A portable drug testing device for handheldly collecting a sample from exhaled breath of a subject for further sensor based analysis. The portable drug testing device comprising a housing comprising at least one inlet and at least one outlet for the exhaled breath to exit through, and a sampling membrane arranged in the housing. a tubular element having a mouthpiece section for the subject to exhale into, and a selective trap section in fluid communication with the mouthpiece and the inlet of the housing having a non-straight gas flow path for letting aerosols pass through the tubular element. The sampling membrane is arranged to collect the aerosols from the exhaled breath. The portable drug testing device further comprises a volume measure unit for determining that a pre-defined volume of the exhaled breath has passed through the sampling membrane.
