Micro-arrayed cellular chips with optical sensor membranes for pH and oxygen

We are developing micro-well array chip which has a quarter million wells on one chip, and diameter of each well is 10 /spl mu/m and only one cell can be occupied for each well. In this paper, we prepared optical pH and oxygen sensors in each well for monitoring of cell activity. Fluorescein isothiocyanate (FITC) and Tris(1,10-phenanthroline)ruthenium (II) chloride (Ru complex) was used as pH and oxygen sensing indicators respectively. Polydimethylsiloxane (PDMS) film which has 10 /spl mu/m diameter holes was put onto a silicide glass (DNA chip grade). In case of the pH sensor array, the amine-group introduced slide glass was used and FITC was covalently bound to the glass surface. In case of oxygen sensor array, the slide glass was coated with the Nafion containing Ru complex. Fluorescence intensity of each well was measured by using a high resolution microarray scanner.