Weingart Maximilian, Chen Siyu, Donat Clara, Helmbrecht Vanessa, Orsi William D, Braun Dieter, Alim Karen
Systems Biophysics and Center for NanoScience (CeNS), Ludwig-Maximilians University Munich, Amalienstraße 54, 80799 München, Germany.
Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany.
Sci Adv. 2023 Sep 29;9(39):eadi1884. doi: 10.1126/sciadv.adi1884.
Alkaline vents (AVs) are hypothesized to have been a setting for the emergence of life, by creating strong gradients across inorganic membranes within chimney structures. In the past, three-dimensional chimney structures were formed under laboratory conditions; however, no in situ visualization or testing of the gradients was possible. We develop a quasi-two-dimensional microfluidic model of AVs that allows spatiotemporal visualization of mineral precipitation in low-volume experiments. Upon injection of an alkaline fluid into an acidic, iron-rich solution, we observe a diverse set of precipitation morphologies, mainly controlled by flow rate and ion concentration. Using microscope imaging and pH-dependent dyes, we show that finger-like precipitates can facilitate formation and maintenance of microscale pH gradients and accumulation of dispersed particles in confined geometries. Our findings establish a model to investigate the potential of gradients across a semipermeable boundary for early compartmentalization, accumulation, and chemical reactions at the origins of life.
碱性热液喷口被认为是生命起源的一个环境，因为它能在烟囱结构内的无机膜上形成强烈的梯度。过去，三维烟囱结构是在实验室条件下形成的；然而，无法对梯度进行原位可视化或测试。我们开发了一种碱性热液喷口的准二维微流体模型，该模型能够在小体积实验中对矿物沉淀进行时空可视化。将碱性流体注入酸性富铁溶液后，我们观察到了一系列不同的沉淀形态，主要受流速和离子浓度控制。通过显微镜成像和pH依赖性染料，我们发现手指状沉淀能够促进微尺度pH梯度的形成和维持，以及在受限几何形状中分散颗粒的积累。我们的研究结果建立了一个模型，用于研究半透性边界上的梯度在生命起源时对早期区室化、积累和化学反应的潜力。
