title: Gamma-ray sterilization effects in silica nanoparticles/γ-APTES nanocomposite-based pH-sensitive polysilicon wire sensors.
abstract: In this paper, we report the γ-ray sterilization effects in pH-sensitive polysilicon wire (PSW) sensors using a mixture of 3-aminopropyltriethoxysilane (γ-APTES) and polydimethylsiloxane (PDMS)-treated hydrophobic fumed silica nanoparticles (NPs) as a sensing membrane. pH analyses showed that the γ-ray irradiation-induced sensitivity degradation of the PSW pH sensor covered with γ-APTES/silica NPs nanocomposite (γ-APTES+NPs) could be restored to a condition even better than prior to γ-ray irradiation by 40-min of post-sterilization room-temperature UV annealing. We found that the trapping charges caused by γ-ray sterilization primarily concentrated in the native oxide layer for the pH sensor covered with γ-APTES, but accumulated in the γ-APTES+NPs layer for the γ-APTES+NPs-covered sensor. It is believed that mixing the PDMS-treated silica NPs into γ-APTES provides many γ-APTES/SiO(2) interfaces for the accumulation of trapping charges and for post-sterilization UV oxidation, thus restoring γ-ray-induced sensor degradation. The PDMS-treated silica NPs not only enhance the sensitivity of the pH-sensitive PSW sensors but are also able to withstand the two-step sterilization resulting from γ-ray and UV irradiations. This investigation suggests γ-ray irradiation could be used as a highly-efficient sterilization method for γ-APTES-based pH-sensitive biosensors.
authors.affiliation: Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Puli, Nantou, 54561, Taiwan. cclin@ncnu.edu.tw
authors.forename: Jing-Jenn
authors.initials: JJ
authors.lastname: Lin
authors.forename: Po-Yen
authors.initials: PY
authors.lastname: Hsu
mesh_terms: D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles; D010084:Oxidation-Reduction; D012822:Silicon Dioxide; D014466:Ultraviolet Rays
chemical_list: D012822:Silicon Dioxide