Development of electrical biosensors based on nanostructured porous silicon

Nanostructured porous silicon (nanoPS) can be described as a network of silicon crystals with sizes in the range of a few nanometers. The typical large specific surface area and high reactivity of nanoPS make this material very suitable for many different applications in the field of sensing. Moreover, its biocompatibility and biodegradability opens the way to the development of biosensors. Within this context, in the present work the use of nanoPS in the field of electrical biosensing is explored. More specifically, nanoPS-based devices with the structure Al/nanoPS/silicon/Al and AuNiCr/nanoPS/silicon/Al were fabricated for the electrical detection of glucose and the bacteria Escherichia Coli. The experimental results show that the current-voltage characteristics of the metal/nanoPS/silicon/metal structures show a strong dependence on the presence/absence and surface concentration of glucose and the bacteria Escherichia Coli. The present work describes our findings in the correlation between surface concentration of glucose and bacteria E. Coli and current for a given voltage.