title: Biconically tapered fiber optic probes for rapid label-free immunoassays.
abstract: We report use of U-shaped biconically tapered optical fibers (BTOF) as probes for label-free immunoassays. The tapered regions of the sensors were functionalized by immobilization of immunoglobulin-G (Ig-G) and tested for detection of anti-IgG at concentrations of 50 ng/mL to 50 µg/mL. Antibody-antigen reaction creates a biological nanolayer modifying the waveguide structure leading to a change in the sensor signal, which allows real-time monitoring. The kinetics of the antibody (mouse Ig-G)-antigen (rabbit anti-mouse IgG) reactions was studied. Hydrofluoric acid treatment makes the sensitive region thinner to enhance sensitivity, which we confirmed by experiments and simulations. The limit of detection for the sensor was estimated to be less than 50 ng/mL. Utilization of the rate of the sensor peak shift within the first few minutes of the antibody-antigen reaction is proposed as a rapid protein detection method.
authors.affiliation: Department of Physics and Astronomy, University of California, Los Angeles, 475 Portola Plaza, Los Angeles, CA 90095, USA. johnmiller@physics.ucla.edu.
authors.forename: John
authors.initials: J
authors.lastname: Miller
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, 565 Li Ka Shing Center, Berkeley, CA 94720, USA. afcastaneda@berkeley.edu.
authors.forename: Angelica
authors.initials: A
authors.lastname: Castaneda
authors.affiliation: Department of Biological Sciences, California State Polytechnic University, Pomona, 3801 W Temple Ave, Pomona, CA 91768, USA. kunhlee@cpp.edu.
authors.forename: Kun Ho
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Physics and Astronomy, California State Polytechnic University, Pomona, 3801 W Temple Ave, Pomona, CA 91768, USA. msanchez2@cpp.edu.
authors.forename: Martin
authors.initials: M
authors.lastname: Sanchez
authors.affiliation: Department of Biological Sciences, California State Polytechnic University, Pomona, 3801 W Temple Ave, Pomona, CA 91768, USA. aaortiz@cpp.edu.
authors.forename: Adrian
authors.initials: A
authors.lastname: Ortiz
authors.affiliation: Department of Physics, Mus Alparslan University, Istasyon Cad. 49100, Mus, Turkey. e.almaz@alparslan.edu.tr.
authors.forename: Ekrem
authors.initials: E
authors.lastname: Almaz
authors.affiliation: Department of Biology, Mus Alparslan University, Istasyon Cad. 49100, Mus, Turkey. z.turkoglu@alparslan.edu.tr.
authors.forename: Zuleyha Turkoglu
authors.initials: ZT
authors.lastname: Almaz
authors.affiliation: Department of Animal and Veterinary Sciences, California State Polytechnic University, Pomona, 3801 W Temple Ave, Pomona, CA 91768, USA. semurinda@cpp.edu.
authors.forename: Shelton
authors.initials: S
authors.lastname: Murinda
authors.affiliation: Department of Biological Sciences, California State Polytechnic University, Pomona, 3801 W Temple Ave, Pomona, CA 91768, USA. weijenlin@cpp.edu.
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Lin
authors.affiliation: Department of Physics and Astronomy, California State Polytechnic University, Pomona, 3801 W Temple Ave, Pomona, CA 91768, USA. esalik@cpp.edu.
authors.forename: Ertan
authors.initials: E
authors.lastname: Salik
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000378:metabolism; D000937:Antigen-Antibody Reactions / Q000187:drug effects; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D006820:Hyaluronic Acid / Q000494:pharmacology; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D007074:Immunoglobulin G / Q000737:chemistry* / Q000276:immunology; D007700:Kinetics; D051379:Mice; D055100:Optical Fibers; D011817:Rabbits
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G; C048844:anti-IgG; D006820:Hyaluronic Acid
references.citation: J Opt Soc Am. 1948 Sep;38(9):804-6
references.pmid: 18883925
references.citation: Biosens Bioelectron. 2011 Dec 15;30(1):328-32
references.pmid: 21993139
references.citation: Biosens Bioelectron. 2011 Mar 15;26(7):3367-70
references.pmid: 21236656
references.citation: J Immunol Methods. 1994 Oct 14;175(2):149-60
references.pmid: 7930644
references.citation: Biophys J. 2012 Apr 4;102(7):1685-91
references.pmid: 22500769
references.citation: Appl Phys Lett. 2011 Sep 5;99(10):103703-1037033
references.pmid: 21990943
references.citation: Sensors (Basel). 2011;11(4):3780-90
references.pmid: 22163821
references.citation: J Mol Recognit. 1999 Sep-Oct;12(5):293-9
references.pmid: 10556877
references.citation: Immunology. 1984 Mar;51(3):423-30
references.pmid: 6698574
references.citation: Biosensors (Basel). 2015 Apr 01;5(2):158-71
references.pmid: 25836359
references.citation: Biosens Bioelectron. 2005 Dec 15;21(6):871-80
references.pmid: 16257655
references.citation: Clin Chem. 1974 Aug;20(8):1071-5
references.pmid: 4546847