On the Development of Label-Free DNA Sensor Using Silicon Nanonet Field-Effect Transistors

In this paper, the process and electrical characteristics of DNA sensor devices based on silicon nanonet (SiNN) field-effect transistors are reported. The SiNN, another name of randomly oriented Si nanowires network, was successfully integrated into transistor as p-type channel using standard microelectronic technology. The SiNN-based transistors exhibit a high initial ON-state current (5.10−8 A) and homogeneous electrical characteristics. For DNA detection, a new and eco-friendly functionalization process based on glycidyloxypropyltrimethoxysilane (GOPS) was performed which enables the covalent grafting of DNA probes on SiNN. This hybridization leads to a significant decrease of ON-state current of device. Additionally, it is observed that SiNN devices reveal reproductive current response to DNA detection. We demonstrate, for the first time, the successful integration of SiNN into sensor for electrical label-free DNA detection at low cost.