Fabrication of silicon nanowire networks for biological sensing

In this paper, we present the elaboration procedure of a new silicon nanowire-based DNA biosensor, which provides promising detection capacity. On the one hand, we report for the first time the fabrication of random networks based on silicon nanowires by the filtration method. The so-fabricated networks are reproducible and homogeneous, the nanowire density is easily monitored. These networks can be deposited at room temperature over large areas on various types of substrates: rigid or flexible, conductive or insulating, transparent or opaque. On the other hand, by adapting a process for the immobilization of DNA onto the silicon nanowire networks, we demonstrate the possibility to use such material for the detection of DNA hybridization. The fluorescence study evidences a good selectivity and an enhanced sensitivity of the nanowires.