کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4681157 1634949 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
An integrated approach for determining the origin of magnetite nanoparticles
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
An integrated approach for determining the origin of magnetite nanoparticles
چکیده انگلیسی

The criteria to assess the origin of magnetite are of prime importance because of their significance as biomarkers for extraterrestrial life and paleoenvironmental indicators. It is still unclear if morphology and magnetic properties of crystals do quantitatively allow differentiating abiotic from biotic magnetite crystals of nanometer size. In this study, inorganic magnetite nanocrystals synthesized under controlled experimental aqueous conditions are compared with biogenic magnetite of similar size and morphology formed by magnetotactic (intracellular magnetite) and other (extracellular magnetite) bacteria. Structural properties such as oxygen isotope fractionations and crystal size distributions were explored. Not surprisingly, none of the single properties are able to differentiate inorganic crystals from those having a bacterial origin, either specifically extracellular or specifically intracellular. However, oxygen isotope fractionation allows the differentiation between abiotic and biotic magnetite when the temperature of formation is known and when it does not fall into a crossing region (35 ≤ T (°C) ≤ 55) while crystal size distributions discriminate inorganic from intracellular magnetite. Therefore, a combination of these two properties may be a successful tool for an accurate determination of a reliable biogenicity criterion.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 243, Issues 1–2, 15 March 2006, Pages 53–60
نویسندگان
, ,