Fluorescent aptasensor for detecting silver ion concentration and its preparation method and application

Abstract

The invention belongs to the field of fluorescent aptamer sensors, and particularly relates to a fluorescent aptamer sensor for detecting the concentration of silver ions as well as a preparation method and application of the fluorescent aptamer sensor. The fluorescent aptamer sensor is based on an advantage of high sensitivity of aptamer functionalization nano-gold and fluorescence detection technology; 40 nm gold is used as a quenching group to be connected with the end 5 of the probe I through Au-S; fAM is used as a fluorophore to be marked at the end 3 of the probe II, a fluorescent aptamer sensor for detecting the concentration of silver ions is constructed, and the silver ions with different concentrations in a water environment are detected, so that the detection performance of thesensor is verified. Experimental results show that the linear detection range of the sensor is 10-60 nmol / L, and the detection limit is 10 nmol / L.

Description

technical field [0001] The invention belongs to the field of fluorescent aptamer sensors, in particular to a fluorescent aptamer sensor for detecting silver ion concentration, a preparation method and application thereof. Background technique [0002] With its unique properties, silver is widely used in medical materials, photography, electronics, imaging and other industries. However, silver ions are listed as one of the most toxic heavy metal ions. When silver ions are discharged into soil and water sources along with industrial wastewater, they will be absorbed by plants, and then enter the human body along the food chain to interact with proteins and enzymes in the human body, seriously threatening human health. Therefore, detecting the concentration of silver ions in the water environment is very important to protect human life and health. [0003] Current methods for detecting the concentration of silver ions mainly rely on inductively coupled plasma mass spectrometr...

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Problems solved by technology

[0006] In order to solve the above-mentioned technical problems, the present invention proposes a fluorescent aptasensor for detecting the concentration of silver ions and its preparation method and application, and uses silver ions to form C-Ag with mismatched C bases in nucleic acid aptamers + The composite structure of -C, and the principle of the phenomenon of fluorescence energy transfer occurs when FAM-labeled DNA and nano-gold modified DNA can undergo complementary pairing in the presence of silver ions, thereby shortening the distance between nano-gold and FAM

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