Site-Selective Chelation and Excitation Energy Transfer between the Higher Plant Major Light-Harvesting Complexes and Quantum Dots

Abstract

The major light-harvesting complexes of photosystem II(LHCII) have been linked to many organic or inorganic materials to construct bio-inspired new hybrid materials. In this study, the authors reported a hybrid complex of recombinant LHCII and water-soluble quantum dots(QD) linked by nickel-nitriloacetic acid(NTA·Ni) with a series of molar ratio between LHCII and QD(1∶64, 1∶32, 1∶16, 1∶12, 1∶8, 1∶4,1∶2.7, 1∶2, 1∶1.6) on the QD and histidine tag on the LHCII. The spectroscopic results showed that the fluorescence at 680 nm from LHCII increased when more QD molecules were put into the hybrid system.The enhancement reached the maximum and saturated when the molar ratio between LHCII and QD was2.7∶1. The fluorescence spectra results could be explained by resonance energy transfer mechanism from QD to LHCII. Moreover, no obvious energy transfer was observed between native LHCII and QD mixture and this highlighted the necessity of linkage for such energy transfer.