title: Local probe oxidation of self-assembled monolayers on hydrogen-terminated silicon.
abstract: Local probe oxidation experiments by conductive AFM have been performed on a hexadecyl monolayer and a N-hydroxysuccinimide (NHS)-ester-functionalized undecyl (NHS-UA) monolayer assembled on hydrogen-terminated (i.e., unoxidized) silicon. The oxidation conditions for the mild oxidation of the top terminal groups of monolayers and the deep oxidation of the underlying silicon into silicon oxide were investigated. The results show that the bias threshold for the AFM tip-induced oxidation of the top groups of monolayers on oxide-free silicon can be reduced by 2 V for the methyl-terminated hexadecyl monolayer and even by 3.5 V for the active NHS-ester-terminated undecyl monolayer, in comparison to a methyl-terminated octadecyl trichlorosilane (OTS) monolayer on oxidized silicon. Upon such local mild oxidation, the active NHS ester group of the NHS-UA monolayer is selectively cleaved off to generate carboxyl-containing monolayer nanopatterns, opening further possibilities for subsequent patterned multifunctionalization.
authors.affiliation: Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
authors.forename: Menglong
authors.initials: M
authors.lastname: Yang
authors.forename: Daan
authors.initials: D
authors.lastname: Wouters
authors.forename: Marcel
authors.initials: M
authors.lastname: Giesbers
authors.forename: Ulrich S
authors.initials: US
authors.lastname: Schubert
authors.forename: Han
authors.initials: H
authors.lastname: Zuilhof
mesh_terms: D000588:Amines / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D012825:Silicon / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013388:Succinimides / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000588:Amines; D002264:Carboxylic Acids; D013388:Succinimides; D013438:Sulfhydryl Compounds; D002244:Carbon; D012822:Silicon Dioxide; D006859:Hydrogen; C001426:N-hydroxysuccinimide; D012825:Silicon