Line width dependence on glucose detection characteristics of poly-silicon wire (PSW) sensors with a surface modified by polydimethylsiloxane-treated silica nanoparticles (NPs)

Abstract

This study investigates the line width dependence on glucose analyst characteristics of PSW with a surface modified by 3-aminopropyltriethoxysilane mixed with polydimethylsiloxane-treated hydrophobic fumed silica NPs plus ultra-violet illumination (γ-APTES+NPs+UV). It is found that the sensitivity increases as the PSW line width decreases. The improvement in sensitivity due to UV illumination tends to saturate at exposure time 120 s, which is independent of line width. The channel current density change ΔJ versus surface to volume ratio of the PSW with different line-widths showed linear behavior for all of the coated membranes. The interference immunity tends to rise as the line width increases. For a 500 nm wide PSW, the disturbance caused by acetaminophen (AP) interference can be kept below 3.5% of the original sensing current density for AP-to-glucose concentration ratios up to 600∶1 if the surface is modified with γ-APTES+NPs+UV.