Study of low noise high throughput microchip device for electrochemical measurement from single cells

Abstract

We are developing transparent multi- electrochemical electrode arrays on microchips in order to automate measurement of quantal exocytosis of oxidizable transmitter from individual vesicles. In order to achieve low noise recording, I measured the current noise power spectral density (SI) to understand the physical basis of dominant noise sources. My results demonstrate that microchip electrodes have a noise performance that is comparable, and in some cases superior, to that of “gold standard” carbon-fiber microelectrodes. Whereas patterning hundreds of electrodes in a small area is straightforward using photolithography, easily making connections between hundreds of electrodes and external amplifiers remains a bottleneck. Here I report a multiplexing approach using multiple fluidic compartments that can reduce the number of external connections by ~100-fold. Measurements demonstrate that it attains current noise levels as low as that obtained with individual electrodes. The new device will enable high-throughput measurements combined with fluorescence microscopy.