Packing of stable and crack-free photonic crystals (PCs) into micro channels is a prerequisite for ideal separation, but often takes several days and many steps, including assembly and immobilization. This work was dedicated to finding a fast, one-step solution. Simply by heating and blowing away the vapor, the packing of silica PCs into micro channels by classic evaporation-induced assembly was greatly accelerated and could unite the immobilization into one step. An apt method was thus established, which was able to pack 2 cm PCs into microfluidic channels in 15 min, saving a lot of time. The packed PCs showed no evident cracks along the borders of their continuous domain, therefore they are capable of withstanding an anti-electrical field at 2000 V cm(-1) for 5 h and storage in water for 2 months. This enables ultra-fast separation of amino acids along a 2.5 mm PC in 4 s, and peptides along a 10 mm PC in 12 s. The separation was highly efficient and reproducible, with a 300 nm plate height and 0.24%-0.35% relative standard deviation of migration time. This one-step approach is extendable to other gelling particles, and the resulted stable, crack-free PCs would have large potential in ultra-fast separation of other analytes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.