Shift of isoelectric point in extended nanospace investigated by streaming current measurement

Isoelectric points in extended nanochannels (580-2720 nm) fabricated on fused-silica substrates were measured using the streaming current method. The isoelectric point obtained in a 2720 nm channel was almost the same as the isoelectric point reported for the bulk (2.6-3.2). However, the isoelectric point in the extended nanochannel (580 nm) was decreased to less than 2.0. This result provides important information for the modeling of ion transport in extended nanospace. © 2011 American Institute of Physics.