Análisis espectral de nanopartículas plasmónicas usando microscopía de campo obscuro

In this work, we present a dark field microscope for the study of gold nanoparticles (NPs). This microscopy method is based on a configuration of total internal reflection (TIR) that allows to obtain images of NPs excited by an evanescent field. Our system is based on an objetive of a large numerica...

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Detalles Bibliográficos
Autor: Gabriel Villatoro
Tipo de recurso: tesis de maestría
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:México
Institución:Instituto Nacional de Astrofísica, Óptica y Electrónica
Repositorio:Repositorio Institucional del INAOE
Idioma:español
OAI Identifier:oai:inaoe.repositorioinstitucional.mx:1009/2011
Acceso en línea:http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/2011
Access Level:acceso abierto
Palabra clave:info:eu-repo/classification/Inspec/Nanobiophotonics
info:eu-repo/classification/Inspec/Single-molecule
info:eu-repo/classification/Inspec/Plasmonic nanoparticles
info:eu-repo/classification/Inspec/Dark field microscopy
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/22
info:eu-repo/classification/cti/2209
info:eu-repo/classification/cti/220990
Descripción
Sumario:In this work, we present a dark field microscope for the study of gold nanoparticles (NPs). This microscopy method is based on a configuration of total internal reflection (TIR) that allows to obtain images of NPs excited by an evanescent field. Our system is based on an objetive of a large numerical aperture (NA), which collects light and sends it to a CMOS detector used as an eyepiece. We developed a light collection system, which allows scattered light to be collected by the gold NPs through a multimode optical fiber coupled to the dark field microscope. This light is finally transmitted and analyzed by a spectrometer. Two samples of gold nanoparticles were analyzed. A sample in solution, chemically synthesized by the Turkevich method and a sample made by a lithographic method which has gold nanostructures printed on glass. A lighting system based on total internal reflection was implemented, which uses two light emitting diodes (LED) and a slide used as a waveguide, an economical, novel and less difficult to use system. The results show that our dark field microscope is a method that distinguishes gold nanoparticles with diameters of 26 nm and 39 nm. It was also possible to simultaneously measure the spectrum scattered by said gold nanoparticles and the changes in their surrounding environment.