Anti- Functionalized Silver-Doped Carbon Nanofibers for Capture of in Microfluidic Systems.

Silver-doped carbon nanofibers (SDCNF) are used as the base material for the selective capture of in microfluidic systems. Fibers were spun in a glovebox with dry atmosphere maintained by forced dry air pumped through the closed environment. This affected the evaporation rate of the solvent during the electrospinning process and the distribution of silver particles within the fiber. Antibodies are immobilized on the surface of the silver-doped polyacrylonitrile (PAN) based carbon nanofibers via a three-step process. The negatively charged silver particles present on the surface of the nanofibers provide suitable sites for positively charged biotinylated poly-(l)-lysine-graft-poly-ethylene-glycol (PLL--PEG biotin) conjugate attachment. Streptavidin and a biotinylated anti- antibody were then added to create anti- surface functionalized (AESF) nanofibers. Functionalized fibers were able to immobilize up to 130 times the amount of on the fiber surface compared to neat silver doped fibers. Confocal images show remains immobilized on fiber mat surface after extensive rinsing showing the bacteria is not simply a result of non-specific binding. To demonstrate selectivity and functionalization with both gram negative and gram-positive antibodies, anti- surface functionalized (ASSF) nanofibers were also prepared. Experiments with AESF performed with () and ASSF with show negligible binding to the fiber surface showing the selectivity of the functionalized membranes. This surface functionalization can be done with a variety of antibodies for tunable selective pathogen capture.