title: Novel electrochemical catalysis as signal amplified strategy for label-free detection of neuron-specific enolase.
abstract: A label-free electrochemical immunoassay for neuron-specific enolase (NSE), a kind of lung cancer marker, was developed in this work via novel electrochemical catalysis for signal amplification. The new amplified strategy was based on the electrochemical catalysis of nickel hexacyanoferrates nanoparticles (NiHCFNPs) in the presence of dopamine (DA). NiHCFNPs, which were assembled on the porous gold nanocrystals (AuNCs) modified glassy carbon electrode (GCE), could exhibit a distinct pair of redox peaks corresponding to anodic and cathodic reactions of hexacyanoferrate (II/III). Subsequently, gold nanoparticles functionalized graphene nanosheets (Au-Gra) were coated on the surface of NiHCFNPs/AuNCs film. Then an enhanced amount of neuron-specific enolase antibody (anti-NSE) could be loaded to obtain a sensitive immunosensor of anti-NSE/Au-Gra/NiHCFNPs/AuNCs/GCE due to the strong adsorption capacity and large specific surface area of Au-Gra. More importantly, the oxidation peak current can be enormously enhanced towards the electrocatalytic oxidation of DA based on NiHCFNPs, resulting in the further improvement of the immunosensor sensitivity. Under optimal conditions, the electrochemical immunosensor exhibited a linear range of 0.001-100 ng/mL with a detection limit of 0.3 pg/mL (S/N=3). Thus, the proposed immunosensor provides a rapid, simple, and sensitive immunoassay protocol for NSE detection, which may hold a promise for clinical diagnosis.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhuo
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Chai
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Yuan
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D000669:Amplifiers, Electronic; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002384:Catalysis; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D010751:Phosphopyruvate Hydratase