title: Protective antigen detection using horizontally stacked hexagonal ZnO platelets.
abstract: Anthrax toxin detection before bacteremia, when toxin concentration is low, improves the chances of efficient treatment and cure. We present a novel technique for ultrasensitive detection of a protective antigen (PA(83)) of anthrax using an array of zinc oxide nanorods in conjunction with a FITC-labeled PA affinity peptide. The nanorods are composed of horizontally stacked hexagonal platelets which are uniformly spaced and grown unidirectionally upon a glass substrate via a new and simple technique. Images taken under UV emission demonstrate fluorescence sensitivity to PA as a function of antigen concentration, and a negative control using bovine serum albumin produced no fluorescence signal. The fluorescence signal of the PA-peptide complex is also significantly reduced in the absence of the nanorods, suggesting that the presence of ZnO nanorods inhibits the self-quenching properties of the fluorophore. A lower limit of detection for the assay system for PA is estimated at 150 aM, which demonstrates the possibility of using ZnO nanorods in biological sensor systems.
authors.affiliation: Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang-dong 17, Seoul, South Korea 133-791.
authors.forename: Hye-Yeon
authors.initials: HY
authors.lastname: Park
authors.forename: Hwang-Yong
authors.initials: HY
authors.lastname: Go
authors.forename: Satish
authors.initials: S
authors.lastname: Kalme
authors.forename: Rajaram S
authors.initials: RS
authors.lastname: Mane
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Han
authors.forename: Moon-Young
authors.initials: MY
authors.lastname: Yoon
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001408:Bacillus anthracis / Q000737:chemistry / Q000276:immunology*; D001427:Bacterial Toxins / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics; D016650:Fluorescein-5-isothiocyanate; D005453:Fluorescence; D036103:Nanotechnology / Q000379:methods; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D012680:Sensitivity and Specificity; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D010455:Peptides; C030325:anthrax toxin; D016650:Fluorescein-5-isothiocyanate; D015034:Zinc Oxide