%0 Journal Article
%T Gamma-Ray Sterilization Effects in Silica Nanoparticles/¦Ã-APTES Nanocomposite-Based pH-Sensitive Polysilicon Wire Sensors
%A Jing-Jenn Lin
%A Po-Yen Hsu
%J Sensors
%D 2011
%I MDPI AG
%R 10.3390/s110908769
%X In this paper, we report the ¦Ã-ray sterilization effects in pH-sensitive polysilicon wire (PSW) sensors using a mixture of 3-aminopropyltriethoxysilane (¦Ã-APTES) and polydimethylsiloxane (PDMS)-treated hydrophobic fumed silica nanoparticles (NPs) as a sensing membrane. pH analyses showed that the ¦Ã-ray irradiation-induced sensitivity degradation of the PSW pH sensor covered with ¦Ã-APTES/silica NPs nanocomposite (¦Ã-APTES+NPs) could be restored to a condition even better than prior to ¦Ã-ray irradiation by 40-min of post-sterilization room-temperature UV annealing. We found that the trapping charges caused by ¦Ã-ray sterilization primarily concentrated in the native oxide layer for the pH sensor covered with ¦Ã-APTES, but accumulated in the ¦Ã-APTES+NPs layer for the ¦Ã-APTES+NPs-covered sensor. It is believed that mixing the PDMS-treated silica NPs into g-APTES provides many g-APTES/SiO2 interfaces for the accumulation of trapping charges and for post-sterilization UV oxidation, thus restoring ¦Ã-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 ¦Ã-ray and UV irradiations. This investigation suggests ¦Ã-ray irradiation could be used as a highly-efficient sterilization method for ¦Ã-APTES-based pH-sensitive biosensors.
%K 3-aminopropyltriethoxysilane
%K polydimethylsiloxane
%K silica nanoparticles
%K ¦Ã-ray sterilization
%K post-sterilization UV annealing
%U http://www.mdpi.com/1424-8220/11/9/8769