US 9,068,084 B2 · Silica nanoparticles doped with dye having negative charge and preparing method thereof

Abstract

Provided are silica nanoparticles doped with dyes having a negative charge by using cationic polyelectrolyte as templet and preparing method thereof. The nanoparticles have a core-shell structure, inner core comprises cationic polyelectrolyte aggregates, in which fluorescent dye having a negative charge and SiO2 are doped, and optional additive having a negative charge, the shell is consisted of SiO2, wherein the sum of negative charge carried by the additives and the fluorescent dye is less than that of positive charge carried by the polyelectrolyte aggregates. The preparing method comprises the following steps: preparing complex solution of polyelectrolyte and fluorescent dye; prehydrolysis of organosilicon source; coating with organosilicon source. The method can be applied to dope silica with various fluorescent dyes having a negative charge. Various dyes can be doped at the same time, the doping amount, and particle diameter and shape of the product can be controlled by the method. The nanoparticles are spherical, the particle diameter thereof is uniform, and colloid formed therefrom is stable.

Claims21

Dependent claims

A silica nanoparticle doped with negatively charged dyes using positively charged polyelectrolyte as template, which has a shell-core structure, wherein the inner core comprises:

positively charged polyelectrolyte aggregates, in which fluorescent dyes with negative charge and SiO2 are doped, and optional additives having negative charges;
the shell consists of SiO2;
and
wherein the sum of the amount of negative charges carried by the additives and the fluorescent dyes is less than amount of the positive charges carried by the polyelectrolyte aggregates.

1 more element

A method for preparing silica nanoparticles doped with negatively charged dyes by using positively charged polyelectrolyte as template, comprises the following steps:

1) preparation of composite solution of polyelectrolyte and fluorescent dye:
adding positively charged polyelectrolyte solution into ethanol/water mixture and adding negatively charged fluorescent dye solution while stirring, so as to obtain a composite solution of polyelectrolyte and fluorescent dye, wherein the amount of negative charges carried by the fluorescent dye is less than that of the positive charges carried by the polyelectrolyte aggregates;
2) prehydrolysis of organosilicon source:
adding ethanol, water and ammonia water into another container, adding siloxane while stirring to form a prehydrolysis system of siloxane;
and
3) coating with organosilicon source:
adding the composite solution of polyelectrolyte and fluorescent dye obtained from step 1) into the prehydrolysis system of siloxane obtained from step 2), continuing reacting while stirring, so as to obtain silica nanoparticles doped with negatively charged dyes by using positively charged polyelectrolyte as template.

4 more elements

Dependencies are inferred from the claim text.

Silica nanoparticles doped with dye having negative charge and preparing method thereof

Life of this patent

Silica nanoparticles doped with dye having negative charge and preparing method thereof

Life of this patent

Abstract

Claims21