Effect of magnetism on the ethanol sensitivity of undoped and Mn-doped CuO nanoflakes

► CuO nanoflakes show room temperature ferromagnetism (RTFM) due to surface defects. ► Mn doping in CuO induces cluster formation on the surface, which destroys RTFM. ► CuO nanoflakes show more ethanol sensitivity compared to Mn-doped CuO nanoflakes. ► The surface has significant influence on both magnetism and ethanol sensitivity. ► Relation between magnetism and sensing mechanism is rarely reported in literature.