title: Evaluation of Chemical Interactions between Small Molecules in the Gas Phase Using Chemical Force Microscopy.
abstract: Chemical force microscopy analyzes the interactions between various chemical/biochemical moieties in situ. In this work we examined force-distance curves and lateral force to measure the interaction between modified AFM tips and differently functionalized molecular monolayers. Especially for the measurements in gas phase, we investigated the effect of humidity on the analysis of force-distance curves and the images in lateral force mode. Flat chemical patterns composed of different functional groups were made through micro-contact printing and lateral force mode provided more resolved analysis of the chemical patterns. From the images of 1-octadecanethiol/11-mercapto-1-undecanoic acid patterns, the amine group functionalized tip brought out higher contrast of the patterns than an intact silicon nitride tip owing to the additional chemical interaction between carboxyl and amine groups. For more complex chemical interactions, relative chemical affinities toward specific peptides were assessed on the pattern of 1-octadecanethiol/phenyl-terminated alkanethiol. The lateral image of chemical force microscopy reflected specific preference of a peptide to phenyl group as well as the hydrophobic interaction.
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea. simsj@korea.ac.kr.|Department of Chemical and Biological Engineering, Korea University, 5-ga Annam-dong, Seongbuk-gu, Seoul 136-713, Korea. simsj@korea.ac.kr.
authors.forename: Jieun
authors.initials: J
authors.lastname: Lee
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea. ssumi0115@gmail.com.
authors.forename: Soomi
authors.initials: S
authors.lastname: Ju
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea. fresh1606@naver.com.
authors.forename: In Tae
authors.initials: IT
authors.lastname: Kim
authors.affiliation: Center for Neuro-Medicine, Brain Science Institute, Korea Institute of Science and Technology(KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea. shjung8748@gmail.com.
authors.forename: Sun-Hwa
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Department of Applied Chemistry, Hanyang University, Sangnok-gu, Ansan, Gyeonggi-do 15588, Korea. sjmin@hanyang.ac.kr.
authors.forename: Sun-Joon
authors.initials: SJ
authors.lastname: Min
authors.affiliation: Center for Sensor System Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea. chulki.kim@kist.re.kr.
authors.forename: Chulki
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, 5-ga Annam-dong, Seongbuk-gu, Seoul 136-713, Korea. simsj@korea.ac.kr.
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Sim
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea. sangk@kist.re.kr.
authors.forename: Sang Kyung
authors.initials: SK
authors.lastname: Kim
mesh_terms: D001554:Benzene / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D005740:Gases / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D010455:Peptides / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: C505222:11-mercaptoundecanoic acid; D005227:Fatty Acids; D005740:Gases; D010455:Peptides; D013438:Sulfhydryl Compounds; C055360:n-octadecyl mercaptan; D001554:Benzene
keywords: benzene  specific peptide; chemical force microscopy; lateral force image; micro-contact printing