title: Tunable volatile organic compounds sensor by using thiolated ligand conjugation on MoS2.
abstract: One of the most important issues in the development of gas sensors for breath analysis is the fabrication of gas sensor arrays that possess different responses for recognizing patterns for volatile organic compounds (VOCs). Here, we develop a high-performance chemiresistor with a tunable sensor response and high sensitivity for representative VOC groups by using molybdenum disulfide (MoS2) and by conjugating a thiolated ligand (mercaptoundecanoic acid (MUA)) to MoS2 surface. Primitive and MUA-conjugated MoS2 sensing channels exhibit distinctly different sensor responses toward VOCs. In particular, the primitive MoS2 sensor presents positive responses for oxygen-functionalized VOCs, while the MUA-conjugated MoS2 sensor presents negative responses for the same analytes. Such characteristic sensor responses demonstrate that ligand conjugation successfully adds functionality to a MoS2 matrix. Thus, this will be a promising approach to constructing a versatile sensor array, by conjugating a wide variety of thiolated ligands on the MoS2 surface. Furthermore, these MoS2 sensors in this study exhibit high sensitivity to representative VOCs down to a concentration of 1 ppm. This approach to fabricating a tunable and sensitive VOC sensor may lead to a valuable real-world application for lung cancer diagnosis by breath analysis.
authors.affiliation: Department of Chemical and Biomolecular Engineering (BK-21 plus), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, , Daejeon 305-701, Korea.
authors.forename: Jong-Seon
authors.initials: JS
authors.lastname: Kim
authors.forename: Hae-Wook
authors.initials: HW
authors.lastname: Yoo
authors.forename: Hyung Ouk
authors.initials: HO
authors.lastname: Choi
authors.forename: Hee-Tae
authors.initials: HT
authors.lastname: Jung
keywords: Chemiresistor; MoS2; VOC; gas sensor; molybdenum disulfides; volatile organic compound