-organic composite materials with excellent performance in the future.

[0038] In order to better understand the purpose and characteristics of the present invention, the technical solution of the present application is described in more detail below in conjunction with the accompanying drawings and several embodiments, but it should be noted that the contents of the following embodiments are illustrative rather than limiting implementation methods and do not limit the scope of the present application. In addition, unless otherwise specified, the various raw materials, reaction methods, etc. used in the following embodiments are all known in the art.

[0039] Example 1

[0040] 1. Preparation of composite materials of dye-sensitized near-infrared fluorescent quantum dots

[0041] The method of enhancing fluorescence properties by dye-sensitizing near-infrared fluorescent quantum dots is preferably an inorganic-organic composite material model. In this embodiment, a near-infrared quantum dot Ag2S QDs-IHAFe molecular composite material system is used as the research verification system of the present invention.

[0042] According to the preparation method of Ag2S QDs in the literature (J.Am.Chem.Soc.2010,132,5,1470-1471), 1200nm Ag2S QDs were prepared and the corresponding experimental operations were carried out. Transmission electron microscopy (TEM) was used for characterization. The results are shown in Figure 1 The organic dye molecules used can independently synthesize IHA precursor molecules, which chelate with FeCl3 to form iodoisohydroxamate iron dye molecules (IHAFe).

[0043] Preparation of the model Ag2S QDs-IHAFe material system: Add an aqueous solution of IHAFe to an aqueous solution of Ag2S QDs-MUA and ultrasonicate for half an hour to obtain a QDs-IHAFe composite system model.

[0044] 2. Analysis of the surface interaction between dye molecule IHAFe and Ag2S QDs-MUA

[0045] Corresponding experimental analysis and verification were carried out using infrared spectroscopy, hydrated particle size test, Zate potential test and other techniques, and it was confirmed that IHAFe interacted with the surface of Ag2S QDs-MUA.

[0046] For the steady-state fluorescence emission spectra of Ag2S QDs, IHAFe, and Ag2S QDs-IHAFe in this example, please refer to Figure 2 , UV-visible absorption spectrum as Figure 3As shown in Figure 2, the hydrated particle size spectra of Ag2S and Ag2S QDs-IHAFe are as follows: Figure 4 As shown, the Zeta potential spectrum is as follows Figure 5 shown.

[0047] 3. Study the mechanism of fluorescence enhancement of Ag2S QDs sensitized by dye molecule IHAFe

[0048] Using 785nm as the pump source to selectively excite QDs and QDs-IHAFe, the transient absorption spectrum obtained by the transient absorption spectrometer (TA) can be used to analyze the corresponding exciton dynamics process, and the energy transfer phenomenon in the system can be observed.

[0049] Example 2

[0050] In this embodiment, a near-infrared quantum dot AgAuSe QDs-ICG dye molecule composite system is used as the research verification system of the present invention. According to the preparation method of AgAuSe QDs in the literature (J.Am.Chem.Soc.2021,143,2601-2607), 980nm AgAuSe QDs are prepared for corresponding experimental operations, and transmission electron microscopy (TEM) characterization is adopted. The organic dye molecule ICG used can be obtained by commercial purchase.

[0051] Preparation of the model AgAuSe QDs-ICG material system: Add the organic dye molecule ICG to the aqueous solution of AgAuSe QDs and ultrasonicate for half an hour to obtain the AgAuSe QDs-ICG composite system model.

[0052] Corresponding experimental analysis and verification were carried out using infrared spectroscopy, hydrated particle size test, Zate potential test and other techniques, and it was confirmed that the ICG dye molecules interacted with the surface of AgAuSe QDs.

[0053] The phenomenon of fluorescence enhancement of AgAuSe QDs sensitized by dye molecule ICG was observed using steady-state fluorescence emission spectroscopy and UV-visible absorption spectroscopy.

[0054] Using 808nm as the pump source to selectively excite AgAuSe QDs and AgAuSe QDs-ICG, the transient absorption spectrum obtained by transient absorption spectrometer (TA) and the analysis of the corresponding exciton dynamics process revealed the existence of energy transfer in the system.

[0055] Example 3

[0056] In this embodiment, a near-infrared quantum dot Ag2Te@Ag2S QDs-IHAFe dye molecule composite system is used as the research verification system of the present invention. According to the preparation method of Ag2Te@Ag2S QDs in the literature (DOI: 10.1002 / smll.202001003), 1300nm Ag2Te@Ag2S QDs are prepared for corresponding experimental operations, and transmission electron microscopy (TEM) characterization is adopted. The organic dye molecule IHAFe used can be synthesized in the laboratory.

[0057] Preparation of the model Ag2Te@Ag2S QDs-IHAFe material system: Add the organic dye molecule IHAFe to the aqueous solution of Ag2Te@Ag2S QDs, and ultrasonicate for half an hour to obtain the Ag2Te@Ag2S QDs-IHAFe composite system model.

[0058] Corresponding experimental analysis and verification were carried out using infrared spectroscopy, hydrated particle size test, Zate potential test and other techniques, and it was confirmed that the IHAFe dye molecules interacted with the surface of Ag2Te@Ag2S QDs.

[0059] Steady-state fluorescence emission spectroscopy and UV-visible absorption spectroscopy were used to observe the phenomenon of fluorescence enhancement of Ag2Te@Ag2S QDs sensitized by dye molecule IHAFe.

[0060] Using 785nm as the pump source to selectively excite Ag2Te@Ag2S QDs and Ag2Te@Ag2S QDs-IHAFe, the transient absorption spectra obtained by transient absorption spectrometer (TA) and the analysis of the corresponding exciton dynamics process revealed the existence of energy transfer in the system.

[0061] Example 4

[0062] In this embodiment, a near-infrared quantum dot PbS QDs-Cy7.5 dye molecule composite system is used as the research verification system of the present invention, wherein PbS QDs are purchased commercially, 1300nm PbS QDs are prepared for corresponding experimental operations, and transmission electron microscopy (TEM) characterization is adopted. The organic dye molecule Cy7.5 used is obtained by commercial purchase.

[0063] Preparation of the model PbS QDs-Cy7.5 material system: Add the organic dye molecule Cy7.5 to the aqueous solution of PbS QDs and ultrasonicate for half an hour to obtain the PbS QDs-Cy7.5 composite system model.

[0064] Corresponding experimental analysis and verification were carried out using infrared spectroscopy, hydrated particle size test, Zate potential test and other techniques, and it was confirmed that Cy7.5 dye molecules interacted with the surface of PbS QDs.

[0065] Steady-state fluorescence emission spectroscopy and UV-visible absorption spectroscopy were used to observe the phenomenon of fluorescence enhancement of PbSQDs sensitized by organic dye molecule Cy7.5.

[0066] 808nm was used as a pump source to selectively excite PbS QDs and PbS QDs-Cy7.5. The transient absorption spectrum obtained by transient absorption spectrometer (TA) and the analysis of the corresponding exciton dynamics process revealed the existence of energy transfer in the system.

[0067] Example 5

[0068] In this embodiment, a near-infrared quantum dot PbS@Ag2S QDs-IHAFe dye molecule composite system is used as the research verification system of the present invention. PbS@Ag2S QDs are prepared by laboratory synthesis, and 1200nm PbS@Ag2S QDs are prepared by corresponding experimental operations and transmission electron microscopy (TEM) characterization. The organic dye molecule IHAFe used can be prepared by laboratory synthesis.

[0069] Preparation of the model PbS@Ag2S QDs-IHAFe material system: Add the organic dye molecule IHAFe to the aqueous solution of PbS@Ag2S QDs, and ultrasonicate for half an hour to obtain the PbS@Ag2S QDs-IHAFe composite system model.

[0070] Corresponding experimental analysis and verification were carried out using infrared spectroscopy, hydrated particle size test, Zate potential test and other techniques, and it was confirmed that the IHAFe dye molecules interacted with the surface of PbS@Ag2S QDs.

[0071] Steady-state fluorescence emission spectroscopy and UV-visible absorption spectroscopy were used to observe the phenomenon of fluorescence enhancement of PbS@Ag2SQDs sensitized by dye molecule IHAFe.

[0072] Using 785nm as the pump source to selectively excite PbS@Ag2S QDs and PbS@Ag2S QDs-IHAFe, the transient absorption spectra obtained by transient absorption spectrometer (TA) and the analysis of the corresponding exciton dynamics process revealed the existence of energy transfer in the system.

[0073] Example 6

[0074] In this embodiment, a near-infrared quantum dot AgAuSe QDs-IR-808 dye molecule composite system is used as the research verification system of the present invention. According to the preparation method of AgAuSe QDs in the literature (J.Am.Chem.Soc.2021,143,2601-2607), 1100nm AgAuSe QDs are prepared for corresponding experimental operations, and transmission electron microscopy (TEM) characterization is adopted. The organic dye molecule IR-808 used can be obtained by commercial purchase.

[0075] Preparation of the model AgAuSe QDs-IR-808 material system: Add the organic dye molecule IR-808 to the aqueous solution of AgAuSe QDs and ultrasonicate for half an hour to obtain the AgAuSe QDs-IR-808 composite system model.

[0076] Corresponding experimental analysis and verification were carried out using infrared spectroscopy, hydrated particle size test, Zate potential test and other techniques, and it was confirmed that IR-808 dye molecules interacted with the surface of AgAuSe QDs.

[0077] The phenomenon of fluorescence enhancement of AgAuSeQDs sensitized by dye molecule IR-808 was observed using steady-state fluorescence emission spectroscopy and UV-visible absorption spectroscopy.

[0078] Using 808nm as the pump source to selectively excite AgAuSe QDs and AgAuSe QDs-IR-808, the transient absorption spectrum obtained by transient absorption spectrometer (TA) and the analysis of the corresponding exciton dynamics process revealed the existence of energy transfer in the system.

[0079] In summary, the present invention uses the strategy of dye-sensitized near-infrared fluorescent quantum dots to achieve the purpose of photoluminescence enhancement. By verifying the interface interaction of the Ag2S-IHAFe composite system, the mechanism of fluorescence enhancement of the composite system is studied, and the fluorescence enhancement can be achieved by means of energy transfer. This method provides a new idea for the future research and development of bioimaging, optoelectronic devices and other fields using quantum dot-dye molecule composite material systems.

[0080] In addition, the inventors of this case also conducted experiments with other raw materials and conditions listed in this specification, referring to the methods of Examples 1 to 6. For example, Ag2Se, AgInSe2, PbSe, Ag2Se@Ag2S, Ag2Te@Ag2S, PbSe@Ag2S, PbSe@Ag2Se, perovskite quantum dots, etc. were used to replace Ag2Te, AgAuSe, PbS, PbS@Ag2S, etc. in the aforementioned embodiments, and a dye-sensitized near-infrared fluorescent quantum dot composite material system with the same technical effect as mentioned above was also prepared.

[0081] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. For example, the parts not described in this specification can be implemented by adopting or drawing on existing technologies, so all equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A dye-sensitized near-infrared fluorescent quantum dot composite material, characterized in that: The invention comprises a composite material system formed by combining organic dye molecules and near-infrared fluorescent quantum dots, wherein the composite material system is an Ag2S-iron iodine hydroxamate composite system, the organic dye molecules are iron iodine hydroxamate, the near-infrared fluorescent quantum dots are Ag2S, and the molar ratio of the organic dye molecules to the near-infrared fluorescent quantum dots is 1:1 to 3:

1.

2. The dye-sensitized near-infrared fluorescent quantum dot composite material according to claim 1, characterized in that: The hydrated particle size of the dye-sensitized near-infrared fluorescent quantum dot composite material is 10-200 nm.

3. The method for preparing the dye-sensitized near-infrared fluorescent quantum dot composite material according to any one of claims 1 to 2, characterized in that: include: A solution containing near-infrared fluorescent quantum dots is mixed with organic dye molecules to prepare the dye-sensitized near-infrared fluorescent quantum dot composite material.

4. The preparation method according to claim 3, characterized in that: The solution containing near-infrared fluorescent quantum dots is an aqueous solution of near-infrared fluorescent quantum dots, wherein the concentration of the near-infrared fluorescent quantum dots is 1 g / L to 5 g / L.

5. The preparation method according to claim 3, characterized in that: include: Organic dye molecules are added to a solution containing near-infrared fluorescent quantum dots, and ultrasonication is performed for 30 minutes to 3 hours to obtain the dye-sensitized near-infrared fluorescent quantum dot composite material.

6. Use of the dye-sensitized near-infrared fluorescent quantum dot composite material according to any one of claims 1 to 2 in the preparation of optoelectronic devices.

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