Colorimetric detection method for activity of telomerase based on silver nanoprobe

Abstract

The invention discloses a colorimetric detection method for the activity of telomerase based on a silver nanoprobe. The silver nanoprobe comprises silver nanoparticles and blunt-end hybrid duplexes modifying the surfaces of the silver nanoparticles. Each of the hybrid duplexes is formed by hybridization of single-stranded DNAs and a nucleotide sequence complementary to the single-stranded DNAs; the single-stranded DNAs are formed by successive connection of a continuous cytosine strand, a spacer strand and a telomerase-binding substrate strand; and the nucleotide sequence is completely complementary to the telomerase-binding substrate strand. The surfaces of the silver nanoparticles are modified by the hybrid duplexes in virtue of the continuous cytosine strands. The silver nanoprobe prepared in the invention is liable to aggregation and displaying of grayness due to rigid structures of double-stranded DNAs on the surfaces of the silver nanoparticles and stacking effect of the blunt ends on the surfaces of the silver nanoparticles; under the action of telomerase, the telomerase-binding substrate strands are allowed to extend, so swinging DNA terminals are formed on the surfaces of the silver nanoparticles, which enables the silver nanoparticles to have better stability; and the silver nanoparticles are tend to be disperse and to display a yellow color.

Description

technical field [0001] The invention belongs to the field of analysis and detection, and in particular relates to a method for colorimetric detection of telomerase activity based on silver nano-probes. Background technique [0002] Human telomerase is a ribonucleoprotein composed of telomerase RNA and telomerase reverse transcriptase, which catalyzes the telomeric repeat sequence (TTAGGG) n Added at the 3' end of telomeres to compensate for the shortening of telomeres during cell division. Studies have shown that telomerase activity is overexpressed in most malignant tumor cells, which is the reason for the continuous division and even immortalization of tumor cells. As the most spectral marker of human tumors, detection of telomerase activity is extremely attractive in cancer disputes and treatments. Different techniques, including telomeric repeat amplification (TRAP), electrochemical methods, fluorescence methods, surface plasmon resonance, field-effect crystal sensors,...

AI Technical Summary

Problems solved by technology

However, the interaction between silver nanoparticles and traditional anchor groups such as sulfhydryl and amino groups is weak, and they are easily oxidized under modified conditions.

These defects make it difficult for silver nanoparticles to be stably modified with biomolecules, limiting their application in detection

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