Downscaling aspects of a conductivity detector for application in on-chip capillary electrophoresis

We are presenting the experimental results of capacitively coupled 2- and 4-electrode conductivity detector fabricated as a glass dip-stick. These results are used as a starting point for investigating the consequences of downscaling the device for on-chip capillary electrophoresis (CE) applications, where the detector is located in a separation microchannel. Our studies show that, it is possible to do accurate and sensitive conductivity sensing in a 150μm wide channel, by making use of 4-electrode set-up with silicon carbide (SiC) thin insulating layers on top of the electrodes.