Label electrochemical immunosensor for prostate-specific antigen based on graphene and silver hybridized mesoporous silica

Prostate-specific antigen (PSA), as the specificity of prostate cancer markers, has been widely used in prostate cancer diagnosis and screening. In this study, we fabricated an electrochemical immunosensor for PSA detection using the amino-functionalized graphene sheet-ferrocenecarboxaldehyde composite materials (NH2-GS@FCA) and silver hybridized mesoporous silica nanoparticles (Ag@NH2-MCM48). Under optimal conditions, the fabricated immunosensor showed a wide linear range with PSA concentration (0.01-10.0 ng.ml(-1)). Low detection limit (2 pg.ml(-1)) proved the high sensitivity. In addition, the immunosensor possessed good stability and reproducibility. Moreover, the application to PSA analysis in serum samples yielded satisfactory results. (C) 2014 Elsevier Inc. All rights reserved.