Trichloro(octyl)silane (OTS) is a linear alkylsilane which is used as a modifying agent which creates a low cost hydrophobic surface with high thermo-mechanical stability. OTS contains hydrolysable groups which form a covalent bond with the hydroxyl groups present on the surface.

OTS functionalized magnesium oxide (MnO₂)/aluminium oxide (Al₂O₃) surface can be used as a catalyst in the decomposition of ozone (O₃) and nitrogen dioxide (NO₂). OTS can also be used for the surface modification of silicon oxide (SiO₂), used in the fabrication of pentacene organic field effect transistors (OFETs). OTS functionalized wafers can be coated on enhanced green fluorescent protein (GFP) and anchor peptides based films to determine the thickness of the films.