Sub-ppb detection of acetone using Au-modified flower-like hierarchical ZnO structures

Flower-like hierarchical ZnO structures assembled by porous single-crystalline nanosheets were firstly synthesized by a one-pot wet-chemical method followed by an annealing treatment. Then, polyethylenimine (PEI) was used to modify the flower-like hierarchical ZnO structures followed by anchoring Au nanoparticles (NPs) on their surface through electrostatic interactions. The Au-modified flower-like hierarchical ZnO structures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectrum (EDS). It can be found that Au NPs with a mean diameter of 12 nm was uniformly modified on the surface of the porous single-crystalline ZnO nanosheets. The as-prepared products exhibited a good response to acetone with a linear range of 0.5-100 ppb under the optimized operating temperature of 300 degrees C. The lowest detection concentration was 0.5 ppb, which is the lowest detection limit to our knowledge. (C) 2015 Elsevier B.V. All rights reserved.