Synthesis, characterization and computational study of the conjugated thiol-systems for self-assembled monolayers on gold electrode

In the present work, we examine the synthesis and characterization of the pi-conjugated organic molecules applied to immobilize the laccase enzyme on gold electrode surfaces. The density functional theory (DFT) and time-dependent (TD-DFT) were performed to compute the optoelectronic properties. The interactions between the ligand (conjugated thiol system) and the receptor (laccase enzyme) were investigated using docking simulations. The pi-conjugated systems were prepared by the Horner-Wadsworth-Emmons reaction. These conjugated organic molecules were further used to design a new generation of nanostructured bioelectrodes that allow the electrical connection of a laccase enzyme with the gold metallic surface. Direct electron transfer (DET) between the enzyme (laccase) and the gold electrode was achieved in a potentially straightforward manner. This modified cathode could be implemented in new biosensors to assess the concentration of particular analytes, such as the effective detection of O2 for healthcare monitoring and disease diagnosis. It could also be employed to develop promising biofuel cells.