Time‐Resolved Studies of Energy Transfer in Thin Films of Green and Red Fluorescent Proteins

Abstract

Biologically derived fluorescent proteins are attractive candidates for lasing and sensing due to their excellent optical properties, including their high quantum yield, spectral tunability, and robustness against concentration quenching. Here, a time-resolved study of the fluorescence dynamics of protein thin films is reported for the enhanced green fluorescent protein (EGFP), the redemitting tandem-dimer protein tdTomato, and blends of EGFP and tdTomato. The exciton dynamics are characterized by using spectrally and time-resolved measurements of fluorescence and a threefold reduction in lifetime is observed when going from solution to thin film, down to 1 and 0.6 ns for EGFP and tdTomato, respectively. This finding is attributed to a dipole-dipole nonradiative Förster resonant energy transfer (FRET) in solid state. The temporal characteristics of FRET in blended thin films are also studied and increased nonradiative transfer rates are found. Finally, efficient sensitization of a semiconductor surface with a protein thin film is reported. Such a configuration may have important implications for energy harvesting in hybrid organicinorganic solar cells and other hybrid optoelectronic devices.

Site-Specific Protein Photochemical Covalent Attachment to Carbon Nanotube Side Walls and Its Electronic Impact on Single Molecule Function

“…Residue specific attachment of GFP to SWCNTs side-walls. Autofluorescent proteins such as green fluorescent protein (GFP; Figure 1b) are of current interest in the nanosciences as they are finding uses outside classical cell biology in areas ranging from optically gated transistors (34), LEDs through stimulated emission (35,36) and as light capture and energy transfer devices (37), such as for use in solar cell systems. They have particular advantages over organic molecules, not least because of their eco-friendly nature but that the protein encases the chromophore protecting it from the external environment and allowing modulation of its electronic properties through engineered changes in coupled bond networks.…”

Dimension-Tunable Circularly Polarized Luminescent Nanoassemblies with Emerging Selective Chirality and Energy Transfer

“…A fast decay process with the time constant of 2.84 ps at 390 nm is observed; correspondingly, a fast generation process with the time constant of 3.34 ps at 497 nm is also founded. The short lifetime of donor GluCN is closely correlated with the rise time of CNA, further confirming efficient energy transfer from GluCN to CNA …”

Site-Specific Protein Covalent Attachment to Nanotubes and Its Electronic Impact on Single Molecule Function

“…Residue specific attachment of GFP to SWCNTs side-walls. Autofluorescent proteins such as green fluorescent protein (GFP; Figure 1b) are of particular current interest in the nanosciences as they are finding uses outside classical cell biology in areas ranging from optically gated transistors 32 , LEDs through stimulated emission 33,34 and as light capture and energy transfer devices 35 , such as for use in solar cell systems. They have particular advantages over organic molecules, not least because of their eco-friendly nature but that the protein encases the chromophore protecting it from the external environment and allowing modulation of its electronic properties through engineered changes in coupled bond networks.…”