title: Nanochromatography driven by the coffee ring effect.
abstract: The coffee ring phenomenon has long been known for its ability to concentrate particles at the rim of a dried liquid droplet, yet little is known about its particle separation capability. Here, we elucidate the physics of particle separation during coffee ring formation, which is based on a particle-size selection mechanism near the contact line of an evaporating droplet. On the basis of this mechanism, we demonstrate nanochromatography of three relevant biological entities (proteins, micro-organisms, and mammalian cells) in a liquid droplet, with a separation resolution on the order of ∼100 nm and a dynamic range from ∼10 nm to a few tens of micrometers. These findings have direct implications for developing low-cost technologies for disease diagnostics in resource-poor environments.
authors.forename: Tak-Sing
authors.initials: TS
authors.lastname: Wong
authors.forename: Ting-Hsuan
authors.initials: TH
authors.lastname: Chen
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Shen
authors.forename: Chih-Ming
authors.initials: CM
authors.lastname: Ho
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002469:Cell Separation; D002845:Chromatography / Q000379:methods*; D003069:Coffee; D004926:Escherichia coli / Q000302:isolation & purification; D007074:Immunoglobulin G / Q000302:isolation & purification; D016393:Lymphoma, B-Cell / Q000473:pathology; D051379:Mice; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size
chemical_list: D003069:Coffee; D007074:Immunoglobulin G