title: A novel sugar-probe biosensor for the deadly plant proteinous toxin, ricin.
abstract: Because of the illegal use of highly toxic ricin from the castor-oil plant, Ricinus communis, in bioterrorism and suspected white powder cases, anti-terrorism measures for the toxin are urgently required. Here we demonstrate a facile and sensitive detection method using synthetic analogues of beta-lactosyl- and beta-d-galactosyl ceramides as the ligands based on the fact that ricin binds cell-surface oligosaccharides. Sugar-probes having lipoic acids as anchor functions were synthesized via either a chemical or chemoenzymatic way and were immobilized on the sensor chips by a self-assembled monolayer technique. Surface plasmon resonance (SPR) analysis using these carbohydrate probes allowed us to detect the toxin in a highly sensitive and facile manner (10 pg/mL, 5 min), being the best benchmark as a method for detecting the toxin. In addition, a visual monitoring method was developed, in which sugar-coated Au nanoparticles were utilized for discriminating ricin from other proteins in a facile manner, taking 10-30 min for judgment.
authors.affiliation: Research Center of Advanced Bionics, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Uzawa
authors.forename: Koji
authors.initials: K
authors.lastname: Ohga
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shinozaki
authors.forename: Isaac
authors.initials: I
authors.lastname: Ohsawa
authors.forename: Takehiro
authors.initials: T
authors.lastname: Nagatsuka
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Seto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nishida
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002241:Carbohydrates / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012276:Ricin / Q000032:analysis*; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D002241:Carbohydrates; D006046:Gold; D012276:Ricin