Highly porous magnesium ferrite powders were synthesized by one step method with variation in fuel to oxidizer ratio. Magnesium nitrate and ferric nitrate were used as oxidizers and glycine was used as fuel to carry out auto-combustion synthesis. The structural and morphological properties of the resulting materials were studied using XRD, BET, TEM, SEM and EDAX techniques. The as prepared samples show the formation of sponge-like materials. The XRD measurements confirm the single phase spinel-type magnesium ferrite formation. The excess amount of glycine leads to increase in both degree of crystallinity and lattice parameter. Enhancement in magnetization takes place with increase in G/N ratio. Response to liquid petroleum gas (LPG) was studied on MgFe 2 O 4 nano-particles by varying fuel to oxidizer (G/N) ratio.