title: Lipoxygenase-modified Ru-bpy/graphene oxide: Electrochemical biosensor for on-farm monitoring of non-esterified fatty acid.
abstract: Elevated concentrations of non-esterified fatty acids (NEFA) in biological fluids are recognized as critical biomarkers for early diagnosis of dairy cow metabolic diseases. Herein, a cost-effective, electrochemically active, and bio-friendly sensor element based on ruthenium bipyridyl complex-modified graphene oxide nanosheets ([Ru(bpy)3](2+)-GO) is proposed as a biosensor platform for NEFA detection. Electrochemical analysis demonstrates that the [Ru(bpy)3](2+)-GO electrodes exhibit superior and durable redox properties compared to the pristine carbon and GO electrodes. Target specificity is accomplished through immobilization of the enzyme, lipoxygenase, which catalyzes the production of redox active species from NEFA. Lipoxygenases retain their catalytic ability upon immobilization and exhibit changes to amperometric signals upon interaction with various concentrations of standard NEFA and serum samples. Our study demonstrates that the [Ru(bpy)3](2+)-GO electrode has the potential to serve as a biosensor platform for developing a field deployable, rapid, and user-friendly detection tool for on-farm monitoring of dairy cow metabolic diseases.
authors.affiliation: BioNano Laboratory, School of Engineering, University of Guelph, Guelph ON, Canada N1G 2W1.
authors.forename: Murugan
authors.initials: M
authors.lastname: Veerapandian
authors.affiliation: BioNano Laboratory, School of Engineering, University of Guelph, Guelph ON, Canada N1G 2W1.
authors.forename: Robert
authors.initials: R
authors.lastname: Hunter
authors.affiliation: BioNano Laboratory, School of Engineering, University of Guelph, Guelph ON, Canada N1G 2W1. Electronic address: sneethir@uoguelph.ca.
authors.forename: Suresh
authors.initials: S
authors.lastname: Neethirajan
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D002417:Cattle; D055664:Electrochemical Techniques; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000302:isolation & purification*; D006108:Graphite / Q000737:chemistry; D008084:Lipoxygenase / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry
chemical_list: D005231:Fatty Acids, Unsaturated; D010087:Oxides; D002244:Carbon; D006108:Graphite; D012428:Ruthenium; D008084:Lipoxygenase
keywords: NEFA; On-farm biosensor; Ruthenium (II)-graphene oxide; Soybean lipoxygenase