Water-soluble quantum point under condition of phase transition, and preparation method

Abstract

This invention discloses a method for preparing water-soluble quantum dots in phase transfer condition. The water-soluble quantum dots are composed of oil-soluble quantum dots coated with amphiphilic surfactant to form a hydrophilic outer layer. The method comprises: utilizing quaternary ammonium salt amphiphilic surfactant as the phase-transfer agent, and transferring the quantum dots from oil phase to water phase. The water-soluble quantum dots have such advantages as high fluorescent intensity, narrow and symmetric fluorescent emission peak, high quantum yield, high stability, uniform dispersion and long storage life (2 months). The method has such advantages as simple process, good repeatability, and low cost. The water-soluble quantum dots can be used for biomedical analysis and detection such as fluorescent probe and cell imaging.

Description

technical field

[0001] The invention relates to the fields of nanomaterials and surface colloid chemistry, in particular to a water-soluble quantum dot under phase transfer conditions and a preparation method thereof. Background technique

[0002] Quantum dots, also known as semiconductor nanocrystals, are nanoparticles composed of II-VI or III-V group elements. CdX (X=S, Se, Te) is mainly studied more at present. Quantum dots have strong and stable fluorescence, wide excitation spectrum and narrow emission spectrum, and the emission wavelength can be adjusted by changing their particle size and composition. The advantages of sample self-luminescence and signal interference caused by light scattering make quantum dots have the prospect of replacing organic fluorescent dyes in the field of biomedicine. However, the oil-soluble quantum dots obtained by pyrolysis of the organic phase are incompatible with the aqueous environment of the biological system, which greatly limits ...

Examples

Embodiment 1

[0026] Embodiment 1: The preparation method of water-soluble CdSe quantum dots.

[0027] (1) Dissolve the oil-soluble CdSe quantum dots in chloroform or n-hexane to obtain a concentration of 10 -2 mol / L solution of oil-soluble quantum dots (A 1 solution), ready to use.

[0028] (2) Weigh 12.8 mg of didodecyl diquaternary ammonium salt surfactant and put it in a beaker, add an appropriate amount of distilled water and ultrasonically vibrate to make it dissolve completely, then set the volume in a 100mL volumetric flask to obtain 10 -3 mol / L aqueous solution of surfactant. Take 1mL of this solution with a pipette and dilute 10 times with distilled water to obtain a concentration of 10 -4 mol / L didodecyl diquaternary ammonium salt aqueous solution (B solution).

[0029] (3) Take 4mL of the above 10 -4 mol / L B solution in a vial, add a magnet, place it on a magnetic stirrer, stir 2mL of A at a speed of 1200rpm 1 The solution was dripped at a rate of 1 drop / second, and heated...

Embodiment 2

[0031] Embodiment 2: the preparation method of water-soluble CdSe quantum dots.

[0032] (1) Dissolve the oil-soluble CdSe quantum dots in chloroform or n-hexane to obtain a concentration of 10 -4 mol / L solution of oil-soluble quantum dots (A 2 solution), ready to use.

[0033] (2) Weigh 12.8 mg of didodecyl diquaternary ammonium salt surfactant and put it in a beaker, add an appropriate amount of distilled water and ultrasonically vibrate to make it dissolve completely, then set the volume in a 100mL volumetric flask to obtain 10 -3 mol / L aqueous solution of surfactant. Take 1mL of this solution with a pipette and dilute 10 times with distilled water to obtain a concentration of 10 -4 mol / L didodecyl diquaternary ammonium salt aqueous solution (B solution).

[0034] (3) Take 4mL of the above 10 -4 mol / L B solution in a vial, add a magnet, place it on a magnetic stirrer, stir 2mL of A at a speed of 1200rpm 2 The solution was dripped at a rate of 1 drop / second, and heated...

Embodiment 3

[0036] Embodiment 3: the preparation method of water-soluble CdSe quantum dots.

[0037] (1) Dissolve the oil-soluble CdSe quantum dots in chloroform or n-hexane to obtain a concentration of 10 -6 mol / L solution of oil-soluble quantum dots (A 3 solution), ready to use.

[0038] (2) Weigh 12.8 mg of didodecyl diquaternary ammonium salt surfactant and put it in a beaker, add an appropriate amount of distilled water and ultrasonically vibrate to make it dissolve completely, then set the volume in a 100mL volumetric flask to obtain 10-3 mol / L aqueous solution of surfactant. Take 1mL of this solution with a pipette and dilute 10 times with distilled water to obtain a concentration of 10 -4 mol / L didodecyl diquaternary ammonium salt aqueous solution (B solution).

[0039] (3) Take 4mL of the above 10 -4 mol / L B solution in a vial, add a magnet, place it on a magnetic stirrer, stir 2mL of A at a speed of 1200rpm 3 The solution was dripped at a rate of 1 drop / second, and heated t...

technical field

[0001] The invention relates to the fields of nanomaterials and surface colloid chemistry, in particular to a water-soluble quantum dot under phase transfer conditions and a preparation method thereof. Background technique

[0002] Quantum dots, also known as semiconductor nanocrystals, are nanoparticles composed of II-VI or III-V group elements. CdX (X=S, Se, Te) is mainly studied more at present. Quantum dots have strong and stable fluorescence, wide excitation spectrum and narrow emission spectrum, and the emission wavelength can be adjusted by changing their particle size and composition. The advantages of sample self-luminescence and signal interference caused by light scattering make quantum dots have the prospect of replacing organic fluorescent dyes in the field of biomedicine. However, the oil-soluble quantum dots obtained by pyrolysis of the organic phase are incompatible with the aqueous environment of the biological system, which greatly limits ...

Examples

Embodiment 1

[0026] Embodiment 1: The preparation method of water-soluble CdSe quantum dots.

[0027] (1) Dissolve the oil-soluble CdSe quantum dots in chloroform or n-hexane to obtain a concentration of 10 -2 mol / L solution of oil-soluble quantum dots (A 1 solution), ready to use.

[0028] (2) Weigh 12.8 mg of didodecyl diquaternary ammonium salt surfactant and put it in a beaker, add an appropriate amount of distilled water and ultrasonically vibrate to make it dissolve completely, then set the volume in a 100mL volumetric flask to obtain 10 -3 mol / L aqueous solution of surfactant. Take 1mL of this solution with a pipette and dilute 10 times with distilled water to obtain a concentration of 10 -4 mol / L didodecyl diquaternary ammonium salt aqueous solution (B solution).

[0029] (3) Take 4mL of the above 10 -4 mol / L B solution in a vial, add a magnet, place it on a magnetic stirrer, stir 2mL of A at a speed of 1200rpm 1 The solution was dripped at a rate of 1 drop / second, and heated...

Embodiment 2

[0031] Embodiment 2: the preparation method of water-soluble CdSe quantum dots.

[0032] (1) Dissolve the oil-soluble CdSe quantum dots in chloroform or n-hexane to obtain a concentration of 10 -4 mol / L solution of oil-soluble quantum dots (A 2 solution), ready to use.

[0033] (2) Weigh 12.8 mg of didodecyl diquaternary ammonium salt surfactant and put it in a beaker, add an appropriate amount of distilled water and ultrasonically vibrate to make it dissolve completely, then set the volume in a 100mL volumetric flask to obtain 10 -3 mol / L aqueous solution of surfactant. Take 1mL of this solution with a pipette and dilute 10 times with distilled water to obtain a concentration of 10 -4 mol / L didodecyl diquaternary ammonium salt aqueous solution (B solution).

[0034] (3) Take 4mL of the above 10 -4 mol / L B solution in a vial, add a magnet, place it on a magnetic stirrer, stir 2mL of A at a speed of 1200rpm 2 The solution was dripped at a rate of 1 drop / second, and heated...

Embodiment 3

[0036] Embodiment 3: the preparation method of water-soluble CdSe quantum dots.

[0037] (1) Dissolve the oil-soluble CdSe quantum dots in chloroform or n-hexane to obtain a concentration of 10 -6 mol / L solution of oil-soluble quantum dots (A 3 solution), ready to use.

[0038] (2) Weigh 12.8 mg of didodecyl diquaternary ammonium salt surfactant and put it in a beaker, add an appropriate amount of distilled water and ultrasonically vibrate to make it dissolve completely, then set the volume in a 100mL volumetric flask to obtain 10-3 mol / L aqueous solution of surfactant. Take 1mL of this solution with a pipette and dilute 10 times with distilled water to obtain a concentration of 10 -4 mol / L didodecyl diquaternary ammonium salt aqueous solution (B solution).

[0039] (3) Take 4mL of the above 10 -4 mol / L B solution in a vial, add a magnet, place it on a magnetic stirrer, stir 2mL of A at a speed of 1200rpm 3 The solution was dripped at a rate of 1 drop / second, and heated t...

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