Fabrication of porous silicon-based biosensor

A porous silicon-based biosensor for detection of bacteria was fabricated. Silicon (0.01 ohm-cm, p-type) was anodized electrochemically in a hydrofluoric acid solution containing electrochemical cell using different current and time conditions ranging from 100 mA/cm2 for 30 sec to 2 mA/cm for 1 hr to produce sponge like porous layer of silicon. Anodizing conditions of 5 mA/cm² for 1 hr was best for biosensor fabrication. Porous silicon chips were functionalized using silanization and antibodies immobilized to the porous surface. Chemiluminescence-based assay was used to assess the functionalization of the biosensor. Light emission, for the silanized porous silicon biosensor chip with Salmonella was 10-fold greater than that of the control and non-silanized porous silicon with Salmonella. Higher light emission was observed for porous silanized biosensor with Salmonella compared to that of the non-porous chip. Porous silicon-based biosensor was fabricated and functionalized to successfully detect Salmonella.