DNA HYBRIDIZATION DETECTION BY A NANOSTRUCTURED SILICON MICROARRAY

The microarray technology has demonstrated a great potential in drug discovery, proteomics research, and medical diagnostics. The key issue is the high throughput of these devices due to the large number of samples that can be simultaneously analyzed in a single parallel experiment. In this work, we propose an optical microarray constituted by hundreds of Porous Silicon (PSi) Bragg mirrors, characterized by a diameter of 200 micron, as functional platform for the detection of biological events. The PSi has emerged as an interesting support due to its morphology characterized by a high specific surface area, which makes it efficient for biomolecules immobilization. The integration of PSi single sensing elements in a microarray was not straightforward; to this aim a proper process, based on different technological steps, was designed. Then, the PSi elements were functionalized with different sequences of DNA probes and the whole chip was placed in a buffer solution containing the complementary DNA single-strands so to induce hybridization. The bio-recognition event was monitored studying the variation in the optical spectra of the Bragg mirrors.