title: A polydopamine-modified optical fiber SPR biosensor using electroless-plated gold films for immunoassays.
abstract: A sensitive and stable electroless-plated gold film for the preparation of an optical fiber surface plasmon resonance (SPR) sensor is presented in this work, together with a facile antibody immobilization method. Gold nanoparticles were uniformly adsorbed onto the surface of an optical fiber forming a film with a thickness of approximately 56.3 nm. The sensor had a high sensitivity with 2054 nm/RIU and 3980 nm/RIU in the refractive index ranges of 1.333-1.359 and 1.359-1.386, respectively. An SPR biosensor was developed based on polydopamine-modified gold film (PDA-Au), which was fabricated by a simple and quick spontaneous polymerization of dopamine (DA) on the gold film. When goat anti-human IgG antibodies were immobilized, the PDA-Au surface had a larger resonant wavelength shift of 66.21 nm compared with the traditional 11-mercaptoundecanoic acid-modified gold film (MUA-Au) surface. In addition, the PDA-Au surface enabled the sensitive and selective determination of human IgG down to a concentration of 2 μg mL(-1) with a high sensitivity of 0.41 nm per μg mL(-1). The PDA-Au surface exhibited an approximately four fold higher sensitivity and an about seven fold lower LOD than the MUA-Au surface to human IgG.
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Se
authors.initials: S
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Research Center of Hunan Entry-Exit Inspection and Quarantine Bureau, Changsha 410001, China.
authors.forename: Libing
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China. Electronic address: surx@tju.edu.cn.
authors.forename: Rongxin
authors.initials: R
authors.lastname: Su
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Boshi
authors.initials: B
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Renliang
authors.initials: R
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: He
mesh_terms: D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D007211:Indoles / Q000737:chemistry*; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D020099:Coated Materials, Biocompatible; D007211:Indoles; D008567:Membranes, Artificial; D011108:Polymers; C568283:polydopamine; D006046:Gold
keywords: Antibody immobilization; Electroless plating; Immunoassays; Optical fiber SPR biosensor; Polydopamine; Surface functionalization