title: Nickel/cobalt oxide-decorated 3D graphene nanocomposite electrode for enhanced electrochemical detection of urea.
abstract: A NiCo2O4 bimetallic electro-catalyst was synthesized on three-dimensional graphene (3D graphene) for the non-enzymatic detection of urea. The structural and morphological properties of the NiCo2O4/3D graphene nanocomposite were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The NiCo2O4/3D graphene was deposited on an indium tin oxide (ITO) glass to fabricate a highly sensitive urea sensor. The electrochemical properties of the prepared electrode were studied by cyclic voltammetry. A high sensitivity of 166 μAmM(-)(1)cm(-)(2) was obtained for the NiCo2O4/3D graphene/ITO sensor. The sensor exhibited a linear range of 0.06-0.30 mM (R(2)=0.998) and a fast response time of approximately 1.0 s with a detection limit of 5.0 µM. Additionally, the sensor exhibited high stability with a sensitivity decrease of only 5.5% after four months of storage in ambient conditions. The urea sensor demonstrates feasibility for urea analysis in urine samples.
authors.affiliation: Department of Chemical and Bio Engineering, Gachon University, Gyeonggi-do 461-701, Republic of Korea.
authors.forename: Nhi Sa
authors.initials: NS
authors.lastname: Nguyen
authors.affiliation: Department of Chemical and Bio Engineering, Gachon University, Gyeonggi-do 461-701, Republic of Korea.
authors.forename: Gautam
authors.initials: G
authors.lastname: Das
authors.affiliation: Department of Chemical and Bio Engineering, Gachon University, Gyeonggi-do 461-701, Republic of Korea. Electronic address: hhyoon@gachon.ac.kr.
authors.forename: Hyon Hee
authors.initials: HH
authors.lastname: Yoon
mesh_terms: D003035:Cobalt / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008839:Microelectrodes; D053761:Nanocomposites / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014508:Urea / Q000652:urine*; D016482:Urinalysis / Q000295:instrumentation
chemical_list: D010087:Oxides; D003035:Cobalt; D006108:Graphite; D009532:Nickel; D014508:Urea; C060728:cobalt oxide
keywords: 3D graphene; Ni–Co oxide; Non-enzymatic; Urea sensor; Urine