Biosensing for disease monitoring: metallic nanohole array plasmonic sensors based on scalable nanofabrication techniques
- Autores: Deitze Otaduy del Paso
- Directores de la Tesis: Fernando Moreno Gracia (dir. tes.), Santos Merino Álvarez (codir. tes.)
- Lectura: En la Universidad de Cantabria ( España ) en 2019
- Idioma: inglés
- Títulos paralelos:
- Biosensado para la monitorización de enfermedades: sensores plasmónicos con redes de nanoagujeros metálicos basados en técnicas de nanofabricación escalables
- Tribunal Calificador de la Tesis: Manuel Nieto Vesperinas (presid.), José María Saiz Vega (secret.), Christophe Vieu (voc.)
- Programa de doctorado: Programa de Doctorado en Ciencia y Tecnología por la Universidad de Cantabria
- Materias:
- Enlaces
- Tesis en acceso abierto en: UCrea
- Resumen
- español
En esta tesis se ha modelizado y desarrollado un biosensor compatible con una producción a nivel industrial, basado en tecnología plasmónica y formado por chips compuestos de matrices de nanoagujeros en películas delgadas de oro. El biosensor propuesto permite no sólo cuantificar la concentración de proteínas en una muestra biológica, sino también la identificación y el contaje de células. Se presenta, por tanto, como alternativa de diagnóstico y/o seguimiento de pacientes con enfermedades de alto impacto social y económico, como el cáncer, enfermedades inflamatorias autoinmunes u otras patologías cuyos biomarcadores sean bien conocidos. Esta investigación, apoyada por el diseño y fabricación de una microfluídica y un sistema óptico de inspección ad-hoc, ha permitido validar el biosensor propuesto para la monitorización de ciertas enfermedades. El trabajo, extensible a otros biomarcadores de interés, puede suponer un avance en el desarrollo de sistemas de diagnóstico point-of-care en el campo creciente de las biopsias líquidas.
- English
The main goal of this doctoral thesis is the development of scalable biosensors based on plasmonic technology as alternative solutions for its implementation in diagnosis or therapy monitoring of relevant diseases, such as cancer, autoimmune inflammatory diseases or any other pathology with well-known biomarkers. The use of nanoplasmonic biosensors for a rapid, sensitive and label-free detection of biomarkers present in human fluids, such as tumor cells or proteins, is proposed. The biosensor consists of sensing chips made of periodic nanoholes arrays on a gold surface where the extraordinary optical transmission is present when light interacts with the nanostructured metal surface.
The nanostructured geometry to be fabricated in the metal film (sensing chip) for high sensitivity in biosensing, was analyzed by computational simulations in order to get optimal performance. This geometry had to be compatible with the scalable and low-cost manufacturing method used in this research: thermal Nanoimprint Lithography (NIL). Also, for micron-sized biological objects like cells, the electromagnetic behavior of the sensing chip when one of these dielectric objects is located on it, was numerically studied. This numerical simulation allowed to determine the capacity of the biosensor for detection and monitoring of single cells in buffer solution. It also set the optical setup requirements to reach this goal.
An in-depth study of the thermal NIL process was carried out for a better control and an optimization of the sensing chip fabrication process. Next, the experimental procedure for chip fabrication and chip characterization were optimized to get a robust manufacturing process.
A novel and suitable optical setup was developed to carry out the experimental measurements of the system as biosensor, especially for the detection, monitoring and counting of tumor cells. In addition, this optical configuration allows an automatic sensing chips characterization, quality control, by a fast scanning of the chips and a further data processing. The possibility of characterizing nanofeatures in a simple way together with the industrial scalable fabrication technology selected would bridge the gap between lab and industry for nanoplasmonic sensors.
Last, experimental measurements data are presented and discussed, showing the biosensing capabilities of the designed system, accordingly with the numerical calculations previously done. Biomarkers detection were performed in fluid samples. Three cases of study showing the potential of the developed plasmonic biosensor are presented in this work: the real-time monitoring of BSA protein adsorption, the detection of the protein TNF-α by means of a label-free immunoassay and the detection of micro-sized objects such as HT-29 cells, a human colon cancer cell line.
This thesis work has been developed in an interdisciplinary group in close collaboration with other researchers from the Universidad de Cantabria, Hospital Universitario Marqués de Valdecilla, and a SME, CELLBIOCAN.
This work paves the way for the further construction of a biosensor prototype as a lab-on-chip sensor. It could represent an important benefit for the medicine based on liquid biopsies, for instance, for an early detection of possible cancer metastasis and monitoring patients during treatment or after treatment. The work in this thesis could also contribute to the clinical monitoring of patients suffering from an inflammatory process such as autoimmune inflammatory diseases or cancer and particularly, to the follow-up of patients taking biological drugs acting as TNF-α activity blockers. This work contributes to smooth the path towards medical attention based on personalized medicine, which reduce significantly the cost by avoiding non-effective therapies while the prognosis and treatment of a certain ailment is largely improved.
- español
