title: Magnetic immunoassay for cancer biomarker detection based on surface-enhanced resonance Raman scattering from coupled plasmonic nanostructures.
abstract: A surface-enhanced resonance Raman scattering (SERRS) sensor was developed for the ultrasensitive detection of cancer biomarkers. Capture antibody-coated silver shell magnetic nanoparticles (Fe3O4@Ag MNPs) were utilized as the CEA enrichment platform and the SERRS signal amplification substrate. Gold nanorods (AuNRs) were coated with a thin silver shell to be in resonance with the resonant Raman dye diethylthiatricarbocyanine iodide (DTTC) and the excitation wavelength at 785nm. The silver-coated AuNRs (Au@Ag NRs) were then modified with detection antibody as the SERRS tags. Sandwich immune complexes formed in the presence of the target biomarker carcinoembryonic antigen (CEA), and this formation induced the plasmonic coupling between the Au@Ag NRs and Fe3O4@Ag MNPs. The SERRS signal of DTTC molecules located in the coupled plasmonic nanostructures was significantly enhanced. As a result, the proposed SERRS sensor was able to detect CEA with a low limit of detection of 4.75fg/mL and a wide dynamic linear range from 10fg/mL to 100ng/mL. The sensor provides a novel SERRS strategy for trace analyte detection and has a potential for clinical applications.
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing 100850, PR China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Rong
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing 100850, PR China; College of Life Sciences & Bio-Engineering, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Chongwen
authors.initials: C
authors.lastname: Wang
authors.affiliation: College of Mechatronics and Automation, National University of Defense Technology, Changsha 410073, PR China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Transfusion Medicine, Beijing 100850, PR China. Electronic address: David_king@139.com.
authors.forename: Donggen
authors.initials: D
authors.lastname: Wang
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing 100850, PR China. Electronic address: ruixiao203@sina.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Xiao
authors.affiliation: Beijing Institute of Radiation Medicine, Beijing 100850, PR China. Electronic address: sqwang@bmi.ac.cn.
authors.forename: Shengqi
authors.initials: S
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002272:Carcinoembryonic Antigen / Q000097:blood*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D008175:Lung Neoplasms / Q000097:blood* / Q000175:diagnosis; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D002272:Carcinoembryonic Antigen; D058185:Magnetite Nanoparticles; D012834:Silver; D006046:Gold
keywords: Au@Ag nanorod; Carcinoembryonic antigen; Coupled plasmonic nanostructure; Fe(3)O(4)@Ag magnetic nanoparticle; Surface-enhanced resonance Raman scattering