S. Wakamatsu, T. Ohara, and I. Uno, Atmos. Environ, vol.30, pp.715-721, 1995.

, Air Quality Guideline for Europe, EURO, World Health Organization, Regional, Copenhagen, European Series, 1998.

G. J. Cadena, J. Riu, and F. X. Rius, Analyst, vol.132, pp.1083-1099, 2007.

M. Acuautla, S. Bernardini, and M. Bendahan, Key Engineering Materials, vol.605, pp.163-166, 2014.

D. Y. Kim, J.Y. Son. Solid-State Lett, vol.12, pp.109-111, 2009.

L. F. Silva, J. -c.-m'pekob, and A. C. Catto, Sensors and Actuators B Chemical, vol.240, pp.573-579, 2016.

M. Gaceur, S. Ben-dkhil, and D. Duché, Funct. Mat, vol.26, pp.243-253, 2016.

A. K. Diallo, M. Gaceur, and S. Fall, Materials Science and Engineering: B, vol.214, pp.11-18, 2016.