Enhanced Sensing of Nucleic Acids with Silicon Nanowire Field Effect Transistor Biosensors

Abstract

Silicon nanowire (SiNW) field effect transistors (FETs) have emerged as powerful sensors for ultrasensitive, direct electrical readout, and label-free biological/chemical detection. The sensing mechanism of SiNW-FET can be understood in terms of the change in charge density at the SiNW surface after hybridization. So far, there have been limited systematic studies on fundamental factors related to device sensitivity to further make clear the overall effect on sensing sensitivity. Here, we present an analytical result for our triangle cross-section wire for predicting the sensitivity of nanowire surface-charge sensors. It was confirmed through sensing experiments that the back-gated SiNW-FET sensor had the highest percentage current response in the subthreshold regime and the sensor performance could be optimized in low buffer ionic strength and at moderate probe concentration. The optimized SiNW-FET nanosensor revealed ultrahigh sensitivity for rapid and reliable detection of target DNA with a detection limit of 0.1 fM and high specificity for single-nucleotide polymorphism discrimination. In our work, enhanced sensing of biological species by optimization of operating parameters and fundamental understanding for SiNW FET detection limit was obtained.

Simultaneous Tunable Selection and Self-Assembly of Si Nanowires from Heterogeneous Feedstock

“…for chemical/biological sensing applications and their ability to be solution-processed and assembled from "semiconducting inks" using various alignment techniques, make them potential key building blocks for the manufacturing of chemical and biological sensors, [1][2][3] high performance field-effect transistors (FETs), [4][5][6] optical devices, 7,8 memory elements [9][10][11] and energy harvesting. 12,13 The availability of high quality semiconducting NWs in scalable quantities remains one of the main challenges for NW-based printed electronics.…”

Label-Free Direct Detection of MiRNAs with Poly-Silicon Nanowire Biosensors

“…In general, the PNA-functionalized SiNW device is capable of generating higher change than the DNA-functionalized SiNW device does because DNA is negatively charged, thereby decreasing the signal-to-noise ratio. However, considering the much higher cost of PNA probes, we decided to use DNA probes as others did [19][20][21][22]. In general, it is better to use low salt buffer in SiNW because high ion concentration may cause contamination.…”

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

“…This nanodevice is capable of simultaneous recording of two virus DNA sequences, H1N1 and H5N1. Subsequently, the same group presented an enhanced sensitivity of sensing target DNA by using a back-gated SiNW-FET that has a triangle cross-section of nanowire functionalized with DNA probes and realized a detection limit of 0.1 fM of DNA molecules and high specificity of SNP discrimination (Gao et al 2012). In order to further improve the sensitivity of the nanoFET sensor, they employed rolling circle amplification (RCA) for electrical signal augmentation ( Figure 8B) (Gao et al 2013).…”

“…In addition, SiNW-FETs can perform rapid, ultrasensitive, and multiplexed detection of the desired targets independent of any labels (Patolsky et al 2006a, Gao et al 2007). In the past decade, this nanobiosensor has been widely used to detect a variety of molecule binding events with sensitivities below picomolar concentrations (Gao et al 2011(Gao et al , 2012(Gao et al , 2013. Because of the broad implementation of SiNW biosensor in molecule-molecule interactions and an extendable application in real-time in vivo monitoring (Tian et al 2010, Duan et al 2012a, Qing et al 2014, we summarize the recent advances in SiNWFETs with emphasis on a variety of molecule interactions.…”