title: Small biomolecule immunosensing with plasmonic optical fiber grating sensor.
abstract: This study reports on the development of a surface plasmon resonance (SPR) optical fiber biosensor based on tilted fiber Bragg grating technology for direct detection of small biomarkers of interest for lung cancer diagnosis. Since SPR principle relies on the refractive index modifications to sensitively detect mass changes at the gold coated surface, we have proposed here a comparative study in relation to the target size. Two cytokeratin 7 (CK7) samples with a molecular weight ranging from 78 kDa to 2.6 kDa, respectively CK7 full protein and CK7 peptide, have been used for label-free monitoring. This work has first consisted in the elaboration and the characterization of a robust and reproducible bioreceptor, based on antibody/antigen cross-linking. Immobilized antibodies were then utilized as binding agents to investigate the sensitivity of the biosensor towards the two CK7 antigens. Results have highlighted a very good sensitivity of the biosensor response for both samples diluted in phosphate buffer with a higher limit of detection for the larger CK7 full protein. The most groundbreaking nature of this study relies on the detection of small biomolecule CK7 peptides in buffer and in the presence of complex media such as serum, achieving a limit of detection of 0.4 nM.
authors.affiliation: Proteomics and Microbiology Laboratory, University of Mons, Mons, Belgium; Electromagnetism and Telecommunication Department, University of Mons, Mons, Belgium. Electronic address: clotilde.ribaut@umons.ac.be.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Ribaut
authors.affiliation: Electromagnetism and Telecommunication Department, University of Mons, Mons, Belgium.
authors.forename: Valérie
authors.initials: V
authors.lastname: Voisin
authors.affiliation: Proteomics and Microbiology Laboratory, University of Mons, Mons, Belgium; Electromagnetism and Telecommunication Department, University of Mons, Mons, Belgium.
authors.forename: Viera
authors.initials: V
authors.lastname: Malachovská
authors.affiliation: Proteomics and Microbiology Laboratory, University of Mons, Mons, Belgium.
authors.forename: Valentin
authors.initials: V
authors.lastname: Dubois
authors.affiliation: Electromagnetism and Telecommunication Department, University of Mons, Mons, Belgium.
authors.forename: Patrice
authors.initials: P
authors.lastname: Mégret
authors.affiliation: Proteomics and Microbiology Laboratory, University of Mons, Mons, Belgium.
authors.forename: Ruddy
authors.initials: R
authors.lastname: Wattiez
authors.affiliation: Electromagnetism and Telecommunication Department, University of Mons, Mons, Belgium. Electronic address: christophe.caucheteur@umons.ac.be.
authors.forename: Christophe
authors.initials: C
authors.lastname: Caucheteur
mesh_terms: D000941:Antigens / Q000276:immunology*; D015374:Biosensing Techniques / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007118:Immunoassay / Q000295:instrumentation*; D053552:Keratin-7 / Q000276:immunology*; D012031:Refractometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D000941:Antigens; D053552:Keratin-7
keywords: Cytokeratin 7 biomarker; Fiber optic biosensor; Small biomolecule detection; Surface plasmon resonance; Tilted fiber Bragg grating