Layer-by-layer immobilization of carbon dots fluorescent nanomaterials on single optical fiber.
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 PEG(200) 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.
Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal.
Helena M R
HM
Gonçalves
Abel J
AJ
Duarte
Frank
F
Davis
Seamus P J
SP
Higson
Joaquim C G
JC
Esteves da Silva
D000111:Acetylcysteine / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002413:Cations, Divalent / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D055100:Optical Fibers; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods
D002413:Cations, Divalent; D005456:Fluorescent Dyes; D002244:Carbon; D008628:Mercury; D000111:Acetylcysteine