A Crown-Ether Loop-Derivatized Oligothiophene Doubly Attached on Gold   Surface as Cation-Binding Switchable Molecular Junction
  A crown-ether dithiol quaterthiophene is synthesized for its covalent immobilization by double fixation on gold surface. While the corresponding dithioester precursor exhibits Pb2+ complexation properties in solution as evidenced by UV-vis spectroscopy and cyclic voltammetry, this Pb2+ affinity is still maintained for monolayers of the dithiol on gold. In addition, current-voltage measurements by Eutectic GaIn drop contact on the monolayer show a significant increase (up to 1.6 x 1E3) of the current at low bias after Pb2+ complexation. 
Truong Khoa Tran, Kacem Smaali, Marie Hardouin, Quentin Bricaud,   Maitena Ocafrain, Philippe Blanchard, Stephane Lenfant, S...
cond-mat.mes-hall