Electrical Characterization of Sequence-specific Label-free DNA by using Polysilicon Wire

Abstract

In this paper we report the electrical measurement of sequence-specific and label-free deoxyribonucleic acid (DNA) by using poly-silicon (poly-Si) wire. Four single-strained (ss) DNA bases, adenine (A), thymine (T), cytosine (C) and guanines (G), as well as double-stranded (ds) DNA sequences, ds(A-T) and ds(C-G), with different lengths and concentrations were dropped onto the poly-Si wire surface, and currents flowing through the poly-Si wire channel were determined. It is found that the amount change of the channel current ΔI for ssDNAs with fixed length and fixed concentration is that T > C > G > A. For dsDNA sequence, we observe that ds(A-T) has higher ΔI than does ds(C-G). We also prove that single base change in ssDNA is feasible by using the poly-Si wire sensor.