Roles of TiO2 in the highly robust Au nanoparticles-TiO2 modified polyaniline electrode towards non-enzymatic sensing of glucose

Abstract

Along with the rise of diabetes mellitus issue, glucose sensor has become an imperative tool for healthcare. Studies have been widely conducted on electrode materials for glucose sensors; metal nanoparticles and/or oxide particles in its nano-size are reported to exhibit remarkable electrocatalytic activities in the non-enzymatic glucose sensors. However, the decoration processes of metal nanoparticles or nano-sized oxides are known to be tedious and time-consuming. In addition, the processes usually result in great amount of waste solution emission. In this study, therefore, an Au nanoparticles (NPs)-TiO2 modified polyaniline (PANI) composite is practiced towards the applications of non-enzymatic glucose sensors, by using a facile and time-saving thermal reduction and by electrodeposition techniques with low waste solution emission. Au NPs, which is modified with TiO2 nanoparticles in its optimized amount, performs the highest electrocatalytic activity to the oxidation of glucose in alkaline solution. The stability of Au NPs-TiO2/PANI is superior to those of most reported results over 70 days. The sensitivity and detection limit are 379.8 μA mM−1 cm−2 and 0.15 μM, respectively. High selectivity of Au NPs-TiO2/PANI is also confirmed by the interference test. Spill-over effect of OH− between Au NPs and TiO2, which is the main reason for the improved catalytic activity, is described in this study.