In Flow Enhanced Fluorescent Multi-coloured Silica Nanophotonics based on Bio-FRET of Cyanobacteria

CARINA SALINAS; F. BRACQUEMONT; DENIS BOUDREAU; ALICIA V. VEGLIA; VALERIA AME; A. GUILLERMO BRACAMONTE

Cordoba

Congreso; II Brazil-Argentine Microfluidics Congress/ V Congreso de Microfluídica Argentina; 2019

FAMAF, UNC

Fluorescent Silica Nanoparticles (SiO2 NPs) were synthesized based on the classical Störber method for Cyanobacteria labelling. Modified mono-coloured SiO2 NPs with Fluorescein (Fl) and Rhodamine B (RhB) were obtained (SiO2-Fl and SiO2-RhB NPs); and Multi-coloured SiO2 NPs with the incorporation of both emitters (SiO2-RhB-Fl NPs)were tuned for optimal emissions and Biodetection of Cyanobacteria (Cysbact.) by Laser Fluorescence Microscopy and In Flow Cytometry with Laser excitation and Fluorescence detection. By TEM Homogeneous SiO2 NPs of 180.0 nm diameters were recorded. These sizes were slightly increased due to the covalent linking incorporation of the Fluorescent dye emitters to 210.0 nm sizes with and amined-organosilane. These Fluorescent SiO2 NPs showed variable emission depending of the dye emitter concentrations, quantum yields and applied Luminescent pathways. Mono-coloured SiO2-Fl and SiO2-RhB NPs showed diminished emissions in comparison to Multi-coloured SiO2-RhB-Fl NPs. This enhancement was explained by Fluorescence Resonance Energy Transfer (FRET) between Fl as Fluorescent Energy Donor, and RhB as Energy acceptor produced within the Nanoarchitecture, produced just only in presence of both fluorophores with excitation of the Energy donor.The depositions of the Nano-emitters over Cyanobacteria by non-covalent interactions were observed by TEM and Laser Fluorescence Microscopy. For Multi-coloured SiO2-RhB-Fl NPs labelling it was observed Bio-FRET between the emission of the Nano-labellers and the natural fluorophores from the Cyanobacteria that produced diminished emission in comparison to Mono-coloured SiO2-Fl labelling. In this manner for Enhanced Luminescent Nanoplatforms tracking, the Multi-coloured SiO2-RhB-Fl NPs showed improved properties; while higher Luminescent Bio-surfaces were obtained with Mono-coloured SiO2-Fl labelling that permitted faster Cyanobacteria detection and counting by Laser Fluorescence Microscopy and In Flow Cytometry with Laser excitation.