Sensing surfaces capable of selective biomolecular interactions, to be used in biosensor systems

A sensing element suitable for use in a biosensor, comprising:

• a substrate;
• a film of a free electron metal selected from the group consisting of copper, silver, aluminum and gold disposed on said substrate, said film having a first and second major surface, said first major surface being in contact with said substrate;
• and
• a densely packed monolayer of an organic molecule X-R-Y coated on said second major surface of said film where X is a group selected from the group consisting of
• asymmetrical or symmetrical disulfide (-SSR'Y', -SSRY), sulfide (-SR'Y', -SRY), diselenide (-SeSeR'Y', -SeSeRY), selenide (SeR'Y', -SeRY),
• thiol (-SH), isonitrile, nitro (-NO.sub.2), selenol (-SeH), trivalent phosphorus compounds, isothiocyanate, xanthate, thiocarbamate, phosphine,
• thio acid and dithio acid (-COSH, -CSSH),
• where R and R' hydrocarbon chains, optionally interrupted by hetero atoms, of a length exceeding 10 atoms, wherein in the case of an asymmetrical molecule R' or R may be H, and Y and Y' are active groups for covalently binding ligands or a biocompatible porous matrix.

A sensing surface suitable for use in a biosensor comprising:

• a film, having two faces, of a free electron metal selected from the group consisting of copper, silver, aluminum and gold;
• and a monolayer of an organic molecule X-R-Y coated on one of the faces of said film where X is a group selected from the group consisting of
• asymmetrical or symmetrical disulfide (-SSR'Y', -SSRY), sulfide (-SR'Y', -SRY), diselenide (-SeSeR'Y', -SeSeRY), selenide (SeR'Y', -SeRY),
• thiol (-SH), isonitrile, nitro (-NO.sub.2), selenol (SeH), trivalent phosphorous compounds isothiocyanate, xanthate, thiocarbamate, phosphine,
• thio acid and dithio acid (-COSH, -CSSH)
• where R and R' are hydrogen chains, optionally interrupted by hetero atoms, of a length exceeding 10 atoms, wherein in the case of an asymmetrical molecule, R' or R may be H, Y and Y' are active groups for covalently binding ligands or a biocompatible porous matrix.