Fabrication of 1D nanochannels with thin glass wafers for single molecule studies

1D nanochannels are fabricated by direct bonding of a silicon wafer, containing nanochannels, microchannels and access holes with a 170 μm thick and 100 mm diameter glass wafer. The thin glass wafers are used as channel covers because of their appropriate thickness for use with coverglass corrected water immersion lenses. As the nanochannel chips are used on an inverted microscope, access holes are created in the silicon wafer. It was found that polyimide is a good material for protection of the channel structures during deep reactive ion etching of the macro holes. Fabricated nanochannels with 50 nm depth were successfully filled with low concentrations of Alexa 488 solution which could be observed by fluorescence microscopy. These nanochannels are promising for mobility studies at the single molecule level.