Au-loaded  ZnO  hollow nanospheres have been successfully synthesized by using  carbon nanospheres as sacrificial templates. This simple strategy could be expected to be extended for the fabrication of similar metal– oxide  loaded hollow nanospheres using different precursors. The structural and morphological characteristics of the resultant product were investigated by  X-ray diffraction  ( XRD ),  transmission electron microscopy  ( TEM ),  scanning electron microscopy  ( SEM ), and  high-resolution transmission electron microscopy  ( HRTEM ). The hollow nanospheres are porous, with the diameters ranging from 220 to 280 nm. To demonstrate the usage of such Au-loaded  ZnO  nanomaterial, a chemical gas sensor has been fabricated and investigated for  NH ₃  detection. The Au-loaded  ZnO  sensor exhibits excellent sensing performances compared with hollow  ZnO  and compact  ZnO  sensors. The dynamic transients of the Au-loaded  ZnO  sensors demonstrated both their fast response (0.8–1.5 s) and recovery (3–4 s) towards  NH ₃  gases. The combination of  ZnO  hollow structure and catalytic activity  of  Au  loaded gives a very attractive sensing behavior for applications as real-time monitoring gas sensors with fast responding and recovering speed.