Novel Raman probe and preparation method thereof

Abstract

The invention belongs to the technical field of preparation and application of Raman probes, and discloses a novel Raman probe and a preparation method thereof. The method comprises the steps of synthesizing a DNA triangular pyramid, and combining the DNA triangular pyramid with nanogold modified with quaternary ammonium salt under the electrostatic action; and combining a thiol-containing Raman probe 5,5'-dithio-bis-(2-nitrobenzoic acid) with the nanogold to obtain the novel Raman probe. The probe is combined with an EpCAM aptamer chain, so that the detection of circulating tumor cells (CTCs) can be realized. The detection of human breast cancer cells MCF-7 under the background of a large number of negative cells and the detection of the cells MCF-7 in a human peripheral blood environment are realized; and the problems that in the prior art, the probe is low in detection accuracy of the CTCs, poor in practicality and low in sensitivity of target detection, cannot avoid cross hybridization, is weak in repeatability, and is long in detection time and high in price due to enzymatic catalysis for signal amplification during detection are solved.

Description

technical field [0001] The invention belongs to the technical field of Raman probe preparation and application, and in particular relates to a novel Raman probe and a preparation method thereof. Background technique [0002] Currently, the closest prior art: [0003] (1) Prior art one (Song, J.; Park, S.; Kim, S.; Im, K.; Park, N. Electrostatic Interaction Driven Gold Nanoparticle Assembly on Three-dimensional Triangular Pyramid DNA Nanostructures. New J. Chem. 2017, 41, 9590-9593.) It is proposed that a three-dimensional DNA structure is formed through hybridization and enzyme linkage, and the electrostatic interaction makes the gold nanoparticles and the DNA triangular pyramid structure successfully assembled. This method allows the plasmonic absorption peaks of the assembled nanocomposites to be tuned from visible light to near-infrared by simply controlling the mixing ratio of gold nanoparticles and DNA, and exhibits a strong surface plasmon resonance effect in the near...

AI Technical Summary

Problems solved by technology

[0006] (1) The probes of the prior art do not bind to the EpCAM aptamer chain, and the detection accuracy of circulating tumor cell CTCs is low

And the probe practicability of prior art is poor

[0007] (2) The existing technology has not been applied to surface-enhanced Raman, but only the simple synthesis of the required DNA triangular pyramid and positively charged quaternary ammonium salt and the study of surface plasmon properties under the action of near-infrared light

[0008] (3) Due to the lack of plasma effect, the probes of the prior art produce weak Raman signals, and the sensitivity of detecting target objects is not high

The probes of the prior art cannot avoid cross-hybridization, and the reproducibility is weak

[0009] (4) The probes of the prior art often require enzyme catalysis for signal amplification during detection, and the detection time is long and expensive

[0013] Due to the low accuracy rate and poor probe practicability of the probes in the prior art for the detection of circulating tumor cell CTCs; the generated Raman signal is weak, and the sensitivity of detecting the target is not high; cross-hybridization cannot be avoided, and the repeatability is weak; Enzyme catalysis is often required for signal amplification during detection, which takes a long time and is expensive

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