DOI: 10.1039/c9an01962f
论文题名: Ultra-sensitive gas phase detection of 2,4,6-trinitrotoluene by non-covalently functionalized graphene field effect transistors
作者: Gajarushi A.S. ; Surya S.G. ; Walawalkar M.G. ; Ravikanth M. ; Rao V.R. ; Subramaniam C.
刊名: Analyst
ISSN: 32654
出版年: 2020
卷: 145, 期: 3 语种: 英语
英文摘要: The high energy density (4.2 MJ kg-1) and low vapour pressure (7.2 × 10-9 atm) of chemical explosives such as TNT (2,4,6-trinitrotoluene) pose a grave security risk demanding immediate attention. Detection of such hazardous and highly challenging chemicals demands specific, ultra-sensitive and rapid detection platforms that can concomitantly transduce the signal as an electrical readout. Although chemo-sensitive strategies have been investigated, the majority of them are restricted to detecting TNT from solutions and are therefore not implementable in real-time, on-field situations. Addressing this demand, we report an ultra-sensitive (parts-per-billion) and rapid (∼40 s) detection platform for TNT based on non-covalently functionalized graphene field effect transistors (GFETs). This multi-parametric GFET detector exhibits a reliable and specific modulation in its Dirac point upon exposure to TNT in the vapour phase. The chemical specificity provided by 5-(4-hydroxyphenyl)-10,15,20-tri(p-tolyl) zinc porphyrin (ZnTTPOH) is synergistically combined with the high surface sensitivity of graphene through a non-covalent functionalization approach to realise p-doped GFETs (Zn-GFETs). Such a FET platform exhibits extremely sensitive shifts in Dirac point (ΔDP) that correlate with the number of nitro groups present in the analyte. Analytes with mono-, di-, and tri-nitro substituted aromatic molecules exhibit distinctly different ΔDP, leading to unprecedented specificity towards TNT. Additionally, the Dirac point of Zn-GFETs is invariant for common and potential interferons such as acetone and 2-propanol (perfume emulsifiers) thereby validating their practical applicability. Furthermore, the ΔDP is also manifested as changes in the contact potential of GFETs, indicating that sub-monolayer coverage of ZnTTPOH is sufficient to modulate the transfer characteristics of GFETs over an area 1000 times larger than the dopant dimensions. Specifically, ZnTTPOH-functionalized GFETs exhibit p-doped behaviour with positive ΔDP with respect to pristine GFETs. Such p-doped Zn-GFETs undergo selective charge-transfer mediated interactions with TNT resulting in enhanced electron withdrawal from Zn-GFETs. Thus the ΔDP shifts to a higher positive gate voltage leading to the dichotomous combination of the highest signal generation (1.2 × 1012 V mol-1) with ppb level molecular sensitivity. Significantly, the signal generated due to TNT is 105 times higher in magnitude compared to other potential interferons. The signal reliability is established in cross-sensitivity measurements carried out with a TNT-mDNB (1:10 molar ratio) mixture pointing to high specificity for immediate applications under atmospherically relevant conditions pertaining to homeland security and global safety. © 2020 The Royal Society of Chemistry.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/159353
Appears in Collections: 气候变化与战略
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作者单位: Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India; Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India; Indian Institute of Technology Delhi HauzKhas, New Delhi, 110 016, India
Recommended Citation:
Gajarushi A.S.,Surya S.G.,Walawalkar M.G.,et al. Ultra-sensitive gas phase detection of 2,4,6-trinitrotoluene by non-covalently functionalized graphene field effect transistors[J]. Analyst,2020-01-01,145(3)