Cobalt oxide (Co3O4) is known to follow the spinel structure as (Co2+)[Co23+O4. The high spin Co2+occupies the interstitial sites of tetrahedral (8a) whereas low spin Co3+are known to occupy the interstitial sites of octahedral (16d) of the close-packed face-centered cubic lattice of CoO.Co2O3. The p-type conductivity of the material (CoO.Co2O3) is known to originate from the vacancies of Co in the crystal lattices or/and excess oxygen at interstitial sites. Furthermore, 1D nanostructures of Co3O4 have been investigated over the past decades as an active material for chemical analytes detection owing to its superior catalytic effect together with its excellent stability. This article discusses the state-of-the-art of growth and characterization of Co3O4 1D nanostructures and their functional characterization as chemical/gas sensors.