Meniscus-Directed Assembly of Biologically Active Coatings of Cells, Microparticles, and Nanoparticles

nanoparticle;cell coating;colloid

Stamm, Lindsey Brooks Jerrim ; Orlin Velev, Committee Chair,Anne Lazarides, Committee Member,Jan Genzer, Committee Member,Christine Grant, Committee Member,Carol Hall, Committee Member,Stamm, Lindsey Brooks Jerrim ; Orlin Velev ; Committee Chair ; Anne Lazarides ; Committee Member ; Jan Genzer ; Committee Member ; Christine Grant ; Committee Member ; Carol Hall ; Committee Member

University:North Carolina State University

关键词: nanoparticle;    cell coating;    colloid;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/3552/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

Convective assembly principles and techniques were used in two complementarystudies for depositing close packed yeast-coated surfaces and gold nanoparticle wires.Convective assembly at high volume fraction was used for the rapid deposition ofuniform, close-packed coatings of Saccharomyces cerevisiae onto glass slides. Acomputational model was developed to calculate the thickness profiles of such coatingsfor various experimental conditions. Both experimentation and numerical simulationsdemonstrated that the deposition process is strongly affected by the presence ofsedimentation. The deposition device was inclined to increase the uniformity of thecoatings by causing the cells to sediment toward the three-phase contact line. Inaccordance with the simulation, the experiments showed that both increasing the angle ofthe device and decreasing the angle between the slides increased the uniformity of thedeposited coatings. Finally, the “convective-sedimentationâ€Âassembly method was usedto deposit composite coatings of live cells and large latex particles as an example ofbiologically active composite coatings. These coatings were allowed to proliferate anddemonstrate a proof-of-concept of a self-cleaning surface.Two methods were developed for the deposition of micro- and nanoparticles intolinear assemblies that could be used in biosensors and biomaterials. In capillary-guideddeposition, a capillary is withdrawn across a wettable substrate, resulting in the assemblyof a particle line. We characterized the effects of particle concentration and withdrawalspeed and correlated them to structure of the deposited assemblies. The particles areassembled into one of three different structures, depending on the particle volumefraction and deposition speed. We demonstrate that the metallic nanoparticle lines areOhmically conductive. Using wedge-templated deposition, linear assemblies weredeposited from sessile droplets on moderately hydrophobic surfaces. The particlesconvectively assemble at the freely-receding three-phase contact line and are pulled into aline against the wedge. The deposited lines can be long and narrow with a few breaks orsignificantly wider and shorter but unbroken. These methods could be used forengineered patterning of nanoparticle structures on surfaces.