Exhaled acetone is one of the representative biomarkers for the noninvasive diagnosis of type-1 diabetes. In this work, we have applied a facile two-step chemical bath deposition method for acetone sensors based on α-Fe2O3/SnO2 hybrid nanoarrays (HNAs), where one-dimensional (1D) FeOOH nanorods are in situ grown on the prefabricated 2D SnO2 nanosheets for on-chip construction of 1D/2D HNAs. After annealing in air, ultrafine α-Fe2O3 nanorods are homogenously distributed on the surface of SnO2 nanosheet arrays (NSAs). Gas sensing results show that the α-Fe2O3/SnO2 HNAs exhibit a greatly enhanced response to acetone (3.25 at 0.4 ppm) at a sub-ppm level compared with those based on pure SnO2 NSAs (1.16 at 0.4 ppm) and pure α-Fe2O3 nanorods (1.03 at 0.4 ppm), at an operating temperature of 340°C. The enhanced acetone sensing performance may be attributed to the formation of α-Fe2O3–SnO2 n-n heterostructure with 1D/2D hybrid architectures. Moreover, the α-Fe2O3/SnO2 HNAs also possess good reproducibility and selectivity toward acetone vapor, suggesting its potential application in breath acetone analysis.
Graphene chemiresistors modified with functionalized triphenylene for highly sensitive and selective detection of dimethyl methylphosphonate