Novel multilayer core-shell nanoprobes based on Metal-Enhanced FRET for biosensing applications

MAXIME RIOUX, A.-GUILLERMO BRACAMONTE, MATHIEU L.-VIGER, AND DENIS BOUDREAU

Toronto

Congreso; CSC, Canadien society for chemistry 2009; 2009

Our research group is working on the development of multilayer core-shell nanoparticles (NPs) featuring a metal core surrounded by concentric silica layers containing fluorophores positioned at precise distances from the core. Recent results show that the controlled geometry of these core-shell NPs enhances fluorescence intensity and photostability several-fold through plasmonic coupling with the core and improves Förster Resonant Energy Transfer (FRET) efficiency and range between donoracceptor pairs.1 These enviable characteristics make such multilayer core-shell NPs a promising alternative to improve detection sensitivity, photostability as well as FRET range and efficiency in a variety of applications. In this poster presentation, we will describe the progress accomplished in three projects related to the tailoring of multilayer luminescent NPs for biosensing applications: i) The identification of blood genotypes using bioconjugated fluorescent silica-coated silver nanoparticles grafted with probe oligonucleotides and complexed with an optical polymeric hybridization transducer. The capture of human genomic DNA onto the surface of the NP allows the excitation light to be coupled to the FRET acceptor immobilized in the silica shell, resulting in enhanced detection sensitivity; ii) The detection of intracellular Ca2+ using a nanosensor based on the Fluo-4 Ca2+-specific indicator grafted onto small fluorescent silica-coated gold nanoparticles. Excitation of the calcium-complexed Fluo-4 molecules leads to metal-enhanced FRET to the acceptors immobilized in the silica shell; and iii) Application of the above scheme to the development of optically-traceable drug delivery nanocarriers, where the amplitude of Metal-Enhanced FRET is modulated by the release of fluorescent molecules hosted by cyclodextrin-grafted nanoparticles.and improves Förster Resonant Energy Transfer (FRET) efficiency and range between donoracceptor pairs.1 These enviable characteristics make such multilayer core-shell NPs a promising alternative to improve detection sensitivity, photostability as well as FRET range and efficiency in a variety of applications. In this poster presentation, we will describe the progress accomplished in three projects related to the tailoring of multilayer luminescent NPs for biosensing applications: i) The identification of blood genotypes using bioconjugated fluorescent silica-coated silver nanoparticles grafted with probe oligonucleotides and complexed with an optical polymeric hybridization transducer. The capture of human genomic DNA onto the surface of the NP allows the excitation light to be coupled to the FRET acceptor immobilized in the silica shell, resulting in enhanced detection sensitivity; ii) The detection of intracellular Ca2+ using a nanosensor based on the Fluo-4 Ca2+-specific indicator grafted onto small fluorescent silica-coated gold nanoparticles. Excitation of the calcium-complexed Fluo-4 molecules leads to metal-enhanced FRET to the acceptors immobilized in the silica shell; and iii) Application of the above scheme to the development of optically-traceable drug delivery nanocarriers, where the amplitude of Metal-Enhanced FRET is modulated by the release of fluorescent molecules hosted by cyclodextrin-grafted nanoparticles.