“…Urease has often been used as the sensitizing material for the fabrication of urea sensors, like thermal (Xie and Danielsson, 1996;Xie et al, 1995;Fulton et al, 1980;Hauser et al, 1995), conductometric (Sheppard et al, 1996;Jdanova et al, 1996;Castillo-Ortega et al, 2005), piezoelectric (Xu et al, 1996;Yang et al, 2007;Yang et al, 2008), optical (Picioreanu et al, 2000;Koncki et al, 2001;Tsai and Doong, 2005), laser (György et al, 2010) and amperometric (Rajesh et al, 2005;Vostiar et al, 2002;Pizzariello et al, 2001;Stredansky et al, 2000) sensors. However, potentiometric 0956-5663/$ -see front matter © 2011 Elsevier B.V. All rights reserved.…”