An Enhanced Performance of Glucose Biosensor Based on TiO₂ Nanorod Arrays Decorated with Ag Nanoparticles

In this study, TiO2 nanorod arrays (NAs) on carbon paper (CP) substrates were prepared via hydrothermal synthesis. Then, Ag nanoparticles (NPs) were deposited on the surface of the TiO2 NAs to enhance the electrocatalytic activity and analysis ability of the electrode for H2O2. Thereafter, GOx was modified on the surface of the Ag NPs-TiO2 NAs/CP via the cross-linking method for the detection of glucose. The GOx/Ag NPs-TiO2 NAs/CP integrates the functions of the specific recognition of glucose, signal transduction, and signal amplification. In an in vitro test, this GOx/Ag NPs-TiO2 NAs/CP biosensor shows a sensitivity of 0.182 mA mM(-1)cm(-2) , which is 6.6-fold that for the GOx/CP sensor (0.0276 mA mM(-1) cm(-2)). The sensor can transduce the GOx-catalyzed reaction into significant current signals within 5 s. The relationship between the glucose concentration and the sensitivity to glucose is linear with the correlation coefficient R-2 of 0.9996 in the range of 0-0.9 mM, and the detection limit was estimated to be 1.6 mu M.