Feasibility of an Optical Biosensor Based on Porous Silicon

G. Di Francia¹, L. Quercia¹, S. La Ferrara¹, S. Manzo¹, S. Chiavarini²,

F. Cerullo³, F. De Filippo³, V. La Ferrara³, P. Maddalena³, R. Vitiello³

¹CR ENEA Portici, Localita’ Granatello, 80055 Portici, Italy

²CR ENEA Casaccia, Via Anguillarese, 00060 Roma, Italy

³INFM and Dipartimento di Scienze Fisiche, Monte Sant’Angelo, 80100 Napoli, Italy

Porous Silicon thin films, obtained by p-type silicon, have been used for developing an optical interferometric biosensor. Its surface has been modified using a bromine oxidation to prepare porous silicon for DNA attachment. Optical characterization has been made either for as prepared samples and for oxidized ones. Modelling shows that large reflectance variations can be expected when such a treated PS surface is exposed to even small quantities of DNA.