A sensing chip including a substrate, a plurality of metal nanostructures, a first surface modified layer and a second surface modified layer is provided. The metal nanostructures are disposed on the substrate. The first surface modified layer is disposed on a surface of the metal nanostructures, wherein the first surface modified layer includes a plurality of thiol group-containing molecules. The second surface modified layer is disposed on a surface of the substrate, wherein the second surface modified layer includes a plurality of silyl group-containing molecules.