Layer-by-layer immobilization of carbon dots fluorescent nanomaterials on single optical fiber

• Autor(a) principal: Gonçalves, Helena M. R.
• Data de Publicação: 2012
• Outros Autores: Duarte, Abel J., Davis, Frank, Higson, Seamus P. J., Silva, Joaquim C. G. Esteves da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/2036
• topic: Carbon dots; Nanoparticles; Layer-by-layer immobilization; Single optical fiber; Mercury sensor

We report within this paper the development of a fiber-optic based sensor for Hg(II) ions. Fluorescent carbon nanoparticles were synthesized by laser ablation and functionalized with PEG200 and N-acetyl-l-cysteine so they can be anionic in nature. This characteristic facilitated their deposition by the layer-by-layer assembly method into thin alternating films along with a cationic polyelectrolyte, poly(ethyleneimine). Such films could be immobilized onto the tip of a glass optical fiber, allowing the construction of an optical fluorescence sensor. When immobilized on the fiber-optic tip, the resultant sensor was capable of selectively detecting sub-micromolar concentrations of Hg(II) with an increased sensitivity compared to carbon dot solutions. The fluorescence of the carbon dots was quenched by up to 44% by Hg(II) ions and interference from other metal ions was minimal.