Tungsten Disulfide Nanosheet-Based Field-Effect Transistor Biosensor for DNA Hybridization Detection

Abstract

Transition-metal dichalcogenides (TMDs), including molybdenum disulfide (MoS2) and tungsten disulfide (WS2), with appealing properties have recently become promising alternatives to graphene with semimetal and low on/off current ratio properties as the sensing channel in field-effect transistor (FET) biosensors. However, the efficiency of DNA-based FET devices strongly depends on how DNA probes are tethered to the nanomaterial channels. As against covalent attachment, simple DNA physisorption has become increasingly popular, and a DNA sequence with strong affinity for nanomaterials is still highly sought after. Recently, poly-cytosine (poly-C) DNA was found to be strongly adsorbed to many common nanomaterials, including WS2. Herein, a diblock DNA probe containing a (poly-C) (C15) was used to attach to a chemical vapor deposition (CVD)-grown monolayer WS2 surface; meanwhile, the target complementary DNA (cDNA) was hybridized to the other block of the DNA probe. The biosensor developed following this strategy led to a limit of detection down to 3 aM within a concentration range spanning over approximately 7 orders of magnitude (10–16 to 10–9 M), which was lower than those of the previously reported TMDs and a good competitor to graphene FET DNA biosensors. Moreover, the proposed WS2 FET DNA biosensor showed high specificity capable of distinguishing the cDNA from non-cDNA, one-base mismatched DNA, two-base mismatched DNA, and three-base mismatched DNA, making our strategy an exciting avenue for disease diagnosis. The authors are convinced that this work extends the CVD synthesis of WS2 and its promise in biosensing application-based FETs.

Toward selective transfer of CVD monolayer WS2 based on laser-cutting dedicated FET applications

“…The thickness of the triangular shape of WS 2 was characterized via AFM (Figure 3.b). The corresponding high of the obtained AFM following the cross-sectional (white line) was presented in Figure 3.c, verifying a monolayer WS 2 crystals structure with a thickness of 0.8 nm, which is in good agreement with previously reported works [2]. Figure 2.e shows the Raman spectra plot ranging from 250 to 450 cm -1 .…”

“…The obtained peaks position, intensity ratio, and the difference between the two characteristics peak are further confirming that the obtained structure is monolayer WS 2 crystals [2], [3], [15]. Figure 3.f displays the PL spectrum of WS 2 with a strong and asymmetric shape peak centered at 633.2 nm, which corresponds to the direct band gap of about 1.96 eV of the single-layer WS 2 crystal which is also consistent with previously reported CVD grown WS 2 [10].…”

“…Monolayer tungsten disulfide (WS 2 ) with its direct bandgap and attractive optical properties, opens up the possibility of widespread integration in photodetectors electroluminescent devices, integrated circuits, and transistors [1], [2]. Chemical vapor deposition (CVD) [3] possess the advantage of large-area WS 2 growth compared to other synthesis methods like liquid exfoliation and mechanical cleavage [4].…”

“…However, recent studies have shown that CVD has grown WS 2-based FET displays only 0.01 to 20 cm 2 V -1 s -1 and only when sandwiched between hexagonal boron nitride (hBN) films exhibit high field-effect mobility (~ 200 cm 2 V -1 s -1 ) and high ON/OFF ratio (~ 10 7 ) at room temperature [9]. Nowadays, tungsten disulfide-based devices still need to be integrated with today's low-cost and well-known CMOS technology to develop WS 2 -based integrated electronic appliances [2]. Such integration supplies the mixture of mature silicon technology functions and WS 2 on a single chip [5].…”

Fabrication and Functionalisation of Nanocarbon‐Based Field‐Effect Transistor Biosensors

“…In 2 O 3 [30] Side gate Chemical Enzyme I ds À V g 10 nM Si nanowire [31] Liquid gate Ion Chemical receptor I ds À V g 10 μM ITO nanowire [32] Bottom gate DNA Complementary DNA I ds À V g 1 fM MoS 2 [33] Bottom gate Protein Antibody I ds À V g 1 ng/L WS 2 [34] Bottom gate DNA Complementary DNA I ds À V g 3 aM…”