Nanowire Transistor‐Based Ultrasensitive Virus Detection with Reversible Surface Functionalization

Abstract

We have applied a reusable silicon nanowire field-effect transistor (SiNW-FET) as a biosensor to conduct ultrasensitive detection of H5N2 avian influenza virus (AIV) in very dilute solution. The reversible surface functionalization of SiNW-FET was made possible using a disulfide linker. In the surface functionalization, 3-mercaptopropyltrimethoxysilane (MPTMS) was first modified on the SiNW-FET (referred to as MPTMS/SiNW-FET), with subsequent dithiothreitol washing to reduce any possible disulfide bonding between the thiol groups of MPTMS. Subsequently, receptor molecules could be immobilized on the MPTMS/SiNW-FET by the formation of a disulfide bond. The success of the reversible surface functionalization was verified with fluorescence examination and electrical measurements. A surface topograph of the SiNW-FET biosensor modified with a monoclonal antibody against H5N2 virus (referred to as mAb(H5)/SiNW-FET) after detecting approximately 10(-17) M H5N2 AIVs was scanned by atomic force microscopy to demonstrate that the SiNW-FET is capable of detecting very few H5N2 AIV particles.

Investigation into the Effect of Varied Functional Biointerfaces on Silicon Nanowire MOSFETs

“…In addition, above 2-fold signal changes on unmodified and APTMS-modified NW-MOSFETs were discovered in comparison with MPTMS modified NW-MOSFETs. It has been demonstrated that MPTMS-SAM modified on silicon NW-MOSFETs might form disulfide bonding between the mercapto groups of MPTMS [21]. As a consequence of the lower number of mercaptan groups of MPTMS on NWs, relatively minor signal responses to varied pH solutions are seen in Figure 2.…”

“…Furthermore, pH 2 solution protonated the surface of APTMS-modified NW-MOSFETs and resulted in significantly increasing voltage change in p-type devices [4]. Relatively smaller signal of MPTMS-modified NWs may be attributed to less well-ordered functional mercapto groups [21] and rather hydrophobic property [23]. The experiment of pH sensing showed our MOSFETs well performed in normal PBS.…”

“…In comparison with MPTMS, APTMS could form an approximately uniform SAM on the silicon surface and provide functional amino (-NH 2 ) groups [8] for later immobilizing relatively high amounts of biomolecules in Figure 6(d). In Figure 6(c), lower amount of MPTMS might be attributed to the formation of disulfide bonding between the mercapto groups of MPTMS [21]. Those disulfide bonds further influenced the organization of MPTMS-SAM on the surface.…”

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

“…Such work revealed the potential for the simultaneous detection of multiple viruses at the single virus level. In addition, an ultrasensitive detection of H5N2 avian influenza virus (AIV) has been realized by using a strategy of reversible surface functionalization of SiNW-FET in a dilute solution (Chiang et al 2012). A disulfide linker that reversibly controls the surface modification of SiNW renders the SiNW-FET a reusable device for the fast detection of H5N2 AIV.…”

High sensitive detections of Norovirus DNA and IgG by using multi-SiNW-FET biosensors

“…By modifying the SiNW-FET surface with specific functional molecules [2], previous works have shown the high sensitivity of SiNW-FET in measuring pH [3], and detecting proteins [4], DNA [5], and even single virus particles [6]. In the research of Kim, the SiNW-FETs was transformed into a DNA detector by modifying the SiNW-FETs surface with 3aminopropyltriethoxysilane (APTES) to provide a biochemical probe layer on the SiNWs [4].…”