The switch of the DNA tetrahedral tweezers controlled by mercury ions

In this paper, the one-pot method is used to make the four DNA strands complement each other to construct the basic framework for DNA tetrahedral tweezers. To regulate the opening and closing of DNA tetrahedral tweezers, DNA strands with a high amount of T-base sequences is partially complementary to the tetrahedral framework. Hg²⁺ can form T-Hg-T hairpin structures with T-base. When DNA tetrahedral tweezers encounter Hg²⁺, the T-Hg-T structure is formed to shorten the connecting chain, and the tightening force causes the DNA tweezers to change from an open state to a closed state. Conversely, changes in fluorescence intensity due to the structure change can be used to detect the presence of Hg²⁺.