Cell-enzyme based biosensors

A method for detection of production of a compound by cells, the method comprising:

• providing a biosensor comprising:
• a sensor configured to detect a change in a charge distribution;
• a sensing layer, wherein the sensing layer is situated on the sensor;
• and a surface layer, wherein the surface layer is situated on the sensing layer, and wherein the surface layer comprises a first region that is enzyme-free and adapted for adherent growth of cells and a second region, adjacent to the first region, wherein the second region is configured for attachment of proteins and comprises a bienzyme system, wherein the bienzyme system is adapted for conversion of a compound produced by the cells into a product which generates a signal detectable by the sensor, wherein the first region and the second region are separated from each other but in contact with the sensing layer, and wherein at least one of the first region and the second region comprises a pattern of a plurality of linear elements, and wherein the first region and the second region are configured such that the cells grow exclusively in the first region;
• providing cells, wherein the cells undergo adherent growth on the first region of the sensor, whereby the compound is produced;
• converting, by the bienzyme system of the second region, the compound into the product which generates a change in a charge distribution in the sensing layer;
• and
• detecting the change in the charge distribution by the sensor of the biosensor, whereby production of the compound by the cells is detected.