Method for detecting lead ions by forming G-quadruplex quenching fluorescent light by using functional nucleic acid

Abstract

The invention relates to a method for detecting lead ions by forming G-quadruplex quenching fluorescent light by using functional nucleic acid, belonging to the technical field of water quality detection. The method comprises the following steps of: marking the functional nucleic acid by using carboxy fluorescein to construct a lead ion detection system, wherein when lead ions are added into the detection system, the lead ions promote the functional nucleic acid to form a G-quadruplex structure to cause fluorescence signals of the whole system to significantly change around 520nm, and the change of the fluorescence signals is in a positive relationship with the concentration of the lead ions; then carrying out fluorescence spectrum scanning by adopting a fluorescent photometer to obtain a fluorescence quenching rate standard curve; and mixing a water sample to be tested and ultrapure water, namely contrast samples, with a mother solution of the functional nucleic acid respectively, and comparing the fluorescence quenching rates of two mixed products at a part of which the wavelength is 480nm with the fluorescent quenching rate standard curve to obtain the concentration of the lead ions in the water sample to be tested. By adopting the method, the defects that a lot of assistants are needed to be introduced during the detection of the lead ions by using the existing functional nucleic acid, a complex catalytic reaction is related and the like are overcome, and efficient water body lead ion detection of which the lowest detection limit is 0.77ppb and the cost is low is realized by adopting simple operation.

Description

technical field [0001] The invention relates to a method in the technical field of lead detection in water bodies, in particular to a method for detecting lead ions by using functional nucleic acid to form a G-quadruplex to quench fluorescence. Background technique [0002] As one of the most common heavy metal pollutants, lead ion has attracted worldwide attention due to its high toxicity and harm to the environment and human beings. Lead ions in the environment are persistent, easy to migrate and highly bioaccumulative. 90% of the lead entering the human body is stored in the bones, and 10% is distributed to the organs and tissues of the whole body with the blood, affecting the functions of the brain, kidney, nervous system and red blood cells, etc., especially after infants absorb lead, more than 30% will be retained In the body, it affects the growth and intellectual development of infants and young children, and damages their cognitive function, neurobehavior, learning...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above-mentioned deficiencies in the prior art, the present invention proposes a method for using functional nucleic acid to form a G-quadruplex to quench fluorescence and detect lead ions, which overcomes the need to introduce many auxiliary substances and involve complex procedures for the detection of lead ions by existing functional nucleic acids. Defects such as catalytic reactions, using simple operations to achieve a minimum detection limit of 0.77ppb, low-cost and efficient detection of lead ions in water

Images