High resolution separation by pressure-driven liquid chromatography in meander extended nanochannels

The rapidly developing interest in nanofluidics, which is used to examine liquids on an order that ranges from an attoliter to a femtoliter, correlates with the recent interest in decreased sample amounts, such as in the field of single-cell analysis. In this paper, we have succeeded in the normal phase separation of a 101 fL sample with a high number of theoretical plates (103 plates), and a fast separation (4 s), using a pressure-driven flow in extended nanochannels. A meander separation channel 1 μm wide was introduced and showed no band broadening at the turns, unlike microchannels (101–102 μm wide), which is an important aspect in order to lengthen the channel in a space-limited micro/nanofluidic chip. Our device enables the fast separation of an ultra-small volume of sample with a high number of theoretical plates, and will serve as a general platform for the separation of aL to fL volumes of samples.

► Chip based separation in normal phase mode was achieved in extended nanochannels.
► Theoretical plates of 103 were achieved within 4 s, with fL injection volume.
► Band broadening at turns was not observed in 1 μm wide meander separation channel.
► Thin meander channels can be used to lengthen the separation channel.