Studies on design, fabrication and electrochemical performance of cobalt aluminate modified pencil electrode towards urea detection

Abstract

A simple and environmentally benign solution combustion method has been employed to prepare CoAl2O4 nanoparticles (CoAl2O4 NPs). Powder X-ray diffraction (XRD) data confirms the formation of crystalline CoAl2O4 with cubic crystal structure. TEM result reveals that the size of CoAl2O4 nanoparticles is about 25 nm. The prepared CoAl2O4 NPs are explored as a potential electrode modifier for the fabrication of sensor to detect urea. The synthesized CoAl2O4 NPs are immobilized on a economical pencil electrode and this CoAl2O4 NPs modified pencil electrode is used to detect urea where it exhibits excellent sensing performance in terms of low detection limit, 6 µmol, with linear regression equation, y = 0.381x + 123.2. The sensitivity of the electrode is found to be 0.381 mA μmol−1. The proposed electrode also exhibits excellent stability over a period of 7 days without any significant loss in the performance.

Keywords

• CoAl2O4 nanoparticles
• Urea sensor
• Low detection limit
• Excellent sensitivity