Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), 85748 Garching, Germany.
Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute of Biological Information Processing (IBI-8), 52425 Jülich, Germany.
Rev Sci Instrum. 2023 Mar 1;94(3):034106. doi: 10.1063/5.0136367.
A new sample environment, called Bio-Oven, has been built for the Neutron Spin Echo (NSE) Spectrometer J-NSE Phoenix. It provides active temperature control and the possibility to perform Dynamic Light Scattering (DLS) measurements during the neutron measurement. DLS provides diffusion coefficients of the dissolved nanoparticles, and thus one can monitor the aggregation state of the sample on a time scale of minutes during the spin echo measurement times on the order of days. This approach helps to validate the NSE data or to replace the sample when its aggregation state influences the spin echo measurement results. The new Bio-Oven is an in situ DLS setup based on optical fibers decoupling the free space optics around the sample cuvette in a lightproof casing from the laser sources and the detectors. It collects light from three scattering angles simultaneously. Six different values of momentum transfer can be accessed by switching between two different laser colors. Test experiments were performed with silica nanoparticles with diameters ranging from 20 nm up to 300 nm. Their hydrodynamic radii were determined from DLS measurements and compared with the ones obtained by a commercial particle sizer. It was demonstrated that also the static light scattering signal can be processed and gives meaningful results. The protein sample apomyoglobin was used for a long-term test and in a first neutron measurement using the new Bio-Oven. The results prove that the aggregation state of the sample can be followed using in situ DLS along with the neutron measurement.
已为中子自旋回波（NSE）光谱仪 J-NSE Phoenix 构建了一个名为 Bio-Oven 的新样品环境。它提供了主动温度控制，并可在中子测量过程中进行动态光散射（DLS）测量。DLS 提供了溶解纳米粒子的扩散系数，因此可以在几天的自旋回波测量时间内，以分钟为时间尺度监测样品的聚集状态。这种方法有助于验证 NSE 数据，或者在样品的聚集状态影响自旋回波测量结果时替换样品。新的 Bio-Oven 是一种基于光纤的原位 DLS 装置，它将样品小瓶周围的自由空间光学与激光源和探测器隔离开来，形成一个不透光的外壳。它可以同时从三个散射角度收集光。通过在两种不同激光颜色之间切换，可以访问六个不同的动量转移值。使用直径从 20nm 到 300nm 的二氧化硅纳米粒子进行了测试实验。通过 DLS 测量确定了它们的水动力半径，并与商用颗粒度计获得的结果进行了比较。结果表明，静态光散射信号也可以进行处理并给出有意义的结果。无辅基肌红蛋白蛋白样品被用于长期测试和使用新的 Bio-Oven 的第一次中子测量。结果证明，通过原位 DLS 可以在进行中子测量的同时监测样品的聚集状态。
