title: 3D label-free prostate specific antigen (PSA) immunosensor based on graphene-gold composites.
abstract: Highly sensitive and label-free detection of the prostate specific antigen (PSA) remains a challenge in the diagnosis of prostate cancer. Here, a novel three-dimensional (3D) electrochemical immunosensor capable of sensitive and label-free detection of PSA is reported. This unique immunosensor is equipped with a highly conductive graphene (GR)-based gold (Au) composite modified electrode. The GR-based Au composite is prepared using aerosol spray pyrolysis and the morphology of the composite is the shape of a crumpled GR ball decorated with Au nanoparticles. Unlike the previous research, this novel 3D immunosensor functions very well over a broad linear range of 0-10 ng/mL with a low detection limit of 0.59 ng/mL; furthermore, it exhibits a significantly increased electron transfer and high sensitivity toward PSA. The highest rate of current change with respect to the PSA concentration is 5 μA/(ng/mL). Satisfactory selectivity, reproducibility, and stability of the 3D immunosensor are also exhibited.
authors.affiliation: Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Korea. Electronic address: hdjang@kigam.re.kr.
authors.forename: Hee Dong
authors.initials: HD
authors.lastname: Jang
authors.affiliation: Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Korea; Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea.
authors.forename: Sun Kyung
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Korea.
authors.forename: Hankwon
authors.initials: H
authors.lastname: Chang
authors.affiliation: Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea. Electronic address: jwchoi@sogang.ac.kr.
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Choi
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry; D017430:Prostate-Specific Antigen / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D013194:Staining and Labeling
chemical_list: D000906:Antibodies; D010087:Oxides; D006046:Gold; D006108:Graphite; D017430:Prostate-Specific Antigen
keywords: Aerosol spray pyrolysis; Crumpled graphene–gold composite; Label-free immunosensor; Prostate specific antigen (PSA)