Optically-active silica nanowires are produced by metal-induced growth on silicon substrates using ion-implantation, with two different strategies employed for their fabrication. The first is based on Er implantation of nanowires produced by a thin-film Pd catalyst layer, and the second employing implanted Er as both the catalyst and dopant. The luminescence properties of the resulting Er-doped silica nanowires are reported and compared with similarly implanted fused silica samples. Comparison shows that the luminescence lifetime of Er is increased by incorporation within the nanowires due to a reduction in the density of available optical states in these structures. Additional details of the synthesis, structure and properties of these functionalised nanowires are also presented.