Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

Abstract

Aromatic volatile organic compound (VOC) sensors are attracting growing interest as a response to the pressing market need for sensitive, fast response, low power consumption and stable sensors. Benzene and toluene detection is subject to several potential applications such as air monitoring in chemical industries or even biosensing of human breath. In this work, we report the fabrication of a room temperature toluene and benzene sensor based on multiwall carbon nanotubes (MWCNTs) decorated with gold nanoparticles and functionalised with a long-chain thiol self-assembled monolayer, 1-hexadecanethiol (HDT). High-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR) were performed to characterize the gold nanoparticle decoration and to examine the thiol monolayer bonding to the MWCNTs. The detection of aromatic vapours using Au-MWCNT and HDT/Au-MWCNT sensors down to the ppm range shows that the presence of the self-assembled layer increases the sensitivity (up to 17 times), selectivity and improves the response dynamics of the sensors.

Metal Oxide Nanoparticle-Decorated Few Layer Graphene Nanoflake Chemoresistors for the Detection of Aromatic Volatile Organic Compounds

“…This heating was obtained by applying an external voltage (one volt) to a heating element printed on the backside of the sensor substrate and helps desorbing vapor molecules from the graphene surface. The same behavior has been observed in a previous research in which carbon nanotubes were used [ 43 ]. This strategy of heating was applied only once to show its effect, but all the measurements shown in Figure 4 were performed at room temperature and no heating was used to help regain the baseline.…”

“…Table 2 summarizes a comparison between the performance in the detection of BTX vapors reported here and previously published results. The normalized response of our metal oxide-decorated graphene sensors show higher values for xylene and toluene vapors than those reported in previously published results [ 3 , 41 , 42 , 43 , 54 ]. Mirzaei and co-workers report in their review [ 3 ] a ZnO nanowire sensor modified with small amounts of reduced graphene oxide (rGO) with a remarkably high response to benzene vapors.…”

Carbon Nanostructure Embedded Novel Sensor Implementation for Detection of Aromatic Volatile Organic Compounds: An Organized Review

“…The ability of Au-MWCNT and HDT/Au-MWCNT sensors to detect VOCs at levels as low as ppm is evidence that the self-assembled layer enhances the sensing selectivity, sensitivity by a factor of 17, and response dynamics. The response of the Au-MWCNT sensor to various vapor injection amounts for toluene and benzene at room temperature is shown in Figure a,b …”

Pt-, Rh-, Ru-, and Cu-Single-Wall Carbon Nanotubes Are Exceptional Candidates for Design of Anti-Viral Surfaces: A Theoretical Study

“…In order to develop a filter with a long shelf-life, it is crucial to ensure that peroxide and subsequently the virus can be retained by the CNT filter. Functionalization of SWCNTs with transition metals not only help to destroy the virus but also enhance the interactions between the sensing material and the target molecule thanks to their strong catalytic performance [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ].…”