Method for preparing two-waveband single-photon and two-photon fluorescent carbon quantum dots and application

Abstract

The invention provides a method for preparing two-waveband single-photon and two-photon fluorescent carbon quantum dots and application, and the method comprises the following steps: preparing an o-phenylenediamine solution or a mixed solution of the o-phenylenediamine and an acid; putting the o-phenylenediamine solution or the o-phenylenediamine mixed solution into a reaction kettle, heating, reacting to obtain a product, and carrying out centrifugal separation on the product to obtain the two-waveband fluorescent carbon quantum dots with single-photon and two-photon fluorescence emission characteristics at the same time. The preparation method disclosed by the invention is simple, economical and easy to operate, can be used for preparing two-waveband long-waveband fluorescence luminous carbon quantum dots at one time, has the characteristics of long-waveband single-photon and two-photon fluorescence excitation and emission, and has a good application prospect in the biomedical fieldsof fluorescence labeling of biological cells and tissues, living body imaging and the like.

Description

technical field [0001] The invention relates to the field of fluorescent material synthesis, in particular to a method and application for preparing two-band single-photon and two-photon fluorescent carbon quantum dots. Background technique [0002] Fluorescent nanoparticles have good application prospects in the important fields of biomedicine, LED luminescence, and metal ion detection. However, traditional organic fluorescent dyes have poor stability and are prone to photocatalytic degradation. Semiconductor quantum dot materials have good photostability and high fluorescence yield. However, they have poor solubility in aqueous solution and contain heavy metal elements such as Se, Te, and Cd, which will cause serious damage to human health and environmental pollution. This severely limits the application range of semiconductor quantum dot materials. [0003] As a new type of fluorescent nanoparticle, carbon quantum dots have a series of excellent properties such as tunabl...

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Problems solved by technology

This advantage makes it have better application prospects in the fields of LED luminescence, bioluminescent labeling, and metal ion detection compared with dyes and semiconductor quantum dots. However, the luminescence of fluorescent carbon quantum dots currently prepared still has many shortcomings, such as : The fluorescence emission of carbon quantum dots still requires short-wavelength, even ultraviolet wavelength excitation; the luminescence of carbon quantum dots is mostly limited to short-wavelength regions such as blue-green light; the photoluminescence of carbon quantum dots is mostly single-photon fluorescence emission excited by short-wavelength light sources ; Due to the low penetration of short-wavelength luminescence in biological tissues / aqueous solutions, and the shortcomings of ultraviolet excitation that easily lead to photodamage and photobleaching, carbon quantum dots are severely limited and their practical applications are hindered.

[0004] After retrieval, it was found that the Chinese patent with the application number CN201910302426 disclosed a blue fluorescent carbon quantum dot and its preparation method and application. However, the fluorescence excitation wavelength of the carbon quantum dot is (λ ex ) is ultraviolet light (381nm), fluorescence emission wavelength (λ em ) is blue light (467nm), and short-wavelength luminescence has low penetration in biological tissues / water solutions, and ultraviolet excitation can easily lead to photodamage and photobleaching.

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