Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA, USA.
Colloids Surf B Biointerfaces. 2013 Mar 1;103:59-66. doi: 10.1016/j.colsurfb.2012.09.043. Epub 2012 Oct 9.
Solute self-organization during evaporation of colloidal sessile droplets has attracted the attention of researchers over the past few decades due to a variety of technological applications. Recently, pattern formation during evaporation of various biofluids has been studied due to potential applications in screening and diagnosis. The complex morphological patterns in the deposit are unique to various disorders and are influenced by various physical mechanisms occurring during evaporation. These complex patterns can be better understood by studying evaporation of model solutions of biological relevance. Here, we examine the general features of pattern formation during sessile droplet evaporation of aqueous lysozyme solutions with varying concentrations of NaCl. Lysozyme is a globular protein found in biological fluids such as tears and saliva. The morphological evolution of the droplet is studied by time-lapse video during evaporation via reflection optical microscopy. The final deposits exhibit an amorphous peripheral ring and interior regions containing crystallites and dendritic forms, dependent on NaCl concentration. Scanning electron microscopy (SEM) images demonstrate the multi-scale hierarchical nature of these structures.
由于具有多种技术应用，过去几十年来，胶体液滴蒸发过程中的溶质自组织一直吸引着研究人员的注意。最近，由于在筛选和诊断方面的潜在应用，各种生物流体蒸发过程中的图案形成也得到了研究。由于各种物理机制在蒸发过程中发生，沉积物中的复杂形态图案是各种疾病所特有的。通过研究具有生物学相关性的模型溶液的蒸发，可以更好地理解这些复杂的图案。在这里，我们研究了不同浓度氯化钠的水溶液溶菌酶溶液液滴蒸发过程中图案形成的一般特征。溶菌酶是一种在生物体液（如眼泪和唾液）中发现的球形蛋白质。通过反射光显微镜在蒸发过程中进行时移视频，研究了液滴的形态演变。最终的沉积物表现出无定形的外围环和包含结晶和树枝状形式的内部区域，这取决于氯化钠浓度。扫描电子显微镜（SEM）图像证明了这些结构的多尺度层次性质。
