Characterization of nanoporous silicon-based DNA biosensor for the detection of Salmonella enteritidis

Abstract

A biosensor for the detection of food-borne pathogens (Salmonella Enteritidis) was fabricated based on nanoporous silicon (NPS). P-type silicon wafers (100, 0.01 Ω cm) were anodized electrochemically in an electrochemical Teflon cell, containing ethanoic hydrofluoric acid solution to produce the porous layer on the silicon surface. The porous silicon surface was functionalized with DNA probes specific to the insertion element (Iel) gene of Salmonella Enteritidis. A biotin-streptavidin system was utilized to characterize the availability of the nanopores and the specificity of the DNA probe. Based on the electrical property of DNA, redox indicators and cyclic voltammetry were used for the characterization of the biosensor. Results showed that the DNA probe was specific to the target DNA, and the porous silicon-based biosensor had more active surface area and higher sensitivity (1 ng/mL) than the planar silicon-based biosensor. This simple, label-free porous silicon-based biosensor has potential applications in high-throughput detection of pathogens. © 2008 IEEE.