Disclosed herein are methods for functionalizing metal oxides, including tin dioxide. The methods comprise contacting at least one linker precursor comprising a first functional group to a metal oxide and exposing the linker precursor to UV light. The first functional group covalently binds to the metal oxide via a UV light induced reaction. The linker precursor may be an alkene having a vinyl group or an alkyne having an ethynyl group. Other molecules, such as biomolecules and dye molecules, may be bound to the linker precursors. The functionalized metal oxides may be used alone or as coatings on a substrate and find use in a variety of devices, including biosensors and dye sensitized solar cells.