A sensing method for a nanostructure pixel sensor includes shining light from an incident angle onto a nanostructure pixel sensor; capturing an image of nanostructure pixels of the nanostructure pixel sensor; obtaining brightness values of the nanostructure pixels from the image; and determining a presence and/or amount of an analyte based on an image pattern. The nanostructure pixel sensor includes a plurality of the nanostructure pixels. Each of the nanostructure pixels includes periodic nanostructures. At least two nanostructure pixels have different periodic spacings, and the analyte is applied on the nanostructure pixel sensor before capturing the image.