Double-circulation cascade signal amplification DNA (deoxyribonucleic acid) combination probe composition on basis of exonuclease III assistance, method for preparing double-circulation cascade signal amplification DNA combination probe composition and application thereof

Abstract

The invention discloses a double-circulation cascade signal amplification DNA (deoxyribonucleic acid) combination probe composition on the basis of exonuclease III assistance. The double-circulation cascade signal amplification DNA combination probe composition comprises a triggering DNA probe, a hairpin DNA probe, a mercury ion recognition probe and exonuclease III. The triggering DNA probe contains sequences formed by G-quadruplex; a 3' end and a 5' end of the hairpin DNA probe are complementary to each other to form a stem-shaped zone, and sequences of an annular zone are complementary to the triggering DNA probe. A large quantity of G-quadruplex DNA probes can be generated in two spontaneous circulation procedures after a small quantity of Hg2+ is triggered, and are bound with heme to generate G-quadruplex-heme DNA enzymes, ABTS-H2O2 reaction can be catalyzed, and light green ABTS+ which can be visually observed or can be measured by the aid of spectrophotometry processes can be generated; a method for preparing the double-circulation cascade signal amplification DNA combination probe composition is extremely high in sensitivity and specificity, high in detection speed, easy to implement and suitable to be developed to obtain environmental monitoring field real-time analysis technologies; the double-circulation cascade signal amplification DNA combination probe composition is particularly suitable for environments where diversified heavy metal ions are simultaneously available and is applicable to Hg ion monitoring environments when diversified metal pollutants are available.

Description

technical field [0001] The invention belongs to the field of biological detection, and relates to a double-cycle tandem signal amplification DNA combination probe composition assisted by exonuclease III, a preparation method and an application Background technique [0002] In recent years, due to the mass production, use and improper discharge of mercury and mercury salts, mercury pollution has become one of the major global environmental problems. Mercury in water, soil and the atmosphere is continuously enriched in organisms and human bodies through the food chain, which can damage the central and peripheral nerves, cause Minamata disease, movement disorders, fetal brain damage and other diseases, seriously endangering human survival and health. At present, relatively mature mercury detection technologies are mostly instrumental analysis methods, such as atomic fluorescence spectrometry, electrochemical method, atomic absorption and atomic emission spectrometry, inductivel...

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Problems solved by technology

These methods have good specificity, accuracy and sensitivity, but this type of technology relies on large instruments, complicated sample pretreatment steps, and is not suitable for cheap and fast on-site real-time detection

[0003] In recent years, the application of DNA biosensing technology in the detection of mercury ions has become a hotspot in this field. In 2004, Ono et al. reported for the first time that Hg 2+ Can insert Thymine-Thymine bases to form stable Thymine-Hg 2+ -Thymine (T-Hg 2+ -T) coordination, as Hg 2+ The detection of mercu

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