title: Quantitative multiplex detection of pathogen biomarkers on multichannel waveguides.
abstract: No single biomarker can accurately predict disease. An ideal biodetection technology should be capable of the quantitative, reproducible, and sensitive detection of a limited suite of such molecules. To this end, we have developed a multiplex biomarker assay for protective antigen and lethal factor of the Bacillus anthracis lethal toxin using semiconductor quantum dots as the fluorescence reporters on our waveguide-based biosensor platform. The platform is extendable to a wide array of biomarkers, facilitating rapid, quantitative, sensitive, and multiplex detection, better than achievable by conventional immunoassay. Our assay allows for the sensitive (limit of detection 1 pM each), specific (minimal nonspecific binding), and rapid (15 min) detection of these biomarkers in complex biological samples (e.g., serum). To address the issue of reproducibility in measurement and to increase our sample throughput, we have incorporated multichannel waveguides capable of simultaneous multiplex detection of biomarkers in three samples in quadruplicate. In this paper, we present the design, fabrication, and development of multichannel waveguides for the simultaneous detection of lethal factor and protective antigen in serum. Evaluation of the multichannel waveguide shows an excellent concordance with single-channel data and effective, simultaneous, and reproducible measurement of lethal toxins in three samples.
authors.affiliation: Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Harshini
authors.initials: H
authors.lastname: Mukundan
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Xie
authors.forename: Dominique
authors.initials: D
authors.lastname: Price
authors.forename: Jessica Z
authors.initials: JZ
authors.lastname: Kubicek-Sutherland
authors.forename: W Kevin
authors.initials: WK
authors.lastname: Grace
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Anderson
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Martinez
authors.forename: Nile
authors.initials: N
authors.lastname: Hartman
authors.forename: Basil I
authors.initials: BI
authors.lastname: Swanson
mesh_terms: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D015415:Biomarkers; D055767:Immobilized Proteins; D007150:Immunohistochemistry / Q000295:instrumentation* / Q000379:methods*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D015415:Biomarkers; D055767:Immobilized Proteins; C030325:anthrax toxin