TY - JOUR
T1 - Nanostructured porous si optical biosensors
T2 - Effect of thermal oxidation on their performance and properties
AU - Shtenberg, Giorgi
AU - Massad-Ivanir, Naama
AU - Fruk, Ljiljana
AU - Segal, Ester
N1 - Publisher Copyright: © 2014 American Chemical Society.
PY - 2014/9/24
Y1 - 2014/9/24
N2 - The influence of thermal oxidation conditions on the performance of porous Si optical biosensors used for labelfree and real-time monitoring of enzymatic activity is studied. We compare three oxidation temperatures (400, 600, and 800 °C) and their effect on the enzyme immobilization efficiency and the intrinsic stability of the resulting oxidized porous Si (PSiO2), Fabry-Pérot thin films. Importantly, we show that the thermal oxidation profoundly affects the biosensing performance in terms of greater optical sensitivity, by monitoring the catalytic activity of horseradish peroxidase and trypsinimmobilized PSiO2. Despite the significant decrease in porous volume and specific surface area (confirmed by nitrogen gas adsorption-desorption studies) with elevating the oxidation temperature, higher content and surface coverage of the immobilized enzymes is attained. This in turn leads to greater optical stability and sensitivity of PSiO2 nanostructures. Specifically, films produced at 800 °C exhibit stable optical readout in aqueous buffers combined with superior biosensing performance. Thus, by proper control of the oxide layer formation, we can eliminate the aging effect, thus achieving efficient immobilization of different biomolecules, optical signal stability, and sensitivity.
AB - The influence of thermal oxidation conditions on the performance of porous Si optical biosensors used for labelfree and real-time monitoring of enzymatic activity is studied. We compare three oxidation temperatures (400, 600, and 800 °C) and their effect on the enzyme immobilization efficiency and the intrinsic stability of the resulting oxidized porous Si (PSiO2), Fabry-Pérot thin films. Importantly, we show that the thermal oxidation profoundly affects the biosensing performance in terms of greater optical sensitivity, by monitoring the catalytic activity of horseradish peroxidase and trypsinimmobilized PSiO2. Despite the significant decrease in porous volume and specific surface area (confirmed by nitrogen gas adsorption-desorption studies) with elevating the oxidation temperature, higher content and surface coverage of the immobilized enzymes is attained. This in turn leads to greater optical stability and sensitivity of PSiO2 nanostructures. Specifically, films produced at 800 °C exhibit stable optical readout in aqueous buffers combined with superior biosensing performance. Thus, by proper control of the oxide layer formation, we can eliminate the aging effect, thus achieving efficient immobilization of different biomolecules, optical signal stability, and sensitivity.
KW - Biosensor
KW - Enzyme
KW - Label free
KW - Nanostructure
KW - Porous Si
KW - Thermal oxidation
UR - http://www.scopus.com/inward/record.url?scp=84912022943&partnerID=8YFLogxK
U2 - https://doi.org/10.1021/am503987j
DO - https://doi.org/10.1021/am503987j
M3 - مقالة
SN - 1944-8244
VL - 6
SP - 16049
EP - 16055
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 18
ER -