Silicon nanowires as acetone-adsorptive media for diabetes diagnosis

Abstract

Early detection of diabetes, a worldwide health issue, is key for its successful treatment. Acetone is a marker of diabetes, and efficient, non-invasive detection can be achieved with the use of nanotechnology. In this paper we investigate the effect of acetone adsorption on the electronic properties of silicon nanowires (SiNWs) by means of density functional theory. We considered hydrogenated SiNWs grown along the [111] bulk Si axis, with group-III impurities (B, Al, Ga), for which both surface substitutional doping and functionalizing schemes are considered. We present an analysis of the adsorption configuration, energetics, and electronic properties of the undoped and doped SiNWs. Upon acetone adsorption, the SiNW without impurities becomes an n-type semiconductor, while most substituted/functionalized cases have their HOMO-LUMO gap tuned, which could be harnessed in optical sensors. Acetone is always chemisorbed, although for the case without impurities, and the Al- and Ga-functionalization schemes, the chemisorption is very weak. These nanostructures could be used for acetone capture and detection, which could lead to applications in the medical treatment of diabetes.