Colorimetric Sensor Based on Self‐Assembled Polydiacetylene/Graphene‐Stacked Composite Film for Vapor‐Phase Volatile Organic Compounds

Abstract

A portable litmus‐type chemosensor is developed for the effective detection of environmentally hazardous volatile organic compounds (VOCs) using polydiacetylene (PDA) and graphene stacked within a composite film. The graphene is exploited as a transparent and efficient supporter for the highly ordered PDA monolayer. This colorimetric sensor exhibits a sensitive response to low concentrations of VOCs (∼0.01%), including tetrahydrofuran (THF), chloroform (CHCl3), methanol (CH3OH), and dimethylformamide (DMF). The color change that is caused by relatively high concentrations of VOCs can be perceived by the naked eye, and it is noteworthy that a logarithmic relationship is observed between the chromatic response and the VOC concentration in the range of ∼0.01%–10%. The structural conformation changes of the PDA molecules, caused by interactions with VOCs, are directly observed by scanning tunneling microscopy (STM), which reveals the intrinsic mechanism of the chromatic variety at the molecular level.

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

“…[9,10] Recently, considerable effort has been devoted to developing much simpler routes to control the shape and grain size of SMO to achieve a higher surface-to-area ratio and unique surface chemistry behavior to improve sensing performance. [11][12][13] Among the metal oxides, molybdenum trioxide (MoO 3 ) is one of the most desirable for use in gas sensors because of its indirect wide band gap of 3.5 eV. [14][15][16][17] MoO 3 -based gas analyzing devices show excellent gas sensing properties for several kinds of gas species [18][19][20][21][22][23][24] because of their special quantum size effect, surface effect, high reactivity, and the polyvalency of molybdate.…”

Mechanically Drawable Thermochromic and Mechanothermochromic Polydiacetylene Sensors

“…Importantly, blue colored PDAs undergo a color change to red when they are exposed to various chemical (e.g., volatile organic solvents, ions, and specifi c molecular recognition events) and physical (e.g., temperature and mechanical strain) stimuli. Stimulus-responsive colorimetric PDAs have been prepared in a variety of forms including aqueous suspensions, [24][25][26]33,43,44 ] fi lms, [13][14][15][16][17]31 ] nanowires/nanofi bers, [ 19,45,46 ] microarrays, [ 28,29,47 ] and microfl uidic chips. [ 48 ] In the investigation described below, we prepared a new crayon-like PDA-wax composite by using a mixing-molding technique.…”

Sensor for volatile organic compounds using an interdigitated gold electrode modified with a nanocomposite made from poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and ultra-large graphene oxide

“…S5c,d, ESM). Compared with the recent literatures (see Table 1) on methanol gas detection at room temperature [28][29][30][31][32][33][34][35], the as-prepared optimized PEDOT-PSS/UL-GO nanocomposite gas sensor in this work showed the best sensitivity and the fastest response. The enhanced methanol Poly(methyl methacrylate)/CNT 100,000-1,000,000 ppm~18 for 100,000 ppm~120~400 [30] PEDOT-PSS/Nanowire 100,000-500,000 ppm 3 for 200,000 ppm~30~30 [31] Chitosan/CNT 0-10,000 ppm~11 for 1000 ppm 600~360 [32] Reducer graphene oxide (RGO)/ poly(ionic liquid) (PIL)-PEDOT [35] sensing properties of optimized PEDOT-PSS/UL-GO nanocomposite gas sensor may be attributed to (I) improvement the formation of the linear and extended-coil conformation of PEDOT and PSS chains and increase of the surface roughness as shown in Fig.…”