Tuning Silica Nanophotonics based on Fluorescence Resonance Energy Transfer (FRET) for targeted non-classical light delivery applications

CARINA SALINAS; MARTIN AME; A. GUILLERMO BRACAMONTE

JOURNAL OF NANOPHOTONICS

SPIE-SOC PHOTOPTICAL INSTRUMENTATION ENGINEERS

Año: 2020 vol. 14 p. 1 - 19

1934-2608

Tuneable Fluorescent Silica nanoparticles (SiO2 NPs) with variable size based on Fluorescence Resonance Energy Transfer (FRET) were synthesized. The SiO2 NPs were obtained by the Störber method by varying Tetraethyl orthosilicate (TEOS) concentrations and with the incorporation of different concentration levels of Fluorescein (Fl) and Rhodamine B (RhB) conjugated with 3-(aminopropyl)triethoxysilane, (APS), as well. We thus recorded homogeneous SiO2 NPs of different sizes. By TEM imaging, sizes of 200.0, 280.0 and 380.0 nm were determined. The Fl and RhB fluorescent dyes showed well overlapped emission from the Fluorescent Energy Donor to the Energy Acceptor, also accompanied with optimal ratio of quantum yields. By static Fluorescence varied emissions were recorded according to the concentration ratio of the donor-acceptor pair. Increasing intensity values were collected with the addition of higher concentrations of the Fluorescent Energy Donor and decreased Fluorescent Lifetime Decays. By Laser Fluorescence Microscopy higher enhanced surfaces were produced in the presence of both emitters, as compared to those in the presence of mono-coloured SiO2 NPs with optimal excitation with the Fluorescent Energy Donor only. These NPs were well dispersed in polar solvents; however due to their polar surface and size, higher interactions produced dimeric nano-aggregates. In addition, in order to evaluate their applications, their depositions were evaluated over modified glass slide substrates for smart light-responsive materials, and over Cyanobacteria and Escherichia Coli for the development of nano-biostructures with varied optical activities.