{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/30480"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/30480","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Long-Period Gratings as Immuno-Diagnostic biosensors","abstract":"This research presents a novel biosensor which utilizes the refractive index sensitivity of a fiber optic long-period grating. The long period grating couples light from the forward propagating guided core mode of a single-mode fiber into discrete circularly symmetric cladding modes. Due to imperfections in the cladding surface, loss bands are seen in the transmission spectrum corresponding to the coupled wavelengths. Based on the phase-matching condition between the coupling and coupled modes, the loss bands shift with changes in the refractive index of the surrounding medium. The grating surface is chemically treated to covalently bond antibody to the cladding of the sensor. Treatment with the proper antigen increases the effective index seen by the cladding modes and affects the placement of the loss bands. This sensor demonstrates specific antigen binding capacity with loss band shifts of 10 nm or more. The device offers several advantages over the widely used Enzyme-Linked Immuno-Sorbent Assays. Diagnostic applications can be expanded beyond the tests presented here.","abstract_html":"This research presents a novel biosensor which utilizes the refractive index sensitivity of a fiber optic long-period grating. The long period grating couples light from the forward propagating guided core mode of a single-mode fiber into discrete circularly symmetric cladding modes. Due to imperfections in the cladding surface, loss bands are seen in the transmission spectrum corresponding to the coupled wavelengths. Based on the phase-matching condition between the coupling and coupled modes, the loss bands shift with changes in the refractive index of the surrounding medium. The grating surface is chemically treated to covalently bond antibody to the cladding of the sensor. Treatment with the proper antigen increases the effective index seen by the cladding modes and affects the placement of the loss bands. This sensor demonstrates specific antigen binding capacity with loss band shifts of 10 nm or more. The device offers several advantages over the widely used Enzyme-Linked Immuno-Sorbent Assays. Diagnostic applications can be expanded beyond the tests presented here.","abstract_has_math":false,"creators":["D'Alberto, Tiffanie Gabrielle"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical and Computer Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Murphy, Kent A."],"committee_members":["Besieris, Ioannis M.","Claus, Richard O."],"year":1997,"date_issued":"1997-01-27","date_published":"1997-01-27","updated_at":"2026-07-22T22:19:04Z","subjects":["Biosensor","Fiber Optics","Evanescent Field","Diffraction Gratings","Immunoassay"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-345617310975300"],"render_values":[{"text":"etd-345617310975300","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/30480","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Murphy, Kent A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Besieris, Ioannis M.","Claus, Richard O."]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["D'Alberto, Tiffanie Gabrielle"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:21:50Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:21:50Z","1998-01-27"]},{"key":"dc:date.issued","label":"Date","values":["1997-01-27"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biosensor","Fiber Optics","Evanescent Field","Diffraction Gratings","Immunoassay"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-345617310975300"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/30480"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This research presents a novel biosensor which utilizes the refractive index sensitivity of a fiber optic long-period grating. The long period grating couples light from the forward propagating guided core mode of a single-mode fiber into discrete circularly symmetric cladding modes. Due to imperfections in the cladding surface, loss bands are seen in the transmission spectrum corresponding to the coupled wavelengths. Based on the phase-matching condition between the coupling and coupled modes, the loss bands shift with changes in the refractive index of the surrounding medium. The grating surface is chemically treated to covalently bond antibody to the cladding of the sensor. Treatment with the proper antigen increases the effective index seen by the cladding modes and affects the placement of the loss bands. This sensor demonstrates specific antigen binding capacity with loss band shifts of 10 nm or more. The device offers several advantages over the widely used Enzyme-Linked Immuno-Sorbent Assays. Diagnostic applications can be expanded beyond the tests presented here."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Long-Period Gratings as Immuno-Diagnostic biosensors"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Murphy, Kent A."],"dc:contributor.committeemember":["Besieris, Ioannis M.","Claus, Richard O."],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["D'Alberto, Tiffanie Gabrielle"],"dc:date.accessioned":["2014-03-14T20:21:50Z"],"dc:date.available":["2014-03-14T20:21:50Z","1998-01-27"],"dc:date.issued":["1997-01-27"],"dc:description.abstract":["This research presents a novel biosensor which utilizes the refractive index sensitivity of a fiber optic long-period grating. The long period grating couples light from the forward propagating guided core mode of a single-mode fiber into discrete circularly symmetric cladding modes. Due to imperfections in the cladding surface, loss bands are seen in the transmission spectrum corresponding to the coupled wavelengths. Based on the phase-matching condition between the coupling and coupled modes, the loss bands shift with changes in the refractive index of the surrounding medium. The grating surface is chemically treated to covalently bond antibody to the cladding of the sensor. Treatment with the proper antigen increases the effective index seen by the cladding modes and affects the placement of the loss bands. This sensor demonstrates specific antigen binding capacity with loss band shifts of 10 nm or more. The device offers several advantages over the widely used Enzyme-Linked Immuno-Sorbent Assays. Diagnostic applications can be expanded beyond the tests presented here."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-345617310975300"],"dc:identifier.uri":["http://hdl.handle.net/10919/30480"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Biosensor","Fiber Optics","Evanescent Field","Diffraction Gratings","Immunoassay"],"dc:title":["Long-Period Gratings as Immuno-Diagnostic biosensors"],"dc:type":["Thesis"],"thesis:degree_discipline":["Electrical and Computer Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:04Z"}