A biosensor is a device that signals the presence of a target. Aptamers are the « bio » part of biosensors for the detection of any kind of target: small molecules, proteins, cells. Aptamers can be associated with different modalities of signal transduction: fluorescence, colorimetry, electrochemistry, etc. Novaptech aptaswitch-aptakiss combination is of particular interest for the detection and quantification of small molecules.