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Stigmatic Isotope Imaging Method for Biology and Cosmochemistry
Isotope Imaging Laboratory, Hokkaido University, Sapporo 060-0810, JAPAN ([email protected])
Naoya Sakamoto and Hisayoshi Yurimoto
16O 17O 18O
Presolar Grain
10µm
Meteorite
Meteorites contain isotopically anormalous grains thought to be of extrasolar origin. Stigmatic isotope imaging allows us to survey in broad area quickly. (Nagashima et al., 2004, Nature)
Presolar Silicate Molecular Cloud Water
17O/16O 18O/16O
5 µm
Molecular cloud origin model for the systematic mass independent fractionation of oxygen in the Solar System predicted “heavy” water enriched in 17,18O (Yurimoto and Kuramoto, 2004, Sciecne). Such material happened to be detected during presoalr grain survey. The material shows nano-scale symplectite structure composed of FeS and Fe3O4 that formed by aqueous alteration of 17,18O enriched water (Sakamoto et al., 2007, Science).
Cosmic Symplectite
Moon WaterAdsorbed hydrogen
Apatite
1H
Crack
Crack
Apollo 11 sample
Apollo mission brought many lunar rocks back to the earth. Recently, we detected significant amounts of water is enriched in duterium. The Isotopograph cleary shows that apatite has a high hydrogen concen-tration compared to surrounding anhy-drous minerals. (Greenwood et al., 2011, Nature Geoscience)
-400
-200
0
200
400
600
800
1000
1200
-0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4
12039,4312039,4210044,1210044,64475055,5514053,25614053,25712040,21114305,30314305,9512013,14810047,22879215,7412064,872395,6
D‰
SM
OW
OH (wt.%)
The demand of visualization methods without additional tracer disturbing the natural environments is incrasing in the medical field.The Isotopograph shows incorporation of 18O-doped RNA into cells. (Hamasaki et al., in prep).
Gene12C14N 18O 18O-RNA10µm
Imaging Depth30Si
18O
Depth
Bulk diffusion
Grain boundary diffusion
18O (shallow) 18O (deep)
50µm 50µm
Stigmatic imaging method realizes practical imaging depth profiling because probe cur-rent can increase without degradation of spatial resolution. Figures show snapshots from 18O imaging depth profiling for 18O-diffused ZnO polycrystal (Sakaguchi et al., in prep).
12 C14N 15N/14N
Fungus penetrates the cells of the roots of a vascular plant and interacts materially. Isotopographs show dynamical ex-change of 15N-doped fertilizer between a plant and arbuscu-lar mycorrhiza. (Kuga et al., in prep)
Mutualism in Plants
cell wall
nucleus
fungus
First Solid in the Solar SystemMgCaAl
Ca-Al rich inclusions in meteorites are ag-gregates of the first solids in the solar system. Conbination of chemical and isotopic zoning of melilite single crystal in the Ca-Al rich inclusions can reveal its formation condi-tions in the solar nebula. (Park et al., 2011)
44Ca/40Ca
Bone growthBone growth of animals is visualized by feeding 44Ca-doped food during a set time period. Steped concentration is ob-served in inner and outer parts.(Kimura-Suda et al., in prep)
44Ca/40Ca
< 30nm
2 m
Pixel electrode
ion Secondary
electron
Si Device
SCAPS (Stacked CMOS Active Pixel Sensor)
10mm
Direct ditection of ion Integral type No deadtime Wide dynamic range Robust
Scan coil
Reconstruction
0-D ion detector
Focused beam
Scanning
Broad beam
Lens, Magnet
2-D ion detector
Stigmatic
Stigmatic Isotope Imaging
2-D Ion Detector “SCAPS”Performance (in case of ims1270)
・High spatial resolution with a fine probe size・Long measurement time for wide area - High precision analysis is difficult for wide area
・Spatial resolution is limited by ion optics・Wide area with high Intensity signals - High precision analysis
Measurement time : 5 secField of view : 50 x 70 µmSpatial resolution : 300nmPrimary beam : Cs+, 1nA
12C14N
