A MONOLITHIC SENSOR ARRAY OF INDIVIDUALLY ADDRESSABLE MICROELECTRODES

A monolithic single-chip sensor array for measuring chemical and bioch emical parameters has been developed and fabricated in a modified stan dard CMOS process. The array can be used for amperometric or potentiom etric measurements in order to get a concentration-dependent spatial p rofile of the detected analyte. In addition to 400 working electrodes and two reference electrodes, the chip contains integrated read-out am plifiers, digital circuits for addressing the individual components an d test circuits. The on-chip signal processing allows detection of che mical or biochemical analytes without any interference by the external measurement equipment. High electrode impedances and low power consum ption have been achieved by using CMOS technology. Chemical modificati on of the electrodes is possible by applying an external voltage to th e electrodes. In advantage to non-integrated solutions, the system can be used in a wide field of applications, especially for measurements in narrow passages because of the total chip size of only 14 x 14 mm.