High-performance ethanol gas sensor using TiO2 nanostructures K. P. Priyanka, S. C. Vattappalam, S. Sankararaman, K. M. Balakrishna and Thomas Varghese Eur. Phys. J. Plus, 132 7 (2017) 306 Published online: 13 July 2017 DOI: 10.1140/epjp/i2017-11581-x