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Cover Picture: High‐Resolution Surface Chemical Analysis of a Trifunctional Pattern Made by Sequential Colloidal Shadowing (ChemPhysChem 17/2010)
Author(s) -
Ogaki Ryosuke,
Lyckegaard Folmer,
Kingshott Peter
Publication year - 2010
Publication title -
chemphyschem
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201090084
Subject(s) - monolayer , colloid , chemistry , layer (electronics) , resolution (logic) , substrate (aquarium) , nanotechnology , analytical chemistry (journal) , materials science , organic chemistry , oceanography , artificial intelligence , geology , computer science
The cover picture represents how three chemistries can be readily patterned on a surface by using a combination of colloidal lithography, physical vapour deposition and self‐assembled monolayers, as described on p. 3609 by Kingshott et al. Inspired by a layer‐cake concept, a sequential masking can be performed by overlaying a hexagonally close‐packed monolayer of colloids on top of each other, where the second layer of colloids periodically masks the alternating interstitial spaces of the first layer. The gold layer (shown in yellow) is first deposited through the interstitial spaces of a first monolayer of colloids and the first set of thiols (biotinylated thiols, red) is immobilized. Another monolayer of HCP colloids is deposited on top and the subsequent deposition of gold is performed in the interstitial spaces, periodically burying the first set of thiols and creating a fresh gold surface for the immobilization of the second set of thiols (fluorinated thiols, green). The double layer of colloids is finally removed, revealing a periodical pattern of the two different thiols and the bare substrate (SiO 2 , blue). The pattern is confirmed by using time‐of‐flight secondary ion mass spectrometry, yielding a secondary ion image with sub‐micron lateral resolution (right‐hand image). The top left‐hand corner represents the X‐ray photoelectron spectra of the C 1s high‐resolution scan, revealing that no replacement is taking place between the two set of thiols.