Detection system for an electronic nose allowing a physicochemical classification of odours and electronic nose comprising such a system

A detection system comprising:

• a substrate having a surface;
• a plurality of receptors configured to produce a detectable signal when the plurality of receptors physiochemically interacts with at least one volatile compound of a plurality of volatile compounds in a gaseous sample;
• three or more sensors having cross-reactivities relative to one or more volatile compounds of the plurality of volatile compounds, each sensor of the three or more sensors comprising a sensitive part disposed on the substrate and functionalised by a receptor of the plurality of receptors and wherein
• each receptor of the plurality of receptors has a formula
• X-(Esp)m-Z wherein
• X is either a functional group for immobilizing a respective receptor onto the surface of the substrate or is a residue of a compound comprising the functional group for immobilizing the respective receptor onto the surface of the substrate,
• m is 0 or 1,
• Esp is a spacer arm, and
• Z is a sequence comprising two or more α-amino acids;
• wherein the three or more sensors comprise a first series of sensors and a second series of sensors wherein the first series of sensors comprises a first sensor comprising a first receptor having a first α-amino acid wherein the first α-amino acid is hydrophilic α-amino acid and a second sensor comprising a second receptor comprising a second α-amino acid wherein the second-amino acid is a hydrophobic α-amino acid;
• and
• the second series of sensors comprises a third sensor comprising a third receptor comprising a third α-amino acid having a first isoelectric point and a fourth sensor comprising a fourth receptor comprising a fourth α-amino acid having a second isoelectric point wherein the first isoelectric point differs from the second isoelectric point by one or more pH units.