Highly passivated silicon chips with micron aperture for the pA measurements of single ion channels

Detection of single channel activities in the pA range on a high throughput screening (HTS) device is of major interest for pharmaceutical industries developing new drugs targeting ion channels. A silicon chip, with 9 silicon membranes having a micron aperture each, was functionalized and characterized with ion channels. The reduced size of the aperture has the advantage to be compatible with the formation of a solvent-free bilayer, thus protecting the functional activity of the integrated membrane proteins. The highly passivated silicon chip with a 7 µm thick SiO2 TEOS and a 1 µm SiO2 PECVD reduced the intrinsic capacitive noise of the material, resulting in a measured current noise of 0.56 pA rms at 1 kHz low pass filter. The sensitivity of the recordings on the chips was validated by the detection of small conductance ion channels.