Electronic Detection of DNA with Amorphous Silicon Nanostructures

We present the fabrication and characterization of a nano-scale sensor made of amorphous silicon (a-Si), functionalized for the detection of pH and DNA hybridization. The detector is composed of a nano-scale a-Si semicircle with a surface functionalized by receptor molecules containing single-strand DNA. Target complimentary DNA molecules bind the receptor molecules and their charge accumulating near the surface of the nanoscale semicircle causes in turn a change in the charge carrier density under the surface. This change of charge carrier density results in an effective change of conductance that can be monitored electronically. The sensor structure allows for direct conversion of molecular recognition and binding events to electronic signals.