p-type semiconducting perovskites Sm1-xAxFe1-yByO3 (A=La, Sr, x=0, 10, 20 at%, B=Cr, Co, Mn, y=0, 10, 20 at%) were synthesised via the polyol method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to confirm the structure and morphology of the materials. Thick films of the materials prepared together with surface doped SmFeO3 (with Au, Ce, Ir, Pd, Pt, Rh, Ru) samples were electrically characterised using high throughput impedance spectroscopy (HT-IS). The gas sensing behaviour was tested at temperatures ranging from 200 to 500°C. For La and Cr doping a model describing a correlation between the (M-O) binding energy and the sensing properties was verified.