Glass Microfluidic platforms for molecular detection by SERS

• Autor(a) principal: Ferreira, Bernardo Matos Alves Costa
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/19922
• topic: Microfluidics; Surface enhanced Raman spectroscopy (SERS); Zinc oxide (ZnO); Nanorods; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

Nowadays due to increasing concerns in public health, technologies have been developed for the sensitive detection of food contaminants. Since current methods are time-consum-ing, expensive and complex to operate, this project has as the objective to develop a mi-crofluidics device for surface enhanced Raman spectroscopy (SERS). SERS consists in a simple, robust, sensitive and fast technique for detection of ves-tigial components that can be advantageously adapted to the detection of food contami-nants. In order to develop an appropriate substrate for SERS, a study was performed of different parameters for the hydrothermal synthesis of zinc oxide nanorods (temperature, time and pH). Afterwards, they were covered with silver nanoparticles with different thicknesses (2, 4, 6 e 8 nm) deposited by physical vapour deposition (PVD), originating the substrate Ag NPs@ZnONRs. The efficiency of the different substrates was similar, regardless the thickness of silver, with enhancement factor (EF) values around 105~106. Simultaneously, obelisk nanorods were developed with good SERS efficiency, and EFs around 106. Finally, it was created a microfluidics device in PDMS, which allowed to observe the SERS signal of a rhodamine-6G solution in its interior. The assays performed in the work allowed to infer the behaviour of SERS signal with different geometric parameters of components of SERS substrates.