title: Sensing technique of silver nanoparticles as labels for immunoassay using liquid electrode plasma atomic emission spectrometry.
abstract: We report the use of liquid electrode plasma-atomic emission spectrometry (LEP-AES) in protein sensing studies employing Ag nanoparticle labeling. LEP-AES requires no plasma gas and no high-power source and is suitable for onsite portable analysis. Human chorionic gonadotropin (hCG) was used as a model target protein, and the immunoreaction in which hCG is sandwiched between two antibodies, one of which is immobilized on the microwell and the second is labeled with Ag nanoparticles, was performed. Sensing occurs at the narrow pass in the center of a quartz chip following oxidative dissolution of the Ag nanoparticles by nitric acid. hCG was analyzed in the range from 10 pg/mL to 1 ng/mL, and the detection limit for hCG was estimated at 1.3 pg/mL (22.8 fM). The proposed detection method has a wide variety of promising applications in metal-nanoparticle-labeled biomolecule detection.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Nguyen Hoang
authors.initials: NH
authors.lastname: Tung
authors.forename: Miyuki
authors.initials: M
authors.lastname: Chikae
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ukita
authors.forename: Pham Hung
authors.initials: PH
authors.lastname: Viet
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Takamura
mesh_terms: D055910:Antibodies, Immobilized / Q000276:immunology; D006063:Chorionic Gonadotropin / Q000032:analysis / Q000276:immunology; D004566:Electrodes; D006801:Humans; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry; D010084:Oxidation-Reduction; D012834:Silver / Q000737:chemistry*; D013054:Spectrophotometry, Atomic
chemical_list: D055910:Antibodies, Immobilized; D006063:Chorionic Gonadotropin; D012834:Silver; D017942:Nitric Acid