Abstract This paper reviews the process of growing large area arrays of carbon nanotubes (CNT) to be used as sensing platforms. First the work explores different methods to prepare Ni catalyst particles. More precisely, the work shows how the nanostructured arrays of catalyst are obtained by thermal annealing of Ni thin films, laser nanostructuring of Ni thin films and formation by organic dendrimers in aqueous solution. The growth process by chemical vapour deposition (CVD) is detailed and the influence of the catalyst particles on the final morphology of the tubes is discussed. A discussion of the advantages and disadvantages of each Ni nanoparticle technique to grow CNT arrays as a sensing platform is presented.