The Si-wafers were pre-cleaned in an ultrasonic bath in acetone for 10 min and rinsed with isopropanol. Plasma treatment was applied on the Sisubstrate for 5 min at 20 mW (Diener, Ebhausen, Germany) to remove organic contaminants. GMO and HEA were mixed and homogenized by heating to 50 °C and vortexing. The samples were diluted in ethanol to a concentration of 10 mg ml -1 (1% w/v), and 5 µl of the solution was drop-casted on the Si-wafers. Before complete ethanol evaporation, the Si-wafers were rapidly immersed in excess water for a few seconds to acquire a smooth and uniform coating on the surface. Before further experiments, the samples were left for at least 2 hours to ensure ethanol evaporation.