Supramolecular assembly of pyrene-tetrathiafulvalene hybrids on graphene: structure-property relationships and biosensing activity

Two different molecular receptors ( 1 and 2 ) incorporating one and three pyrene units to promote the π-π interaction with the basal plane of graphene are reported. In order to modulate the electronic properties of graphene, the new receptors are endowed with an electron-donor tetrathiafulvalene moiety (exTTF). The resulting non-covalent hybrids have been characterized by different analytical, spectroscopic and microscopic techniques (TGA, Raman, UV-Vis absorption, TEM and XPS), and the supramolecular interaction of the molecular systems with graphene has been investigated by theoretical calculations. The electrochemical behavior of the pyrene-exTTF hybrids onto distinct graphene-based materials allowed us to determine the differences between both receptors and their affinity for various surfaces. Finally, the non-covalent hybrid formed by a pyrene unit and exTTF has been used for the development of an enzymatic biosensor able to operate at very low potentials. The supramolecular functionalization of graphene with monopodal and tripodal pyrene receptors bearing a π-extended tetrathiafulvalene is investigated, and used to develop graphene-based electrodes for enzyme-based hydrogen peroxide sensing.