Photonic crystal based on porous silicon as a biosensor

One-dimensional photonic crystals were fabricated based on porous silicon (PSi) by electrochemical method. These nanostructures consisted of ۲۰ alternating porous layers of low and high porosity. Low porosity (L) layers (high refractive index) have ۶۲% ± ۵% porosity, ۹۰ nm ± ۱۱ nm thickness and refractive index of ۱.۵۰ ± ۰.۱۴. However, these parameters for high porosity (H) layers (low refractive index) are ۷۵% ± ۳%, ۱۲۵ nm ± ۱۰ nm and ۱.۴۶ ± ۰.۰۷ respectively. To detect human growth hormone (hGH), the photonic crystal surface was oxidized, modified by APTES ((۳- Aminopropyl) triethoxysilane), glutaraldehyde (GA) as biochemical linkers, and then anti-growth hormone antibody (anti-hGH) as biorecepotor. Linear response to hGH inthe range of ۱۰۰ ng/ml-۵۰۰ ng/ml in PBS buffer was obtained.