title: Sensitivity improved surface plasmon resonance biosensor for cancer biomarker detection based on plasmonic enhancement.
abstract: In this study, we report the development of a nanoparticle-enhanced biosensor by integrating both the nanoparticles and immunoassay sensing technologies into a phase interrogation surface plasmon resonance (SPR) system for detecting antigen at a concentration as low as the femtomolar range. Our work has demonstrated that the plasmonic field extension generated from the gold film to gold nanorod (GNR) has led to a drastic sensitivity enhancement. Antibody-functionalized sensing film, together with antibody-conjugated GNRs, was readily served as a plasmonic coupling partner that can be used as a powerful ultrasensitive sandwich immunoassay for cancer-related disease detection. Experimentally, it was found that the bioconjugated GNR labels enhance the tumor necrosis factor alpha (TNF-α) antigen signal with more than 40-fold increase compared to the traditional SPR biosensing technique. The underlying principle was analyzed by simulating the near-field coupling between the sensing film and the GNR. The results have shown that GNRs were readily served as promising amplification labels in SPR sensing technology.
authors.affiliation: Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo, Buffalo, New York 14260-3000, United States.
authors.forename: Wing-Cheung
authors.initials: WC
authors.lastname: Law
authors.forename: Ken-Tye
authors.initials: KT
authors.lastname: Yong
authors.forename: Alexander
authors.initials: A
authors.lastname: Baev
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad
mesh_terms: D000906:Antibodies / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D009369:Neoplasms / Q000175:diagnosis*; D055672:Static Electricity; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*; D013499:Surface Properties; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry / Q000378:metabolism
chemical_list: D000906:Antibodies; D014409:Tumor Necrosis Factor-alpha; D006046:Gold