G- 三链体可视化核酸传感器用于四环素的检测.

Tetracycline is widely used in animal husbandry and aquaculture to prevent bacterial infection and improve growth rate because of its broad-spectrum activity and low cost. Excessive use of tetracycline leads to antibiotic residues in food，which seriously threatens human health. Thiophenin T（ThT）can be embedded into a special nucleic acid structure，so that the fluorescence intensity is strongly excited to achieve signal output. In this paper，tetracycline aptamer can bind with G-rich sequence to form a double chain，but tetracycline preferentially binds with the aptamer when it exists. The G-rich sequence after unbound can fold itself to form a G-triplex structure，which enhances the fluorescence intensity of ThT. According to the good linear relationship between the target concentration and the fluorescence intensity of ThT，the quantitative detection of tetracycline can be acheieved. The method offers good linearity in the range of tetracycline concentration from 1 nmol/L-1 μmol/L 1 μ m，R2 is as high as 0.99，detection limit is 0.07 nmol/L，and detection can be completed within 25 min. Therefore，a visualization method based on G-triplex for double-stranded competitive internal cleavage has been developed and simple， rapid，sensitive，specific and low-cost detection of tetracycline is achieved. [ABSTRACT FROM AUTHOR]