DNA Sensing by Silicon Nanowire: Charge Layer Distance Dependence

Abstract

To provide a comprehensive understanding of the field effect in silicon nanowire (SiNW) sensors, we take a systematic approach to fine tune the distance of a charge layer by controlling the hybridization sites of DNA to the SiNW preimmobilized with peptide nucleic acid (PNA) capture probes. Six target DNAs of the same length, but differentiated successively by three bases in the complementary segment, are hybridized to the PNA. Fluorescent images show that the hybridization occurs exclusively on the SiNW surface between the target DNAs and the PNA. However, the field-effect response of the SiNW sensor decreases as the DNA (charge layer) moves away from the SiNW surface. Theoretical analysis shows that the field effect of the SiNW sensor relies primarily on the location of the charge layer. A maximum of 102% change in resistance is estimated based on the shortest distance of the DNA charge layer (4.7 A) to the SiNW surface.

Silicon nanowire-transistor biosensor for study of molecule-molecule interactions

“…To investigate the field effect in SiNW sensor, we first designed an approach to vary the distance of the charge layer away from the sensing surface by tuning the binding sites of DNA-PNA hybridization while maintaining charges constant (Zhang et al 2008). The recorded results showed that the detection sensitivity was distance dependent that agreed well with the theoretical analysis.…”

Sensing at the Surface of Graphene Field‐Effect Transistors

“…I). [74][75][76][77]80] At the end of this review, we will discuss in details that recent progresses on operating GFETs at high frequencies suggested that Debye screening can be overcome: [46] 1.…”

“…Possible routes to circumvent the Debye screening effect include short antibody design, porous polymer incorporation, and ex situ measurement in low ionic strength buffers (see Section 2.5). [74][75][76][77]80] These approaches, however, also impose limitations on the biodetection and it is highly desirable to develop a straightforward methods to overcome the Debye screening: [46] 1. without any special design or engineering of the receptor molecules and the sensor environments, and 2. in physiological conditions to facilitate in-situ, real-time biosensing. Theoretically, improved sensitivity is expected at high frequencies using a measuring strategy that overcomes the ionic screening effect.…”

Thermal transport in nanostructures

“…In addition to CNTs, Silicon nanowires (SiNWs) have attracted a great attention in recent years because of their excellent physical and chemical properties, and their potential applications in many areas including biosensor, 65,66 electronic device, 67,68 and solar photovoltaics. 69,70 SiNWs are appealing choice due to their ideal interface compatibility with conventional Si-based devices.…”