title: Use of liposomal amplifiers in total internal reflection fluorescence fiber-optic biosensors for protein detection.
abstract: Evanescent-wave excited fluorescence technology has been demonstrated to enhance sensitivity and reduce matrix effects, making it suitable for biosensor development. In this study, we developed a liposome-based, total internal reflection fluorescence, fiber-optic biosensor (TIRF-FOB) for protein detection, which integrates a liposomal amplifier and sandwich immunoassay format with TIRF-FOB. In addition, the antibody-tagged and fluorophore-entrapped liposomes for heterogeneous detection of target molecules were designed and synthesized. This biosensor successfully detected the target protein (model analyzed here is IgG) with a limit of detection (LOD) of 2.0 attomoles for the target protein (equivalent to 2.0 pg/mL of protein presented in 150 μL of sample solution). The features of this ultra-sensitive liposomal TIRF-FOB are (i) fluorescence is excited via evanescent waves and amplified via liposomes; (ii) the use of two polyclonal antibodies in the sandwich assay format increases the specificity and lowers the cost of our assay. Based on the exceptional detection sensitivity and cost-effectiveness, we believe that the proposed biosensor has great potential as a practical, clinical diagnostic tool in the near future.
authors.affiliation: BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Ying-Feng
authors.initials: YF
authors.lastname: Chang
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Chen
authors.initials: C
authors.lastname: Fu
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Chen
authors.affiliation: BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Amily
authors.initials: A
authors.lastname: Fang-Ju Jou
authors.affiliation: Department of Optics and Photonics, National Central University, Taoyuan 32001, Taiwan.
authors.forename: Chii-Chang
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Graduate Institute of Electro-Optical Engineering, Chang Gung University, Taoyuan 33302, Taiwan; Healthy Aging Research Center, Chang Gung University, Taoyuan 33302, Taiwan.
authors.forename: Chien
authors.initials: C
authors.lastname: Chou
authors.affiliation: BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan; Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan. Electronic address: jaho@ntu.edu.tw.
authors.forename: Ja-An
authors.initials: JA
authors.lastname: Annie Ho
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007118:Immunoassay / Q000295:instrumentation; D007074:Immunoglobulin G / Q000032:analysis*; D008081:Liposomes / Q000737:chemistry*; D040081:Protein Array Analysis / Q000295:instrumentation*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
chemical_list: D007074:Immunoglobulin G; D008081:Liposomes
keywords: Evanescent wave-excited fluorescence; Fiber-optic biosensors; Liposomes; Protein detection