Silicon based affinity biochips viewed with imaging ellipsometry

In this paper we report on the fabrication of an affinity biochip with a ma trix of 900 targets for detection with imaging ellipsometry. Two methods of fabrication of chips are shown: one based on wet etching of a silicon surf ace and the other on the preparation of so-called tension wells on the sili con surface. The dispensing of reagents and ligands was performed using a p ipetting robot equipped with a micro-capillary, a syringe pump and micro-st epping motors. Measurements were performed on the chips in real time with c arbohydrate model substances selected for six common lectins. Affinity bind ing was shown for three of the tested model substances.