New approach towards imaging lambda-DNA using scanning tunneling microscopy/spectroscopy (STM/STS)

摘要

A new methodology to anchor lambda-DNA to silanized n-Si(lll) surface using Langmuir Blodget trough was developed. The n-Si (111) was silanized by treating it with low molecular weight octyltrichlorosi-lane in toluene. Scanning tunneling microscopy (STM) image of lambda-DNA on octyltrichlorosilane deposited Si substrate shows areas exhibiting arrayed structures of 700 nm length and 40 nm spacing. Scanning tunneling spectroscopy (STS) at different stages depict a broad distribution of defect states in the bandgap region of n-Si(lll) which presumably facilitates tunneling through otherwise insulating DNA layer.