{"id":{"repo_id":"sherbrooke","oai_identifier":"oai:usherbrooke.scholaris.ca:11143/3102"},"canonical_url":"https://search.dev.ndltd.org/etd/sherbrooke/oai:usherbrooke.scholaris.ca:11143/3102","repository":{"repo_id":"sherbrooke","name":"Université de Sherbrooke","base_url":"https://usherbrooke.scholaris.ca/server/oai/request"},"display":{"title":"The application of scanning tunneling microscopy (STM) and related techniques to the study of organic and biomolecular targets","abstract":"Scanning tunneling microscopy (STM) has been used to study: (a) Self-assembled monolayers and sub-monolayers of butanethiol adsorbed onto highly uniform Au/mica films, (b) DNA adsorbates on different substrates prepared by different deposition techniques. In addition, surface preparation techniques have been investigated. Two strongly oxidizing solutions (sulfochromic and piranha acids) have been studied for the elimination of residual organic adsorbates on the Au/mica substrate. Treatment of the Au/mica surface with piranha acid leads to extensive and uncontrolled etching of the surface, and severe disruption of the surface topography. Limited exposure of the Au/mica surfaces to sulfochromic acid leads to the formation of permanent etch pits of the surface that are exclusively one Au layer deep; extended exposure leads to progressive lateral etching of the surface, ultimately leading to the formation of 3.3-3.6 A high islands on the otherwise flat surface. STM images taken of fully-equilibrated butanethiol monolayer films show molecularly resolved features that are believed to correspond to the methyl terminations of the organic surface. Large domains of organized adsorbates and a variant of the previously reported $p\\times\\surd3$ superlattice structure is observed on these surfaces; using this nomenclature, the basic repeat unit of the structure reported herein corresponds to a $7\\times\\surd3$ superlattice. The study of sub-monolayer films shows the island-like formations of SAMs on the gold surface; each island has same molecular structure as observed in monolayer films. Natural plasmids of different lengths together with chemically modified oligonucleotide sequences are adsorbed onto graphite and Au/mica surfaces and studied using the STM. High resolution images were obtained with clearly resolved helical structures.","abstract_html":"Scanning tunneling microscopy (STM) has been used to study: (a) Self-assembled monolayers and sub-monolayers of butanethiol adsorbed onto highly uniform Au/mica films, (b) DNA adsorbates on different substrates prepared by different deposition techniques. In addition, surface preparation techniques have been investigated. Two strongly oxidizing solutions (sulfochromic and piranha acids) have been studied for the elimination of residual organic adsorbates on the Au/mica substrate. Treatment of the Au/mica surface with piranha acid leads to extensive and uncontrolled etching of the surface, and severe disruption of the surface topography. Limited exposure of the Au/mica surfaces to sulfochromic acid leads to the formation of permanent etch pits of the surface that are exclusively one Au layer deep; extended exposure leads to progressive lateral etching of the surface, ultimately leading to the formation of 3.3-3.6 A high islands on the otherwise flat surface. STM images taken of fully-equilibrated butanethiol monolayer films show molecularly resolved features that are believed to correspond to the methyl terminations of the organic surface. Large domains of organized adsorbates and a variant of the previously reported $p\\times\\surd3$ superlattice structure is observed on these surfaces; using this nomenclature, the basic repeat unit of the structure reported herein corresponds to a $7\\times\\surd3$ superlattice. The study of sub-monolayer films shows the island-like formations of SAMs on the gold surface; each island has same molecular structure as observed in monolayer films. Natural plasmids of different lengths together with chemically modified oligonucleotide sequences are adsorbed onto graphite and Au/mica surfaces and studied using the STM. High resolution images were obtained with clearly resolved helical structures.","abstract_has_math":true,"creators":["Kang, Jing"],"institution":"Université de Sherbrooke","degree_name":"M. Sc.","degree_level":"Maîtrise","degree_discipline":"Sciences des radiations et imagerie biomédicale","degree_department":null,"school":null,"contributors":[],"advisors":["Rowntree, Paul A."],"committee_chairs":[],"committee_members":[],"year":1996,"date_issued":"1996","date_published":"1996","updated_at":"2026-07-27T21:07:47Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/11143/3102","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Rowntree, Paul A."]},{"key":"dc:creator","label":"Author","values":["Kang, Jing"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-05-15T18:36:48Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-05-15T18:36:48Z"]},{"key":"dc:date.issued","label":"Date","values":["1996"]},{"key":"dc:publisher","label":"Institution","values":["Université de Sherbrooke"]},{"key":"dc:type","label":"Dc Type","values":["Mémoire de maîtrise"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Sciences des radiations et imagerie biomédicale"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Maîtrise"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M. 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Two strongly oxidizing solutions (sulfochromic and piranha acids) have been studied for the elimination of residual organic adsorbates on the Au/mica substrate. Treatment of the Au/mica surface with piranha acid leads to extensive and uncontrolled etching of the surface, and severe disruption of the surface topography. Limited exposure of the Au/mica surfaces to sulfochromic acid leads to the formation of permanent etch pits of the surface that are exclusively one Au layer deep; extended exposure leads to progressive lateral etching of the surface, ultimately leading to the formation of 3.3-3.6 A high islands on the otherwise flat surface. STM images taken of fully-equilibrated butanethiol monolayer films show molecularly resolved features that are believed to correspond to the methyl terminations of the organic surface. Large domains of organized adsorbates and a variant of the previously reported $p\\times\\surd3$ superlattice structure is observed on these surfaces; using this nomenclature, the basic repeat unit of the structure reported herein corresponds to a $7\\times\\surd3$ superlattice. The study of sub-monolayer films shows the island-like formations of SAMs on the gold surface; each island has same molecular structure as observed in monolayer films. Natural plasmids of different lengths together with chemically modified oligonucleotide sequences are adsorbed onto graphite and Au/mica surfaces and studied using the STM. High resolution images were obtained with clearly resolved helical structures.","Des méthodes de microscopie à effet tunnel (STM) ont été utilisées pour regarder (a) des monocouches et sous-monocouches auto-assemblées de butanethiol adsorbées sur des films hautement uniformes Au/mica, (b) des molécules d'ADN adsorbés sur différents substrats. De plus, des recherches comportant le traitement des surfaces avant déposition ont été effectuées. Deux solutions fortement oxydantes (acides sulfochromique et piranha) ont été l'objet d'études pour l'élimination des résidus organiques adsorbés sur les substrats d'or. Les traitements des surfaces d'or, à l'aide de l'acide piranha, conduisent à une destruction intense et incontrôlable de la surface provoquant ainsi de sévères perturbations topographiques. L'exposition des surface Au/mica à des solutions d'acide sulfochromique pour une courte durée induit sur la surface des piqurations permanentes atteignant une profondeur maximale d'une couche d'or. Une exposition prolongée de cet acide provoque plutôt une corrosion progressive de la surface jusqu'à la formation d'îlots de 3.3-3.6 A de hauteur sur une surface autrement plane. Cette piquration contrôlée par l'acide sulfochromique a été utilisée pour la préparation du substrat dans les expériences subséquentes. Les images STM obtenues pour des monocouches de butanethiol, qui ont atteint l'équilibre, montrent à résolution moléculaire des particularités que nous pensons attribuables aux méthyles terminaux de la surface organique. De grands domaines d'adsorbats organisés et une variante de la structure du super-réseau pxYJ reporté dans des études précédentes, sont observés sur ces surfaces. En utilisant cette nomenclature, la maille élémentaire de la structure reportée ici correspond à 7x -0. Les variations latérales en l'élévation des structures endommagées sont associées, sous toute réserve, aux liaisons thiolates sur différents sites (i.e. sites/cc et hep) du substrat de Au(lll). Contrairement aux études par UHV-STM, il a été possible d'observer des structures moléculaires dans les régions du super-réseau. Ces observations suggèrent que le facteur de remplissage de surfaces qui ont atteint l'équilibre, est très sensible à la méthode de préparation et d'entreposage des échantillons."]},{"key":"dc:title","label":"Title","values":["The application of scanning tunneling microscopy (STM) and related techniques to the study of organic and biomolecular targets"]}]}],"canonical_facts":{"dc:contributor.advisor":["Rowntree, Paul A."],"dc:creator":["Kang, Jing"],"dc:date.accessioned":["2014-05-15T18:36:48Z"],"dc:date.available":["2014-05-15T18:36:48Z"],"dc:date.issued":["1996"],"dc:description.abstract":["Scanning tunneling microscopy (STM) has been used to study: (a) Self-assembled monolayers and sub-monolayers of butanethiol adsorbed onto highly uniform Au/mica films, (b) DNA adsorbates on different substrates prepared by different deposition techniques. In addition, surface preparation techniques have been investigated. Two strongly oxidizing solutions (sulfochromic and piranha acids) have been studied for the elimination of residual organic adsorbates on the Au/mica substrate. Treatment of the Au/mica surface with piranha acid leads to extensive and uncontrolled etching of the surface, and severe disruption of the surface topography. Limited exposure of the Au/mica surfaces to sulfochromic acid leads to the formation of permanent etch pits of the surface that are exclusively one Au layer deep; extended exposure leads to progressive lateral etching of the surface, ultimately leading to the formation of 3.3-3.6 A high islands on the otherwise flat surface. STM images taken of fully-equilibrated butanethiol monolayer films show molecularly resolved features that are believed to correspond to the methyl terminations of the organic surface. Large domains of organized adsorbates and a variant of the previously reported $p\\times\\surd3$ superlattice structure is observed on these surfaces; using this nomenclature, the basic repeat unit of the structure reported herein corresponds to a $7\\times\\surd3$ superlattice. The study of sub-monolayer films shows the island-like formations of SAMs on the gold surface; each island has same molecular structure as observed in monolayer films. Natural plasmids of different lengths together with chemically modified oligonucleotide sequences are adsorbed onto graphite and Au/mica surfaces and studied using the STM. High resolution images were obtained with clearly resolved helical structures.","Des méthodes de microscopie à effet tunnel (STM) ont été utilisées pour regarder (a) des monocouches et sous-monocouches auto-assemblées de butanethiol adsorbées sur des films hautement uniformes Au/mica, (b) des molécules d'ADN adsorbés sur différents substrats. De plus, des recherches comportant le traitement des surfaces avant déposition ont été effectuées. Deux solutions fortement oxydantes (acides sulfochromique et piranha) ont été l'objet d'études pour l'élimination des résidus organiques adsorbés sur les substrats d'or. Les traitements des surfaces d'or, à l'aide de l'acide piranha, conduisent à une destruction intense et incontrôlable de la surface provoquant ainsi de sévères perturbations topographiques. L'exposition des surface Au/mica à des solutions d'acide sulfochromique pour une courte durée induit sur la surface des piqurations permanentes atteignant une profondeur maximale d'une couche d'or. Une exposition prolongée de cet acide provoque plutôt une corrosion progressive de la surface jusqu'à la formation d'îlots de 3.3-3.6 A de hauteur sur une surface autrement plane. Cette piquration contrôlée par l'acide sulfochromique a été utilisée pour la préparation du substrat dans les expériences subséquentes. Les images STM obtenues pour des monocouches de butanethiol, qui ont atteint l'équilibre, montrent à résolution moléculaire des particularités que nous pensons attribuables aux méthyles terminaux de la surface organique. De grands domaines d'adsorbats organisés et une variante de la structure du super-réseau pxYJ reporté dans des études précédentes, sont observés sur ces surfaces. En utilisant cette nomenclature, la maille élémentaire de la structure reportée ici correspond à 7x -0. Les variations latérales en l'élévation des structures endommagées sont associées, sous toute réserve, aux liaisons thiolates sur différents sites (i.e. sites/cc et hep) du substrat de Au(lll). Contrairement aux études par UHV-STM, il a été possible d'observer des structures moléculaires dans les régions du super-réseau. Ces observations suggèrent que le facteur de remplissage de surfaces qui ont atteint l'équilibre, est très sensible à la méthode de préparation et d'entreposage des échantillons."],"dc:identifier.uri":["https://hdl.handle.net/11143/3102"],"dc:language.iso":["en"],"dc:publisher":["Université de Sherbrooke"],"dc:title":["The application of scanning tunneling microscopy (STM) and related techniques to the study of organic and biomolecular targets"],"dc:type":["Mémoire de maîtrise"],"thesis:degree_discipline":["Sciences des radiations et imagerie biomédicale"],"thesis:degree_level":["Maîtrise"],"thesis:degree_name":["M. Sc."],"thesis:institution_name":["Faculté de médecine et des sciences de la santé"]},"updated_at":"2026-07-27T21:07:47Z"}