title: Flow-stress-induced discrimination of a K-ras point mutation by sandwiched polymer microsphere-enhanced surface plasmon resonance.
abstract: The highly sensitive detection of a K-ras point mutation with the aid of DNA-carrying microspheres as a flow-stress receptor is proposed at the surface of a surface plasmon resonance (SPR) biosensor. Single-stranded DNAs were immobilized onto epoxy-group-derivatized gold surfaces and the hybridization of DNA targets was monitored. The subsequent interaction with DNA-carrying micospheres enhanced the SPR response. The increase of flow rate during the event of dissociation changed the amount of detachment of the DNA-carrying microspheres for the mismatched pair. In addition, the viscosity was changed by addition of glycerol to the buffer. The increase of shear stress from the flow resulted in detachment of DNA-carrying microspheres hybridized with the mismatched sequence and increased the ability to discriminate a point mutation. This is a new method which not only increases the lower detection limit of evanescent wave-based biosensors, but also the ability to discriminate a point mutation which is a critical factor for ultrasensitive DNA detection in flow devices.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Sato
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sato
authors.forename: Aya
authors.initials: A
authors.lastname: Okumura
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Haruma
authors.initials: H
authors.lastname: Kawaguchi
mesh_terms: D004247:DNA / Q000737:chemistry; D004252:DNA Mutational Analysis / Q000379:methods*; D011905:Genes, ras; D006801:Humans; D008024:Ligands; D008863:Microspheres; D017354:Point Mutation; D020349:Surface Plasmon Resonance / Q000379:methods*; D013696:Temperature; D014783:Viscosity
chemical_list: D008024:Ligands; D004247:DNA