Thousandfold signal increase using field-amplified sample stacking for on-chip electrophoresis.
Field-amplified sample stacking (FASS) leverages conductivity gradients between a volume of injected sample and the background buffer to increase sample concentration. A major challenge in applying FASS to on-chip assays is the initial setup of high-conductivity gradient boundaries in the region of the injected sample volume. We have designed, fabricated, and characterized a novel FASS-capillary electrophoresis (CE) chip design that uses a photoinitiated porous polymer structure to facilitate sample injection and flow control for high-gradient FASS. This polymer structure provides a region of high flow resistance that allows the electromigration of sample ions. We have demonstrated an electropherogram signal increase by a factor of 1100 in electrophoretic separations of fluorescein and Bodipy with, respectively, 2 microM and 1 microM initial concentrations.
Department of Mechanical Engineering, Stanford University, CA 94305, USA. bsjung@stanford.edu
Byoungsok
B
Jung
Rajiv
R
Bharadwaj
Juan G
JG
Santiago
D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D007091:Image Processing, Computer-Assisted; D008904:Miniaturization / Q000295:instrumentation*; D011108:Polymers; D016062:Porosity
D011108:Polymers