Imaging of selenium in plants using tapered metal monocapillary optics

Tapered metal monocapillary optics provide a potential alternative to conventional methods of producing small X-ray beams. This paper presents the initial results of chemically specific imaging using such devices. Cellular resolution of organic selenium is obtained in a longitudinal section of mature Astragalus bisulcatus, a selenium hyperaccumulating plant. This work demonstrates the utility of metal monocapillary optics for imaging dilute levels of target elements in biological tissues.