DNA fluorescent probe and preparation thereof

Abstract

The invention relates to a DNA fluorescent probe and a preparation method thereof. The DNA fluorescent probe is characterized in that semiconductor light emitting nanoparticles CdTe / CdS / ZnS are used as a fluorescence emitting energy feeder, gold nanoparticles are used as a fluorescence absorbing energy receptor, and the CdTe / CdS / ZnS nanoparticles are connected with single-chain NH2-DNA, thus forming CdTe / CdS / ZnS-DNA; the gold nanoparticles are connected with single-chain SH-DNA, thus forming Au-DNA; the single-chain SH-DNA and the NH2-DNA are complementary to each other, and the DNA fluorescent probe is formed by hybridization of the CdTe / CdS / ZnS-DNA and Au-DNA. The preparation method of the DNA fluorescent probe firstly prepares the semiconductor light emitting nanoparticles CdTe / CdS / ZnS and the CdTe / CdS / ZnS-DNA, prepares the gold nanoparticles and the Au-DNA nanoparticles, connects the CdTe / CdS / ZnS-DNA (energy feeder) and the Au-DNA (energy receptor), and finally prepares the DNA fluorescent probe.

Description

technical field [0001] The invention relates to bioengineering technology, in particular to a DNA fluorescent probe based on the principle of fluorescence resonance energy transfer and a preparation method thereof. The DNA probe can be used to detect some small molecular living substances with characteristic DNA sequences in a liquid environment. Background technique [0002] In recent years, molecular biology has developed rapidly, new technologies have emerged, and their applications have become increasingly widespread. In particular, the potential application prospects of rapid, simple and accurate detection of gene sequences in the research fields of medical clinical laboratory science, immunology, and biology have attracted international attention. widespread interest in the scientific community. For the detection of living substances with specific DNA sequences, traditional methods mainly use radiolabeling and polymerase chain reaction (PCR). Due to its complex techno...

AI Technical Summary

Problems solved by technology

However, the use of this donor-acceptor pair still has the following disadvantages: 1. Their excitation spectra are narrow, and it is difficult to excite multiple components at the same time; 2. The organic fluorescent molecules of organic dyes have a wide spectrum and asymmetric distribution, which gives It is difficult to distinguish the source of organic fluorescent molecules of different probe molecules, and it is impossible to detect multiple components at the same time; 3. Specific wavelength excitation is required to emit fluorescence. If multiple diseases are detected at the same time, light excitation with different wavelengths is required.

The disadvantage is that using CdSe / ZnS as the energy donor and DABCYL as the quencher, the effective signal obtained is relatively low. Compared with the background signal (noise signal), its energy transfer efficiency needs to be further improved

In addition, since the maximum excitation wavelength of quantum dots used in the experiment is around 490nm, and the maximum absorption wavelength of gold nanoparticles is around 525nm, the overlapping ratio of its absorption and emission spectra is very low, resulting in low quenching efficiency and excessive background signal.

These energy donors are reported based on quantum dots. Due to the problems of the energy donor-acceptor itself and the defects in the design of the donor-acceptor pair, the quantum efficiency is generally low, and the sensitivity of the sensing system is not high.

Therefore, the above-mentioned energy donor-acceptor system and probes still need to be improved.