title: Lipoprotein(a) determination in human serum using a nitrilotriacetic acid derivative immunosensing scaffold on disposable electrodes.
abstract: A novel strategy for the construction of a disposable integrated amperometric immunosensor for the sensitive and rapid determination of lipoprotein(a) (Lp(a)), an important predictor of cardiovascular disease risk, in human serum is reported. The approach uses a sandwich format involving the covalent immobilization of selective capture antibodies (antiLp(a)) on the surface of N-[Nα,Nα-bis(carboxymethyl)-lysine]-12-mercaptododecanamide (HS-NTA)-modified screen-printed carbon electrodes (SPCEs). After a blocking step with skimmed milk, the modified antiLp(a)-SPCEs were incubated with a mixture solution containing the target analyte and a fixed concentration of a specific biotinylated antibody (biotin-antiLp(a)) and a streptavidin-horseradish peroxidase (HRP) (Strep-HRP) conjugate. The amperometric responses of the resulting immunosensor at -0.10 V (vs an Ag pseudo-reference electrode), upon addition of 3,3',5,5'-tetramethylbenzidine (TMB) as electron transfer mediator and H2O2 as the enzyme substrate, were used to monitor the extent of the immunoreactions. The developed methodology exhibited a wide range of linearity between 0.02 and 10 μg mL(-1), a low detection limit (LOD) of 8 ng mL(-1), and a great selectivity against other serum components. The usefulness of the Lp(a) immunosensor was demonstrated by analyzing spiked serum samples as well as a reference serum containing a certified Lp(a) content.
authors: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
authors: Berta
authors: B
authors: Esteban-Fernández de Ávila
authors: Susana
authors: S
authors: Campuzano
authors: María
authors: M
authors: Pedrero
authors: J-Pablo
authors: JP
authors: Salvador
authors: M-Pilar
authors: MP
authors: Marco
authors: José M
authors: JM
authors: Pingarrón
mesh_terms: D001560:Benzidines / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D019921:Biotinylation; D002244:Carbon / Q000737:chemistry; D002318:Cardiovascular Diseases / Q000097:blood; D004563:Electrochemistry; D004566:Electrodes; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D017270:Lipoprotein(a) / Q000737:chemistry*; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D044967:Serum / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry
chemical_list: D001560:Benzidines; D017270:Lipoprotein(a); C021758:3,3',5,5'-tetramethylbenzidine; D002244:Carbon; D019809:Streptavidin; D006735:Horseradish Peroxidase; D009571:Nitrilotriacetic Acid