CN104449698A - Quantum dot/titanium dioxide composite nanodot array having visible-light response and preparation method of quantum dot/titanium dioxide composite nanodot array - Google Patents

Abstract

The quantum dot/titanium dioxide composite nano-dot array with visible light response disclosed by the present invention is on the surface of the substrate. Each nano-dot in the composite nano-dot array is composed of titanium dioxide-wrapped visible light-responsive quantum dots. The size of the composite nano-dot is 50-200nm, and the density 0.31×10 ¹⁰ ~3.01×10 ¹⁰ cm ^-2 . The preparation process is a one-step method, that is, adding quantum dots when preparing the spin-coating solution, spin-coating it on the surface of the substrate by sol-gel spin-coating method, and preparing quantum dot/titanium dioxide composite nano-dot arrays by hydrothermal method or direct annealing. The process is simple and easy to realize. By adjusting the type of quantum dots and their excitation wavelength, the responsiveness and utilization rate of the composite nanodot array to light can be adjusted; and visible light of different wavelengths can be used to change the hydrophilicity and hydrophobicity of the surface of the material, so as to achieve later cell detachment and detachment for visible light. Attachment cells offer the possibility.

Description

Quantum dot/titanium dioxide composite nanodot array with visible light response and preparation method thereof

technical field

The invention belongs to the field of biomedical thin films, and in particular relates to a quantum dot/titanium dioxide composite nano-dot array with visible light response performance and a preparation method thereof.

Background technique

In recent years, due to the limitations of existing tissue engineering methods, cell sheet tissue engineering technology has attracted widespread attention. The traditional temperature-sensitive system obtains cell sheets by changing the temperature, and the technology develops rapidly, but the disadvantage is that there may be residues of toxic chemicals. Cell detachment can be achieved by changing the charge and hydrophobicity of the surface. Therefore, using light to change the hydrophilicity and hydrophobicity of the surface of a certain material is a more excellent method to obtain cell sheets. Titanium dioxide is non-toxic, has excellent biocompatibility and chemical stability. The band gap of anatase titanium dioxide is 3.2 eV, and ultraviolet light can change the hydrophilicity and hydrophobicity of the surface of the material. Therefore, cell sheets can be successfully obtained by irradiating titanium dioxide nanodot films with UV365 nm light (Yi Hong, Mengfei Yu, Wenjian Weng, et al. Light-induced cell detachment for cell sheet technology, Biomaterials, 34 (2013) 11-18) . However, ultraviolet light has certain toxicity to cells and may cause gene mutation, so this method also has certain defects. Therefore, visible light desorbed cells have attracted attention.

Quantum dots have strong photoluminescence, up-conversion and down-conversion fluorescence properties, and electron donor and acceptor properties. In the quantum dot/titanium dioxide composite nanodot array system, the upconversion fluorescence characteristics of quantum dots and the electron donor/acceptor properties can improve the visible light responsiveness of titanium dioxide, which provides the possibility for it to be used in the field of visible light desorption cells. the

Quantum dots are doped in the titanium dioxide nanodot system, and the quantum dots are wrapped in the nanodots by phase separation to form biomaterials that respond to visible light, and the composite nanodot array can be regulated by changing the type of quantum dots, excitation wavelength and preparation process The structure and response to visible light, and the study of the interaction between cells and materials or between cells are of great significance for the development of cell sheet desorption, tissue engineering, and cell biosensors.

Contents of the invention

The object of the present invention is to provide a visible light responsive quantum dot/titanium dioxide composite nano-dot array and a preparation method thereof.

The quantum dot/titanium dioxide composite nano-dot array with visible light response of the present invention is on the surface of the substrate. Each nano-dot in the composite nano-dot array is composed of titanium dioxide-wrapped visible light-responsive quantum dots. The size of the composite nano-dot is 50-200 nm, and the density 0.31×10 ¹⁰ ~3.01×10 ¹⁰ cm ^-2 .

The aforementioned substrate can be quartz glass, silicon wafer, tantalum wafer or medical titanium metal and its alloys.

The visible light responsive quantum dots are C quantum dots, CdS quantum dots, CdSe/ZnS quantum dots or CdS/ZnS quantum dots with an excitation wavelength of 360-500 nm.

The preparation method of the quantum dot/titanium dioxide composite nano-dot array with visible light response of the present invention has the following two schemes:

plan 1

A method for preparing a quantum dot/titanium dioxide composite nano-dot array with visible light response, comprising the following steps:

1) Add 5~100 μL acetylacetone, 1~100 μL deionized water, 30~300 μL quantum dot solution with a concentration of 5 μg/mL, and 100~1000 μL tetrabutyl titanate in 5~10 mL ethanol in sequence , 0.1-0.5 g polyvinylpyrrolidone, stirred at room temperature, and distilled to 10 mL with ethanol to obtain a precursor sol;

2) Spin-coat 10-20 μL of precursor sol on the surface of the substrate at a speed of 4000-10000 rpm, then place the sample in a muffle furnace, keep it at 400-700 °C for 0.5-10 h, take it out, and deionized water Rinse and dry; or age the sample at room temperature for 2-24 hours, put it into the inner tank of the hydrothermal kettle, add deionized water with 60-95% of the volume of the inner tank of the hydrothermal kettle, and keep it at 100-300°C for 1~ After 20 h, take it out, rinse with deionized water, and dry.

Scenario 2

A method for preparing a quantum dot/titanium dioxide composite nano-dot array with visible light response, comprising the following steps:

1) Add 100~1000 μL tetrabutyl titanate and 30~300 μL quantum dot solution with a concentration of 5 μg/mL in 1~5 mL ethanol for premixing to obtain a premixed solution;

2) Add 5-100 μL of acetylacetone, 1-100 μL of deionized water, 0.1-0.5 g of polyvinylpyrrolidone in turn to 1-10 mL of ethanol, stir at room temperature, and constant volume in ethanol to 10 mL to obtain the precursor sol;

3) Spin-coat 10-20 μL precursor sol on the surface of the substrate at a speed of 4000-10000 rpm, then place the sample in a muffle furnace, keep it at 400-700°C for 0.5-10 h, take it out, and rinse with deionized water , dry; or after aging the sample at room temperature for 2-24 hours, put it into the inner tank of the hydrothermal kettle, add deionized water with 60-95% of the volume of the inner tank of the hydrothermal kettle, and keep it at 100-300°C for 1-20 h, take it out, rinse with deionized water, and dry.

The present invention improves the responsiveness of titanium dioxide to visible light by compounding titanium dioxide and quantum dots: the preparation process of the present invention is a one-step method, that is, adding quantum dots when preparing the spin coating solution, and spin coating it on the substrate by sol-gel spin coating method Surface, hydrothermal method or direct annealing to prepare quantum dots/titania composite nanodot arrays. By adjusting the type of quantum dots and their excitation wavelength, the responsiveness and utilization of the composite nanodot array to light can be adjusted; and visible light of different wavelengths can be used to change the hydrophilicity and hydrophobicity of the surface of the material, so as to achieve later cell detachment. Therefore, the preparation method of the present invention is simple and easy to implement, and provides the possibility for visible light desorption of cells.

Description of drawings

Figure 1 is a SEM image of a titania nano-dot array.

Figure 2 is the SEM image of the C quantum dots/titanium dioxide composite nanodot array with an excitation wavelength of 360 nm.

Figure 3 is the SEM image of the C quantum dots/titanium dioxide composite nanodot array with an excitation wavelength of 470 nm.           

Fig. 4 is the UV-Vis curve of embodiment 1, embodiment 2 and embodiment 3.

the

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments and accompanying drawings, but the present invention is not limited thereto.

Example 1

1) Add 62 μL of acetylacetone, 36 μL of deionized water, 100 μL of tetrabutyl titanate, and 0.4 g of polyvinylpyrrolidone to 5 mL of ethanol in sequence, stir at room temperature, and dilute the volume of ethanol to 10 mL to obtain a precursor sol.

2) Spin-coat 20 μL of the above precursor sol on the surface of quartz glass at a speed of 8000 rpm; place the sample in a muffle furnace, keep it at 500 °C for 1 h, take it out, rinse with deionized water, and dry to obtain titanium dioxide nanodots array (see Figure 1). Its UV-Vis curve is shown in the solid line in Figure 4, and the absorption limit is 401 nm.

Example 2

1) Add 100 μL of acetylacetone, 1 μL of deionized water, 36 μL of C quantum dots with an excitation wavelength of 360 nm and a concentration of 5 μg/mL in 5 mL of ethanol, 680 μL of tetrabutyl titanate, 0.1 g of poly Vinylpyrrolidone was stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Spin-coat 15 μL of the above precursor sol on the surface of the silicon metal substrate at a speed of 6000 rpm; place the sample in a muffle furnace, keep it at 700°C for 0.5 h, take it out, rinse it with deionized water, and dry it to obtain C quantum dot/titania composite nanodot array (see Figure 2). Among them, the titanium dioxide nanodot size ranges from 70 to 200 nm. Fig. 4 dashed line is the UV-Vis curve of the C quantum dot/titanium dioxide composite nano-dot array that excitation wavelength is 360 nm, and its absorption limit is 419 nm, and embodiment 1 does not contain the titanium dioxide nano-dot array phase of visible light response quantum dot significantly red-shifted.

Example 3

1) Add 62 μL acetylacetone, 100 μL deionized water, 30 μL C quantum dots with an excitation wavelength of 470 nm and a concentration of 5 μg/mL to 5 mL ethanol, 1000 μL tetrabutyl titanate, 0.5 g poly Vinylpyrrolidone was stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Spin-coat 10 μL of the above precursor sol on the surface of the tantalum metal substrate at a speed of 10,000 rpm; place the sample in a muffle furnace, keep it at 400°C for 10 h, take it out, rinse it with deionized water, and dry it to obtain C quantum dot/titania composite nanodot array (Fig. 3). Among them, the titanium dioxide nanodot size ranges from 70 to 200 nm. The dotted line in Figure 4 is the UV-Vis curve of the C quantum dot/titanium dioxide composite nanodot array with an excitation wavelength of 470 nm, and its absorption limit is 431 nm, which is significantly red-shifted compared with the titanium dioxide nanodot array in Example 1.

Example 4

1) Add 5 μL acetylacetone, 36 μL deionized water, 300 μL CdS quantum dots with an excitation wavelength of 450 nm and a concentration of 5 μg/mL, 680 μL tetrabutyl titanate, 0.5 g poly Vinylpyrrolidone was stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Take 15 μL of the above precursor sol and spin-coat it on the surface of the medical titanium metal substrate at a speed of 4000 rpm; after aging the sample at room temperature for 6 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, add the liner 80% volume of deionized water was kept at 100°C for 20 h and then taken out to obtain CdS quantum dots/titanium dioxide composite nanodot arrays.

Example 5

1) Add 36 μL of CdSe/ZnS quantum dots with an excitation wavelength of 500 nm and a concentration of 5 μg/mL and 680 μL of tetrabutyl titanate premixed in 3 mL of ethanol; add 62 μL of acetylacetone in 4 mL of ethanol in sequence , 36 μL of deionized water, the above premix solution and 0.4 g of polyvinylpyrrolidone, stirred at room temperature, and dilute to 10 mL with ethanol to obtain the precursor sol.

2) Take 15 μL of the above precursor sol and spin-coat it on the surface of the medical titanium alloy substrate at a speed of 8000 rpm; after aging the sample at room temperature for 2 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, add the liner 60% volume of deionized water was kept at 120°C for 2 h and then taken out to obtain CdSe/ZnS quantum dots/TiO2 composite nanodot arrays.

Example 6

1) Add 72 μL CdS/ZnS quantum dots with an excitation wavelength of 500 nm and a concentration of 5 μg/mL and 680 μL tetrabutyl titanate premixed in 3 mL ethanol; add 62 μL acetylacetone, 100 μL of deionized water, the above premix solution and 0.4 g of polyvinylpyrrolidone were stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Take 15 μL of the above precursor sol and spin-coat it on the surface of the tantalum metal substrate at a speed of 8000 rpm; after aging the sample at room temperature for 24 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, add the volume of the liner 95% deionized water was kept at 300°C for 3 h and then taken out to obtain CdS/ZnS quantum dots/TiO2 composite nanodot arrays.

Example 7

1) In 5 mL ethanol, add 5 μL acetylacetone, 36 μL deionized water, 36 μL CdS quantum dots with an excitation wavelength of 450 nm and a concentration of 5 μg/mL, 680 μL tetrabutyl titanate, 0.5 g poly Vinylpyrrolidone was stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Take 15 μL of the above precursor sol and spin-coat it on the surface of quartz glass at a speed of 8000 rpm; age the sample at room temperature for 2 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, and add 60% of the volume of the liner The deionized water was kept at 120°C for 2 h, then taken out, rinsed with deionized water, and dried to obtain a CdS quantum dot/titanium dioxide composite nanodot array.

Example 8

1) In 5 mL ethanol, add 5 μL acetylacetone, 36 μL deionized water, 36 μL C quantum dots with an excitation wavelength of 360 nm and a concentration of 5 μg/mL, 680 μL tetrabutyl titanate, 0.5 g poly Vinylpyrrolidone was stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Spin-coat 15 μL of the above precursor sol on the surface of quartz glass at a speed of 8000 rpm; age the sample at room temperature for 24 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, and add 95% of the volume of the liner The deionized water was kept at 300°C for 3 h, then taken out, rinsed with deionized water, and dried to obtain C quantum dots/titanium dioxide composite nanodot arrays.

Example 9

1) Add 5 μL acetylacetone, 36 μL deionized water, 36 μL C quantum dots with an excitation wavelength of 470 nm and a concentration of 5 μg/mL, 680 μL tetrabutyl titanate, 0.5 g poly Vinylpyrrolidone was stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Spin-coat 15 μL of the above precursor sol on the surface of quartz glass at a speed of 8000 rpm; age the sample at room temperature for 24 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, and add 80% of the volume of the liner The deionized water was kept at 300°C for 3 h, then taken out, rinsed with deionized water, and dried to obtain C quantum dots/titanium dioxide composite nanodot arrays.

Example 10

Add 36 μL of CdSe/ZnS quantum dots with an excitation wavelength of 500 nm and a concentration of 5 μg/mL and 680 μL of tetrabutyl titanate premixed into 3 mL of ethanol; μL of deionized water, the above premix solution and 0.4 g of polyvinylpyrrolidone were stirred at room temperature, and the volume was adjusted to 10 mL with ethanol to obtain the precursor sol.

2) Take 15 μL of the above precursor sol and spin-coat it on the surface of the titanium metal substrate at a speed of 8000 rpm; age the sample at room temperature for 24 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, and add an inner liner with a volume of 80 % deionized water, kept at 120°C for 3 h, took out, rinsed with deionized water, and dried to obtain CdS/ZnS quantum dots/titanium dioxide composite nanodot arrays.

Example 11

Add 36 μL of CdS/ZnS quantum dots with an excitation wavelength of 500 nm and a concentration of 5 μg/mL in 3 mL of ethanol and 680 μL of tetrabutyl titanate for premixing; add 62 μL of acetylacetone (AcAc) in sequence in 4 mL of ethanol , 36 μL of deionized water, the above premix solution and 0.4 g of polyvinylpyrrolidone, stirred at room temperature, and dilute to 10 mL with ethanol to obtain the precursor sol.

2) Spin-coat 15 μL of the above precursor sol on the surface of the titanium alloy substrate at a speed of 8000 rpm; age the above sample for 24 h, put it into a hydrothermal kettle with a polytetrafluoroethylene liner, and add 80% of the volume of the liner deionized water, kept at 120°C for 2 h, then taken out, rinsed with deionized water, and dried to obtain CdS/ZnS quantum dots/titanium dioxide composite nanodot arrays.

Claims (5)

1. A quantum dot/titanium dioxide composite nano-dot array with visible light response, characterized in that the composite nano-dot array is on the surface of the substrate, and each nano-dot in the composite nano-dot array is composed of titanium dioxide-wrapped visible light-responsive quantum dots, the composite nano-dot The size is 50-200 nm, and the density is 0.31×10 ¹⁰ ~3.01×10 ¹⁰ cm ^-2 . 2. The quantum dot/titanium dioxide composite nano-dot array with visible light response according to claim 1, characterized in that the substrate is quartz glass, silicon wafer, tantalum wafer or medical titanium metal and alloys thereof. 3. The quantum dot/titanium dioxide composite nano-dot array with visible light response according to claim 1, wherein said visible light responsive quantum dot is C quantum dot, CdS quantum dot, CdSe quantum dot, CdS quantum dot, CdSe /ZnS quantum dots or CdS/ZnS quantum dots. 4. prepare the method for the quantum dot/titanium dioxide composite nano-dot array with visible light response described in claim 1, comprise the following steps: 1) Add 5~100 μL acetylacetone, 1~100 μL deionized water, 30~300 μL quantum dot solution with a concentration of 5 μg/mL, and 100~1000 μL tetrabutyl titanate in 5~10 mL ethanol in sequence , 0.1-0.5 g polyvinylpyrrolidone, stirred at room temperature, and distilled to 10 mL with ethanol to obtain a precursor sol; 2) Spin-coat 10-20 μL of precursor sol on the surface of the substrate at a speed of 4000-10000 rpm, then place the sample in a muffle furnace, keep it at 400-700 °C for 0.5-10 h, take it out, and deionized water Rinse and dry; or age the sample at room temperature for 2-24 hours, put it into the inner tank of the hydrothermal kettle, add deionized water with 60-95% of the volume of the inner tank of the hydrothermal kettle, and keep it at 100-300°C for 1~ After 20 h, take it out, rinse with deionized water, and dry. 5. prepare the method for the quantum dot/titanium dioxide composite nano-dot array with visible light response described in claim 1, comprise the following steps: 1) Add 100~1000 μL tetrabutyl titanate and 30~300 μL quantum dot solution with a concentration of 5 μg/mL in 1~5 mL ethanol for premixing to obtain a premixed liquid; 2) Add 5-100 μL of acetylacetone, 1-100 μL of deionized water, 0.1-0.5 g of polyvinylpyrrolidone in turn to 1-10 mL of ethanol, stir at room temperature, and constant volume in ethanol to 10 mL to obtain the precursor sol; 3) Spin-coat 10-20 μL precursor sol on the surface of the substrate at a speed of 4000-10000 rpm, then place the sample in a muffle furnace, keep it at 400-700°C for 0.5-10 h, take it out, and rinse with deionized water , dry; or after aging the sample at room temperature for 2-24 hours, put it into the inner tank of the hydrothermal kettle, add deionized water with 60-95% of the volume of the inner tank of the hydrothermal kettle, and keep it at 100-300°C for 1-20 h, take it out, rinse with deionized water, and dry.