Department de Física Aplicada i Optica, IN2UB, Universitat de Barcelona, Barcelona, Catalonia, Spain.
Orig Life Evol Biosph. 2010 Feb;40(1):27-40. doi: 10.1007/s11084-009-9184-3. Epub 2009 Nov 13.
We present an experimental approach to the study of the chirality of three CM2 meteorite solid samples by direct measurement of the optical activity (circular birefringence; CB). The measurements are based on transmission two modulator generalized ellipsometry in conjuction with microscope optics to map the CB of the samples. In spite of the complexity of such optical analysis, these first results indicate the presence of optically active areas in the meteorite solid matrix. In the case of the Murchison sample the statistics of the CB mapping shows a bimodal distribution with a bias to negative CB values. The composition of the active areas probably corresponds to serpentines and other poorly identified phyllosilicate phases. The results are compatible with the hypothesis that in a mineral-based scenario for the origin of life a CB sign bias in the chiral fractures originated by mechanical and flow shear gradients on clays could be later transferred to the reactions of the absorbed organic compounds.
我们提出了一种实验方法，通过直接测量旋光性（圆二色性；CB）来研究三个 CM2 陨石固体样品的手性。测量基于传输两个调制广义椭圆偏振计与显微镜光学相结合，以绘制样品的 CB。尽管这种光学分析很复杂，但这些初步结果表明陨石固体基质中存在具有旋光活性的区域。在默奇森样品的情况下，CB 映射的统计数据显示出双峰分布，偏向于负 CB 值。活性区域的组成可能对应于蛇纹石和其他未被充分识别的层状硅酸盐相。这些结果与以下假设一致：在手性断裂起源的矿物为基础的生命起源情景中，机械和流剪切梯度在粘土上产生的手性断裂的 CB 符号偏差，可能会随后转移到被吸收的有机化合物的反应中。
