▎ 摘　　要

In the present paper, gold (Au) nanoparticle decorated vertical grapheme nanosheet (Au-VGN) composites is investigated for understanding the sensing mechanism along with charge transfer mechanism at nanoscale. Au metal nanoparticles on graphene are characterized by Raman spectroscopy and studied using conducting atomic force microscopy (CAFM). The gas sensing measurements are carried out to study the modulations in the elec-tronic and electrochemical properties of the composites. The findings in electrochemical measurements and theoretical calculations of Au-VGN suggest that changes in electrical, electrochemical properties as well as Raman shift is attributed to the charge transfer between Au nanoparticles and graphene. To have an insight knowledge about the charge transfer mechanism, PFM studies are also carried out for these samples and a sig-nificant effect in modifying the electronic structure of Au decorated VGN towards acetone sensing at room temperature is observed. This metal decorated VGN sample shows a pronounced sensitivity of 10 % within 300 s for 150 ppm of acetone.