A nanoplasmonic biosensor for label-free multiplex detection of cancer biomarkers

The development of highly sensitive, selective and multiplex sensors has become an important challenge for disease diagnosis. In this study, we describe a multiplex biosensor for the detection of cancer biomarkers based on unique plasmon response of single gold nanoparticles (AuNPs) and antibody-antigen binding activity. To demonstrate the ability of the plasmon biosensor to detect and quantify cancer biomarkers: a panel of biomarkers, including alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and prostate specific antigen (PSA) was used as a model analyte for multiple detection. A novel and sensitive multiplex biosensor was developed by immobilizing plasmonic nanoparticles in a site-specific manner and functionalized with monoclonal antibodies that recognize the target protein on hydrophilic-hydrophobic patterned glass slide. The proposed multi-analyte biosensor exhibited outstanding selectivity and sensitivity. The limit of detection was determined to be 91 fM, 94 nil and 10 fM for AFP, CEA and PSA from patient-mimicked serum, respectively. Finally, using this sensing strategy, this platform presents an excellent approach for versatile molecular diagnostics in both research and clinical medical fields. (C) 2015 Elsevier B.V. All rights reserved.