Nickel oxide-deposited cellulose/CNT composite electrode for non-enzymatic urea detection

Abstract

A highly sensitive non-enzymatic urea sensor was fabricated using nickel oxide deposited on a cellulose/carbon nanotube (CNT) composite. The structure and morphological properties of the NiO/cellulose/CNT composite were investigated using X-ray diffraction and scanning electron microscopy. A thin film of the NiO/cellulose/CNT composite was coated on an indium tin oxide glass to fabricate an amperometric urea sensor. The composition of the modified electrode and detection conditions (i.e., pH and temperature) were optimized. The prepared electrode exhibited an excellent sensitivity of 371 mu A mM(-1) cm(-2) with a fast response time of 4 s. The electrode also showed high stability with only a 3.6% decrease in its sensitivity after storage for two months under ambient conditions. In addition, the feasibility for urea analysis in urine samples was demonstrated. (C) 2016 Elsevier B.V. All rights reserved.