title: Label-free, disposable fiber-optic biosensors for DNA hybridization detection.
abstract: A novel and highly sensitive fiber-optic DNA sensor based on a thin-core fiber modal interferometer (TCFMI) is demonstrated by using a layer-by-layer (LbL) self-assembly technology. Poly(ethylenimine) (PEI), poly(acrylic acid) (PAA) and single-stranded DNA (ssDNA) were used for the preparation of a polyelectrolyte multilayer film for DNA detection. The film thickness was measured through a surface profilometer. The surface morphologies of (PEI/PAA)4, (PEI/PAA)4.5 and (PEI/PAA)4(PEI/DNA)1 multilayer films were characterized by atomic force microscopy. The fabricated DNA sensors were tested with different types of target ssDNA solutions with a concentration of 1 μM. The results show that the sensitivity of the TCFMI-based ssDNA sensor is 0.27 nm/matched-base at the concentration of 1 μM and can even distinguish the number of matched bases of ssDNA chains.
authors: Photonics Research Centre, Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China. ming-jie.yin@connect.polyu.hk
authors: Ming-jie
authors: MJ
authors: Yin
authors: Chuang
authors: C
authors: Wu
authors: Li-yang
authors: LY
authors: Shao
authors: Wing Kin Edward
authors: WK
authors: Chan
authors: A Ping
authors: AP
authors: Zhang
authors: Chao
authors: C
authors: Lu
authors: Hwa-yaw
authors: HY
authors: Tam
mesh_terms: D000180:Acrylic Resins; D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded; D005336:Fiber Optic Technology; D007368:Interferometry; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D009693:Nucleic Acid Hybridization / Q000379:methods*; D011094:Polyethyleneimine
chemical_list: D000180:Acrylic Resins; D004277:DNA, Single-Stranded; D008567:Membranes, Artificial; C006903:carbopol 940; D011094:Polyethyleneimine