title: Nano-immunoassay with improved performance for detection of cancer biomarkers.
abstract: Nano-immunoassay utilizing surface-enhanced Raman scattering (SERS) effect is a promising analytical technique for early detection of cancer. In its current standing the assay is capable of discriminating samples of healthy individuals from samples of pancreatic cancer patients. Further improvements in sensitivity and reproducibility will extend practical applications of the SERS-based detection platforms to wider range of problems. In this report, we discuss several strategies designed to improve performance of the SERS-based detection system. We demonstrate that reproducibility of the platform is enhanced by using atomically smooth mica surface as a template for preparation of capture surface in SERS sandwich immunoassay. Furthermore, assay's stability and sensitivity can be further improved by using either polymer or graphene monolayer as a thin protective layer applied on top of the assay addresses. The protective layer renders signal to be more stable against photo-induced damage and carbonaceous contamination.
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department of Physics, University of Nebraska Omaha, Omaha, NE, USA. Electronic address: akrasnos@gmail.com.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Krasnoslobodtsev
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: María P
authors.initials: MP
authors.lastname: Torres
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Sukhwinder
authors.initials: S
authors.lastname: Kaur
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Vlassiouk
authors.affiliation: Iowa State University, Ames, IA, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lipert
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Maneesh
authors.initials: M
authors.lastname: Jain
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address: sbatra@unmc.edu.
authors.forename: Surinder K
authors.initials: SK
authors.lastname: Batra
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address: ylyubchenko@unmc.edu.
authors.forename: Yuri L
authors.initials: YL
authors.lastname: Lyubchenko
mesh_terms: D000368:Aged; D000538:Aluminum Silicates / Q000737:chemistry; D015415:Biomarkers / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000737:chemistry*; D003936:Diagnosis, Computer-Assisted; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006108:Graphite / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D050997:Nanomedicine / Q000379:methods*; D009369:Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000097:blood / Q000175:diagnosis; D011108:Polymers / Q000737:chemistry; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012542:Scattering, Radiation; D013059:Spectrum Analysis, Raman
chemical_list: D000538:Aluminum Silicates; D015415:Biomarkers; D014408:Biomarkers, Tumor; D011108:Polymers; D006108:Graphite; C011934:mica
keywords: AFM; Cancer biomarkers; Nano-immunoassay; Nanodiagnostics; Pancreatic cancer; Surface-enhanced Raman scattering (SERS)