Lithographic Structures with Attached Antibodies for Columnar Immunosensors

Columnar biosensors are a new type of electromechanical sensors which can be mass produced, allow easy quantification of the sensor signal, and have a relatively high Q factor. To use these columns for biosensing purposes, the column caps have to be coated selectively with antibodies which act as a receptor layer. Here two different coating strategies are shown: In the first case, the wafer surface was photolithographically structured in such a way, that the column caps were coated with a protein-adherent layer. In the second approach, the whole surface except the column caps was coated with a protein-repellent layer. After coating the column cap surfaces in a subsequent step with anti-A antibodies, selective attachment of erythrocytes of blood group A was observed.