Nanocrystalline SnO2, In2O3 and In2O3–SnO2 thin films have been prepared by modified sol–gel methods making use of no-standard precursors and a suitable surfactant. The oxide thin films have been used as gas-sensing layers in chemoresistive gas sensors and their performances in the detection of nitrogen dioxide (2–20ppm in dry air) have been analysed by electrical characterization in controlled atmosphere. The samples have been structurally and morphologically characterized by X-ray diffraction and SEM, respectively. Good gas …