title: Evaluation of a novel ultra-sensitive nanoparticle probe-based assay for ricin detection.
abstract: A gold nanoparticle (GNP) probe-based assay (GNPA) modified from the bio-barcode assay (BCA) was developed for ultrasensitive detection of ricin, a potential biothreat agent. In the GNPA, a chain of ricin was captured by a GNP probe coated with polyclonal antibodies and single-stranded signal DNA. A magnetic microparticle (MMP) probe coated with ricin A chain monoclonal antibody was then added to form an immuno-complex. After being magnetically separated, the immuno-complex containing the single-stranded signal DNA was characterized by PCR and real-time PCR. A detection limit of 10(-2) fg/ml was determined for the ricin A chain; this is eight orders of magnitude more sensitive than that achieved with an ELISA and two orders more sensitive than that obtained with the BCA. The coefficients of variation (CV) of the intra- and inter-assay values ranged from 3.82-6.46%. The results here show that this novel assay is an ultrasensitive method for detection of ricin proteins and may be suitable for the ultrasensitive detection of other proteins.
authors.affiliation: Institute of Transfusion Medicine, Academy of Military Medical Sciences . Beijing , PR China and.
authors.forename: Hui-qiong
authors.initials: HQ
authors.lastname: Yin
authors.forename: Min-xian
authors.initials: MX
authors.lastname: Jia
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Shi
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Mao-min
authors.initials: MM
authors.lastname: Lv
authors.forename: Yu-yuan
authors.initials: YY
authors.lastname: Ma
authors.forename: Xiong
authors.initials: X
authors.lastname: Zhao
authors.forename: Jin-gang
authors.initials: JG
authors.lastname: Zhang
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism*; D002619:Chemical Warfare Agents / Q000032:analysis*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007163:Immunosorbent Techniques; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000706:statistics & numerical data*; D015588:Observer Variation; D012276:Ricin / Q000032:analysis* / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D002619:Chemical Warfare Agents; D004277:DNA, Single-Stranded; D058185:Magnetite Nanoparticles; D006046:Gold; D012276:Ricin
keywords: Gold nanoparticle probe-based assay; high-sensitivity detection; real-time PCR; ricin