Microstructured apertures in planar glass substrates for ion channel research

We have developed planar glass chip devices for patch clamp recording. Glass has several key advantages as a substrate for planar patch clamp devices. It is a good dielectric, is well-known to interact strongly with cell membranes and is also a relatively inexpensive material. In addition, it is optically neutral. However, microstructuring processes for glass are less well established than those for silicon-based substrates. We have used ion-track etching techniques to produce mum-sized apertures into borosilicate and quartz-glass coverslips. These apertures, which can be easily produced in arrays, have been used for high resolution recording of single ion channels as well as for whole-cell current recordings from mammalian cell lines. An additional attractive application that is greatly facilitated by the combination of planar geometry with the optical neutrality of the substrate is single-molecule fluorescence recording with simultaneous single-channel measurements.