Violet ZnSe/ZnS as an Alternative to Green CdSe/ZnS in Nanocrystal−Fluorescent Protein FRET Systems

VITOR R. HERING; TANIZE E. S. FAULIN; EDUARDO R. TRIBONI; SILVIO D. RODRIGUEZ; DELIA L. BERNIK; ROBERT I. SCHUMACHER; VICTOR P. MAMMANA; ADELAIDE FALJONI-ALARIO; DULCINEIA S. P. ABDALLA; GARY GIBSON; MÁRIO J. POLITI

Bioconjugate Chemistry

ACS Publications

Año: 2009 vol. 20 p. 1237 - 1241

1043-1802

Fluorescent proteins from the green fluorescent protein family strongly interact with CdSe/ZnS and ZnSe/ZnS nanocrystals at neutral pH. Green emitting CdSe/ZnS nanocrystals and red emitting fluorescent protein dTomato constitute a 72% efficiency FRET system with the largest alteration of the overall photoluminescence profile, following complex formation, observed so far. The substitution of ZnSe/ZnS for CdSe/ZnS nanocrystals as energy donors enabled the use of a green fluorescent protein, GFP5, as energy acceptor. Violet emitting ZnSe/ZnS nanocrystals and green GFP5 constitute a system with 43% FRET efficiency and an unusually strong sensitized emission. ZnSe/ZnS-GFP5 provides a cadmium-free, high-contrast FRET system that covers only the high-energy part of the visible spectrum, leaving room for simultaneous use of the yellow and red color channels. Anisotropic fluorescence measurements confirmed the depolarization of GFP5 sensitized emission.