Preparation of Silicon Nanowire Field-effect Transistor for Chemical and Biosensing Applications

Abstract

Surveillance using biomarkers is critical for the early detection, rapid intervention, and reduction in the incidence of diseases. In this study, we describe the preparation of polycrystalline silicon nanowire field-effect transistors (pSNWFETs) that serve as biosensing devices for biomarker detection. A protocol for chemical and biomolecular sensing by using pSNWFETs is presented. The pSNWFET device was demonstrated to be a promising transducer for real-time, label-free, and ultra-high-sensitivity biosensing applications. The source/drain channel conductivity of a pSNWFET is sensitive to changes in the environment around its silicon nanowire (SNW) surface. Thus, by immobilizing probes on the SNW surface, the pSNWFET can be used to detect various biotargets ranging from small molecules (dopamine) to macromolecules (DNA and proteins). Immobilizing a bioprobe on the SNW surface, which is a multistep procedure, is vital for determining the specificity of the biosensor. It is essential that every step of the immobilization procedure is correctly performed. We verified surface modifications by directly observing the shift in the electric properties of the pSNWFET following each modification step. Additionally, X-ray photoelectron spectroscopy was used to examine the surface composition following each modification. Finally, we demonstrated DNA sensing on the pSNWFET. This protocol provides step-by-step procedures for verifying bioprobe immobilization and subsequent DNA biosensing application. Video LinkThe video component of this article can be found at

Silicon Nanowire Field-Effect Transistor as Label-Free Detection of Hepatitis B Virus Proteins with Opposite Net Charges

“…The procedure of probe immobilization was confirmed again by measuring the electrical properties changes, which has been reported in a previous study [ 35 ]. As shown in Figure 3 , the electrical properties of pSiNWFET were measured following surface modification steps.…”

“…Surface modification and immobilization of antibodies on the devices is the first critical step that needs to be achieved for developing a biosensor. In this study, the surface modification and self-assembly antibodies on the device with amine and aldehyde linkers were adapted from the previous study [ 35 ]. The verification was analyzed using XPS ( Figure 2 ), which XPS is a powerful tool used to analyze surface chemistry [ 36 ].…”

Recent Advances of Field-Effect Transistor Technology for Infectious Diseases

“…This can be done through physical adsorption and chemical cross-linking [ 121 ]. After exposing the functionalized surface to the sample, an electric field is induced onto the NWs and changes their conductivity as a result of the interaction between the charged target and receptors [ 122 ]. Several types of biological interactions such as antibody–antigen, protein–ligand, and oligonucleotide hybridization can be inspected on the surface of NW-FET biosensors [ 123 ].…”

Point-of-care-ready nanoscale ISFET arrays for sub-picomolar detection of cytokines in cell cultures

“…In recent years, mechanical (quartz crystal microbalance), optical (fluorescence, colorimetric, photonic resonators, and Raman etc. ), and electrical (electrochemical, impedance and field-effect based) sensor platforms have been realized for label-free screening of cytokines [7][8][9][12][13][14][15][16][17][18][19][20][21][22]. Notably, localized surface plasmon resonance (LSPR)-based multi-arrayed biosensors were shown for label-free, real-time detection of IL-2, IL-4, IL-6, IL-10, TNF-α, and IFNγ from serum [9,23].…”

“…Most of the optical methods, however, still require expensive instrumentation and are not suitable for PoC integration [7,8,24]. Among electrical biosensors, onedimensional (1D) and two-dimensional (2D) ion-sensitive field-effect transistors (ISFETs) based on silicon (Si), graphene, and molybdenum disulfide (MoS 2 ) have been employed for detection of cytokines such as TNF-α, IL-1β, IL-6, and IL-8 [12,[25][26][27][28][29][30][31][32][33][34][35]. A comparative analysis (in terms of sensitivity and response time) of different electrical sensors realized for detection of cytokines in last 5 years is listed in Table 1.…”