title: Interference terahertz label-free imaging for protein detection on a membrane.
abstract: We demonstrate a highly sensitive imaging method combined a terahertz time-domain spectroscopy and an interference effect for label-free protein detection on a polyvinylidene difluoride membrane. The method is based on terahertz time-domain spectroscopy and uses an interference effect. Biotin is linked to the membrane using poly ethylene glycol or poly ethylene glycol methyl ether to prevent it from being washed off. Binding of the biotin with streptavidin is then observed by measuring the terahertz signal change due to the variation of the membrane refractive index. We demonstrate the detection of the binding streptavidin protein in gradually decreasing concentrations, down to 27 ng mm-2, using the image recorded at 1.5 THz.
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiya-machi, Aoba-ku, Sendai 981-8555, Japan. yogawa@bios.tohoku.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Shin'ichiro
authors.initials: S
authors.lastname: Hayashi
authors.forename: Masato
authors.initials: M
authors.lastname: Oikawa
authors.forename: Chiko
authors.initials: C
authors.lastname: Otani
authors.forename: Kodo
authors.initials: K
authors.lastname: Kawase
mesh_terms: D000818:Animals; D001710:Biotin / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism*; D004867:Equipment Design; D007368:Interferometry / Q000295:instrumentation / Q000379:methods*; D008565:Membrane Proteins / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry*; D011485:Protein Binding; D011506:Proteins / Q000032:analysis*; D019809:Streptavidin / Q000737:chemistry; D055068:Terahertz Spectroscopy / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D005465:Fluorocarbon Polymers
chemical_list: D001710:Biotin; D008565:Membrane Proteins; D011092:Polyethylene Glycols; D011145:Polyvinyls; D011506:Proteins; D019809:Streptavidin; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers; C028210:monomethoxypolyethylene glycol