Micro & Nano-scale Transport Laboratory, Waterloo Institute for Nanotechnology, Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Langmuir. 2021 Feb 2;37(4):1588-1595. doi: 10.1021/acs.langmuir.0c03365. Epub 2021 Jan 17.
Adhesion behavior of microbial pathogens on commonly encountered surfaces is one of the most pertinent questions now. We present the characterization of bacteria-laden droplets and quantify the adhesion forces on highly repellent surfaces with the help of a simple experimental setup. Comparing the force signature measured directly using an in-house capillary deflection-based droplet force apparatus, we report an anomalous adhesion behavior of live bacteria ()-laden droplets on repellent surfaces, which stands in stark contrast to the observed adhesion signature when the doping agent is changed to inert microparticles or the same bacteria in an incapacitated state. We showed that the regular contact angle measurements using optical goniometry is unable to differentiate between the live bacteria and the dead ones (including microparticles) and thus delineate its limitations and the complementary nature of the adhesion measurements in understanding the fundamental interfacial interaction of living organisms on solid surfaces.
微生物病原体在常见表面上的黏附行为是目前最为关注的问题之一。我们介绍了带菌液滴的特性，并借助简单的实验装置对高斥力表面上的黏附力进行了定量分析。通过与基于内部毛细管偏折的液滴力仪直接测量的力信号进行比较，我们报告了带活细菌的液滴在疏液表面上异常的黏附行为，这与当掺杂剂变为惰性微粒子或处于失活状态的相同细菌时观察到的黏附信号形成鲜明对比。我们表明，使用光学接触角测量法的常规接触角测量无法区分活细菌和死细菌（包括微粒子），因此阐明了其局限性以及在理解活生物体在固体表面上的基本界面相互作用方面，黏附测量的互补性。
