Micro/nanoparticle detection: An impedimetric microsensor based on CMOS technology

This paper proposes a microsensor designed for the detection of a single microparticle that has potential to be extended to nanoparticles. The complete system, comprised of a sensing microelectrode array, a microelectronic circuit and a microfluidic device, is implemented on a conventional complementary metal oxide semiconductor (CMOS) chip. To establish a Lab-on-Chip system intended for detecting particles by impedance measurement, the microelectrode array is constructed with multiple metal and via layers using a standard 0.18 mum CMOS process. The impedance variations caused by the presence of a particle are detected by a sensing circuit connected with microelectrodes on the same substrate. The system structure and post-processing of the CMOS chip are presented. The finite element method (FEM) simulation and preliminary experiments completed thus far have proved that identifying a single cell or particle is feasible with the system described here. Also presented are some potential micro and nanoscale applications of this chip that go beyond single particle detection that could be investigated in the future.