Unusual energy transfer from photosynthetic antennae to graphene

Marcin Szalkowskia, Alessandro Surrenteb, Dorota Kowalskaa, Izabela Kamińskaa, Paulina Płochocka-Maudeb, Sebastian Maćkowskia
aInstitute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland; bLaboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France

In last decade graphene and its derivatives have been the subject of intensive studies. Some of the research concerns exploiting the acceptor properties of graphene, as its absorption is constant and spans over the whole visible range [1]. Moreover, high electrical conductivity and broad possibilities of surface functionalization render graphene as an attractive material for electrodes in solar cell architectures.

We present optical studies of a hybrid system consisting of a graphene layer and photosynthetic complexes – antennae Peridinin-Chlorophyll-Protein complexes (PCP) from the algae Amphidinium carterae. This water-soluble complex has well-known structure and energetic relations between its components, therefore it is widely used as a model system for examination of nanoscale interactions.

We focus on the energy transfer from PCP to graphene. Fluorescence steady-state and time-resolved microscopy studies, have shown strong quenching of the fluorescence intensity of photosynthetic complexes when deposited on graphene. Surprisingly we found that fluorescence quenching in such hybrid system is nonlinear – despite the uniform absorption of graphene - and efficiency of this process strongly depends on the excitation wavelength [2]. Detailed studies, where fluorescence excitation spectra were measured, reveal that the efficiency of the energy transfer is significantly enhanced in the blue spectral region, whereas it is highly suppressed for longer wavelengths. This is the first demonstration of such an effect in energy transfer assemblies.

Acknowledgement

Research was supported by the projects DEC-2013/11/B/ST3/03984 and DEC-2013/10/E/ST3/00034 funded by the National Science Center.

References

[1] K. Wiwatowski, A. Dużyńska, M. Świniarski, M. Szalkowski, M. Zdrojek, J. Judek, S. Mackowski and I. Kaminska, Journal of. Luminescence 2016, 170, 855–859.
[2] S. Mackowski and I. Kamińska, Applied Physics Lettters 2015, 107(2), 023110.