Polysilicon Wire for the Detection of Label-Free DNA

Abstract

In this paper, we report the use of polysilicon (poly-Si) wire for label-free DNA sequence detection. Both single-strained (ss) homopolymers, polyadenine [poly(A)], polythymine [poly(T)], polycytosine [poly(C)], and polyguanine [poly(G)], and double-stranded (ds) heteropolymers (one homopolymer with its complement homopolymer), (A-T) [poly(A-T)] and (C-G) [poly(C-G)], were detected. These polymers, with different lengths and concentrations, were dropped onto the poly-Si wire surface, and then the currents flowing through the poly-Si wire channel were determined. The absolute value of the amount of current change in the channel for ss homopolymers with fixed length and fixed concentration is as follows: . For ds heteropolymers, it was observed that poly(A-T) has a that is higher than that of poly(C-G). This study also showed that the poly-Si wire is useful for detecting single- and multiple-base changes in the ss homopolymers as well as single- and multiple-matched-pair changes in ds heteropolymers. A single-pair mismatch in ds poly(C-G) was also investigated in this work.