Enhancing the Light Coverage of Photosynthetic Bacteria to Augment Photosynthesis by Conjugated Polymer Nanoparticles

By coating photosynthetic bacteria of Rhodopseudomonas palustris with conjugated polymers nanoparticles modified with positively charged peptide TAT (CPNs-TAT), a bio-optical hybrid composite of R. palustris/CPNs-TAT has been constructed. R. palustris/CPNs-TAT augments the light coverage of R. palustris to broaden the R. palustris absorption due to excellent light-harvesting properties of CPNs-TAT, especially in the ultraviolet region. It leads to converting ultraviolet light to visible light that could be absorbed by R. palustris, allowing antenna systems around the reaction center (RC) of the photosynthetic membrane to absorb more photons, thus photons are excited and transferred to the RC where the electron-hole separation occurs. Therefore, R. palustris/CPNs-TAT improves adenosine triphosphate (ATP) synthesis by increasing proton gradient, resulting in the enhancement of the photosynthetic activity. This effort combines synthetic light-harvesting materials with photosynthetic bacteria without complicated genetic techniques to obtain the hybrid bio-optical systems for augmenting photosynthesis beyond natural photosynthetic bacteria.