Cell detection using a CMOS image sensor with modified pixel structure suitable for bio-chemical surface activation

This paper presents a CMOS image sensor with a 32 × 32 pixel array suitable for cell capture, detection, and quantification. Pixels measuring 15 μm × 15 μm have a modified structure, suitable for post-CMOS electroless gold plating, which enables surface activation for cell capture without the need for any intermediate layer. This structure also increases the detection probability of captured cells as opposed to non-captured ones, owing to a special light mask (metal shield) implemented on pixels. The light mask enables detection of cells as small as 3 μm in diameter despite the larger pixel size. The proof of concept is demonstrated in this work by imaging yeast cells adsorbed on the sensor surface.