title: Sensitive immunoassay detection of multiple environmental chemicals on protein microarrays using DNA/dye conjugate as a fluorescent label.
abstract: Indirect competitive immunoassays were developed on protein microarrays for the sensitive and simultaneous detection of multiple environmental chemicals in one sample. In this assay, a DNA/SYTOX Orange conjugate was employed as an antibody label to increase the fluorescence signal and sensitivity of the immunoassays. Epoxy-modified glass slides were selected as the substrate for the production of 4 × 4 coating antigen microarrays. With this signal-enhancing system, competition curves for 17β-estradiol (E2), benzo[a]pyrene (BaP) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) were obtained individually on the protein microarray. The IC(50) and calculated limit of detection (LOD) are 0.32 μg L(-1) and 0.022 μg L(-1) for E2, 37.2 μg L(-1) and 24.5 μg L(-1) for BaP, and 31.6 μg L(-1) and 2.8 μg L(-1) for BDE-47, respectively. LOD of E2 is 14-fold lower than the value reported in a previous study using Cy3 labeled antibody (Du et al., Clin. Chem, 2005, 51, 368-375). The results of the microarray immunoassay were within 15% of chromatographic analysis for all three pollutants in spiked river water samples, thus verifying the immunoassay. Simultaneous detection of E2, BaP and BDE-47 in one sample was demonstrated. There was no cross-reaction in the immunoassay between these three environmental chemicals. These results suggest that microarray-based immunoassays with DNA/dye conjugate labels are useful tools for the rapid, sensitive, and high throughput screening of multiple environmental contaminants.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environment Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Ziyan
authors.initials: Z
authors.lastname: Fan
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Keum
authors.forename: Qing X
authors.initials: QX
authors.lastname: Li
authors.forename: Weilin L
authors.initials: WL
authors.lastname: Shelver
authors.forename: Liang-Hong
authors.initials: LH
authors.lastname: Guo
mesh_terms: D001564:Benzo(a)pyrene / Q000032:analysis; D004247:DNA / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D004958:Estradiol / Q000032:analysis; D005456:Fluorescent Dyes / Q000737:chemistry*; D005618:Fresh Water; D055768:Halogenated Diphenyl Ethers / Q000032:analysis; D007118:Immunoassay; D011075:Polybrominated Biphenyls; D040081:Protein Array Analysis; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D055768:Halogenated Diphenyl Ethers; D011075:Polybrominated Biphenyls; D014874:Water Pollutants, Chemical; C511295:2,2',4,4'-tetrabromodiphenyl ether; D001564:Benzo(a)pyrene; D004958:Estradiol; D004247:DNA