Thermoplastics have become attractive alternatives to glass/quartz for microfluidics, but the realization of thermoplastic nanofluidic devices has been slow in spite of the rather simple fabrication techniques that can be used to produce these devices. This slow transition has in part been attributed to insufficient understanding of surface charge effects on the transport properties of single molecules through thermoplastic nanochannels. We report the surface modification of thermoplastic nanochannels and an assessment of the associated surface charge density, zeta potential and @entity450 ( @entity450 ). Mixed-scale fluidic networks were fabricated in @entity4625 , @entity4625 . @entity26 plasma was used to generate surface-confined @entity7574 with devices assembled using low temperature fusion bonding. Amination of the carboxylated surfaces using @entity9373 (EDA) was accomplished via EDC coupling. XPS and ATR-FTIR revealed the presence of carboxyl and @entity6115 groups on the appropriately prepared surfaces. A modified conductance equation for nanochannels was developed to determine their surface conductance and was found to be in good agreement with our experimental results. The measured surface charge density and zeta potential of these devices were lower than glass nanofluidic devices and dependent on the surface modification adopted, as well as the size of the channel. This property, coupled to an apparent increase in fluid viscosity due to nanoconfinement, contributed to the suppression of the @entity450 in @entity4625 nanofluidic devices by an order of magnitude compared to the micro-scale devices. Carboxylated @entity4625 nanochannels were efficient for the transport and elongation of   -DNA while these same DNA molecules were unable to translocate through aminated nanochannels.

Surface charge, XXXX and DNA extension in chemically modified thermoplastic nanoslits and nanochannels.

@entity4625 :: ('MESH:D019904', 'Chemical') :: ['PMMA', 'poly(methylmethacrylate)'] @entity9373 :: ('MESH:C031234', 'Chemical') :: ['ethylenediamine'] @entity7574 :: ('MESH:D002264', 'Chemical') :: ['carboxylic acids'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['Oxygen'] @entity6115 :: ('CHEBI:32952', 'Chemical') :: ['amine'] @entity450 :: ('MESH:D006940', 'Disease') :: ['electroosmotic flow', 'EOF']
@entity450 :: (MESH:D006940,Disease) :: ['electroosmotic flow']
