A supramolecular electrochemical probe based on a tetrazole derivative pillar[5]arene/methylene blue system

Abstract

For the first time, an original synthetic approach has been developed that enables the introduce ten tetrazole fragments into the pillar[5]arene structure. A supramolecular electrochemical probe was assembled for the first time from the obtained macrocycles and an electrochemically active signal converter: methylene blue (MB) dye. The ability of pillar[5]arene containing tetrazole fragments to selectively bind MB was confirmed by UV–vis and 2D ¹H–¹H NOESY spectroscopy. The stoichiometry of the resulting pillar[5]arene/MB complex = 1 : 2. This new supramolecular probe pillar[5]arene/MB allowed the detection of changes in the electrochemical signals of MB implemented in the supramolecular complex depending on the presence or absence of some metal ions (Zn²⁺ and Co²⁺) that do not exert their own redox activity. This will find further applications for the enhancement of the range of analytes detected by their influence on host–guest complexation and for the design of biosensors based on specific DNA–MB interactions.