A supramolecular probe of cyanine dye for Pb2+ detection based on the recognition of a G-quadruplex from DNA duplexes

Abstract

Herein, we carried out the supramolecular self-assembly of cyanine dye (MTC) for the transformation between duplex DNA and G-quadruplex (T30695) for the highly selective and sensitive recognition of Pb²⁺ ions via UV-vis spectroscopy. A specific duplex DNA (duplex-a) consisting of a Pb²⁺ aptamer and its part complementary strand was constructed, which could be unwound to single-strand DNA to form a G-quadruplex in the presence of Pb²⁺. The formed G-quadruplex could transform MTC H-aggregates into monomers, resulting in a specific recognition absorption signal.