Heterogenous surface functionalization

A method for detecting at least a chemical and/or biological interaction, the method comprising:

• providing a microcarrier comprising:
• at least a detection surface for performing an assay of a composition flowing in a microchannel, said composition comprising at least one target molecule, wherein said detection surface comprises:
• a first area functionalized with a first functional group for providing a first signal indicative of (i) a specific chemical and/or biological interaction of the composition with the first area, together with (ii) a non-specific chemical and/or biological interaction of said composition with said first area,
• wherein the first area is functionalized with the first functional group for detecting said at least one target molecule of the composition, and
• a second area providing a second signal different from the first signal, said second signal being emitted during the assay and being indicative of said non-specific chemical and/or biological interaction occurring in the first area,
• wherein the second area is functionalized for detecting the non-specific chemical and/or biological interaction between said at least one target molecule of the composition and the detection surface,
• wherein information about the presence of said specific chemical and/or biological interaction is provided by a comparison of the first signal and the second signal, and
• wherein the first signal and the second signal result from a same environment with regard to said composition, and are thereby directly comparable;
• contacting said microcarrier with a composition providing at least (i) a specific chemical and/or biological interaction and (ii) a non-specific chemical and/or biological interaction with the first area and (iii) said non-specific chemical and/or biological interaction with the second area;
• measuring the first signal emitted by the first area and the second signal emitted by the second area;
• and
• qualifying the presence of said specific chemical and/or biological interaction on the first area by a differential analysis between the first signal and the second signal.