title: Integrated microfluidic systems with an immunosensor modified with carbon nanotubes for detection of prostate specific antigen (PSA) in human serum samples.
abstract: This paper describes the development of an immunosensor coupled to glassy carbon electrode (GCE) modified with multiwall carbon nanotubes (MWCNT) (CNT-GCE) integrated with microfluidic systems for rapid and sensitive quantification of prostate specific antigen (PSA) in human serum samples. Mouse monoclonal (5G6) to PSA antibodies were immobilized on a rotating disk. PSA in the serum sample are allowed to react immunologically with the immobilized anti-tPSA and horseradish peroxidase (HRP) enzyme-labeled second antibodies specific to PSA. HRP, in the presence of hydrogen peroxide (H(2)O(2)) catalyzes the oxidation of 4-tert-butylcatechol (4-TBC), whose back electrochemical reduction was detected on CNT-GCE at -0.15 V. The electrochemical detection can be done within 1 min and total assay time was 30 min. The calculated detection limits for electrochemical detection and the ELISA procedure are 0.08 and 0.5 microg L(-1), respectively and the intra- and inter-assay coefficients of variation were below 4.5%. The electrochemical immunosensor showed higher sensitivity and lower time consumed than the standard spectrophotometric detection ELISA method, which shows potential for detecting PSA in clinical diagnosis.
authors.affiliation: Departamento de Química, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, CONICET, Chacabuco y Pedernera, San Luis, Argentina.
authors.forename: Nancy V
authors.initials: NV
authors.lastname: Panini
authors.forename: Germán A
authors.initials: GA
authors.lastname: Messina
authors.forename: Eloy
authors.initials: E
authors.lastname: Salinas
authors.forename: Héctor
authors.initials: H
authors.lastname: Fernández
authors.forename: Julio
authors.initials: J
authors.lastname: Raba
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001774:Blood Chemical Analysis / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D008839:Microelectrodes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D017430:Prostate-Specific Antigen / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018511:Systems Integration
chemical_list: D037742:Nanotubes, Carbon; D017430:Prostate-Specific Antigen