A cargo inspection apparatus for the inspection of an analyte carried by a medium is disclosed. The apparatus includes a housing having an inlet allowing for entry of the medium and an outlet allowing for exit of the medium, and an adsorber disposed within the housing in fluid communication with the medium flow from the inlet to the outlet, the adsorber includes a substrate having disposed thereon a nanoparticle film. The nanoparticle film has nanoparticles having an average particle size of equal to or less than about 500 nanometers.