Specht Agnes, Krämer Dominik, Helfricht Nicolas, Papastavrou Georg
Department of Physical Chemistry II, University of Bayreuth, Universitaetsstrasse 30, Bayreuth 95447, Germany.
Bavarian Polymer Institute, University of Bayreuth, Universitaetsstrasse 30, Bayreuth 95447, Germany.
Langmuir. 2025 Mar 18;41(10):6515-6527. doi: 10.1021/acs.langmuir.4c03519. Epub 2025 Jan 29.
Direct force measurements by atomic force microscopy (AFM) have become an indispensable analytical tool in the last decades. Force measurements have been widely used for adhesion measurements, often in combination with the colloidal probe technique. For the latter technique, a colloidal particle is attached to the end of an AFM cantilever, proving great flexibility in terms of colloid/surface interaction to be studied. Interestingly, the question of how much data is necessary to obtain statistically reliable results has been addressed in this context only sparsely. By contrast, the value and necessity of determining and reporting distributions of adhesion forces has been widely accepted. Here, simple statistical methods of the experimental design have been applied to address this question. It has been demonstrated that it is possible to determine an optimal number of force curves even during data acquisition. This approach would be essential to prevent oversampling of data. Moreover, it allows to address questions like heterogeneity of the sample in a more reliable or less time-consuming way. In AFM measurements with colloidal probes, most statistical variation results from the surface roughness of the probe particle. In this case, the use of different colloidal particles is important, which can be achieved by techniques such as fluidic force microscopy (FluidFM). The latter enables to combine a real-time determination of the required data size and high-throughput techniques of unattended measurements, which will open new fields of analysis.
在过去几十年中，通过原子力显微镜（AFM）进行的直接力测量已成为一种不可或缺的分析工具。力测量已广泛用于粘附力测量，通常与胶体探针技术结合使用。对于后一种技术，将一个胶体颗粒附着在AFM悬臂的末端，这在研究胶体/表面相互作用方面具有很大的灵活性。有趣的是，在这种情况下，关于需要多少数据才能获得统计上可靠的结果这一问题只是很少被提及。相比之下，确定和报告粘附力分布的价值和必要性已被广泛接受。在此，应用了实验设计的简单统计方法来解决这个问题。已经证明，即使在数据采集过程中也能够确定力曲线的最佳数量。这种方法对于防止数据过采样至关重要。此外，它能够以更可靠或更省时的方式解决诸如样品异质性等问题。在使用胶体探针的AFM测量中，大多数统计变化来自探针颗粒的表面粗糙度。在这种情况下，使用不同的胶体颗粒很重要，这可以通过诸如流体力显微镜（FluidFM）等技术来实现。后者能够将所需数据大小的实时确定与无人值守测量的高通量技术相结合，这将开辟新的分析领域。
