Low potential detection of NADH based on Fe3O4 nanoparticles/multiwalled carbon nanotubes composite: Fabrication of integrated dehydrogenase-based lactate biosensor

摘要: Abstract Fe 3 O 4 magnetic nanoparticles were in situ loaded on the surface of multiwalled carbon nanotubes (MWCNTs) by a simple coprecipitation procedure. The resulting /MWCNTs nanocomposite brings new capabilities for electrochemical sensing combining advantages and MWCNTs. It was found that has redox properties similar to those frequently used mediators electron transfer between NADH electrode. cyclic voltammetric results indicated ability modified GC electrode catalyze oxidation at very low potential (0.0 mV vs. Ag/AgCl) subsequently, substantial decrease overpotential about 650 mV compared with bare catalytic current allows stable selective amperometric detection an applied 0.0 mV (Ag/AgCl) limit 0.3 μM linear response up 300 μM. This can be as efficient transducer design biosensors based coupled dehydrogenase enzymes. Lactate (LDH) NAD + subsequently immobilized onto film covalent bond formation amine groups enzyme or carboxylic acid /MWCNT film. Differential pulse lactate /MWCNT/LDH/NAD gives responses over concentration range 50–500 μM 5 μM sensitivity 7.67 μA mM −1 . Furthermore, applicability sensor analysis human serum samples been successfully demonstrated.