title: Microlandscaping of Au nanoparticles on few-layer MoS2 films for chemical sensing.
abstract: Surface modification or decoration of ultrathin MoS2 films with chemical moieties is appealing since nanointerfacing can functionalize MoS2 films with bonus potentials. In this work, a facile and effective method for microlandscaping of Au nanoparticles (NPs) on few-layer MoS2 films is developed. This approach first employs a focused laser beam to premodify the MoS2 films to achieve active surface domains with unbound sulfur. When the activated surface is subsequently immersed in AuCl3 solution, Au NPs are found to preferentially decorate onto the modified regions. As a result, Au NPs can be selectively and locally anchored onto designated regions on the MoS2 surface. With a scanning laser beam, microlandscapes comprising of Au NPs decorated on laser-defined micropatterns are constructed. By varying the laser power, reaction time and thickness of the MoS2 films, the size and density of the NPs can be controlled. The resulting hybrid materials are demonstrated as efficient Raman active surfaces for the detection of aromatic molecules with high sensitivity.
authors.affiliation: Department of Physics, 2 Science Drive 3, National University of Singapore, 117542, Singapore.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Lu
authors.forename: Jia Hui
authors.initials: JH
authors.lastname: Lu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Lili
authors.initials: L
authors.lastname: Gong
authors.forename: Eng Soon
authors.initials: ES
authors.lastname: Tok
authors.forename: Kian Ping
authors.initials: KP
authors.lastname: Loh
authors.forename: Chorng Haur
authors.initials: CH
authors.lastname: Sow
mesh_terms: D000327:Adsorption; D004220:Disulfides / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000032:analysis* / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008982:Molybdenum / Q000737:chemistry*; D010316:Particle Size; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D004220:Disulfides; D006841:Hydrocarbons, Aromatic; D006046:Gold; D008982:Molybdenum; C082964:molybdenum disulfide
keywords: 2D materials; Au nanoparticles; molecule detection; surface-enhanced Raman; transition metal dichalcogenides