Pan Xiaoqin, Li Dongna, Fang Yueping, Liang Zhihao, Zhang Haoran, Zhang Jin Zhong, Lei Bingfu, Song Shiwei
College of Horticulture, South China Agricultural University, Guangzhou 510642, P.R. China.
Guangdong Provincial Engineering Technology Research Center for Optical Agriculture, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, P.R. China.
J Phys Chem Lett. 2020 Mar 5;11(5):1822-1827. doi: 10.1021/acs.jpclett.9b03740. Epub 2020 Feb 20.
In this study, a hybrid semiartificial photosynthesis system based on chloroplast (CLP) and titanium oxide nanoparticles (TiO NPs) was constructed. 2,6-Dichlorophenolindophenol (DCPIP) reduction by TiO/CLP complex and methylene blue (MB) reduction by TiO were used to determine enhanced photogenerated electron transfer in this hybrid system. The DCPIP reduction by the TiO/CLP complex showed the same trend as MB reduction by TiO as a function of concentration of TiO NPs, indicating interception of photogenerated electrons in TiO by CLP that leads to enhanced photosynthesis efficiency. Decreased photoluminescence intensity and shortened excited-state lifetime of the TiO/CLP complex compared to that of pure TiO also support electron transfer from TiO to CLP. Longer visible light absorption wavelength and increasing valence band edges reveal the narrower band gap of TiO/CLP, which finally results in the enhanced electron transfer from TiO to CLP. Higher ferricyanide reduction and enhanced ATP formation with the TiO/CLP complex demonstrate the accelerated electron-transfer rate of the electron-transfer chain. This study reveals the mechanism of how TiO interacts with CLP to enhance the photosynthesis via constructing a semiartificial photosynthesis system.
在本研究中，构建了一种基于叶绿体（CLP）和二氧化钛纳米颗粒（TiO NPs）的混合半人工光合作用系统。利用TiO/CLP复合物对2,6-二氯酚靛酚（DCPIP）的还原以及TiO对亚甲基蓝（MB）的还原，来测定该混合系统中光生电子转移的增强情况。TiO/CLP复合物对DCPIP的还原与TiO对MB的还原随TiO NPs浓度变化呈现相同趋势，表明CLP截留了TiO中的光生电子，从而提高了光合作用效率。与纯TiO相比，TiO/CLP复合物的光致发光强度降低且激发态寿命缩短，这也支持了电子从TiO转移至CLP。更长的可见光吸收波长和升高的价带边缘表明TiO/CLP的带隙变窄，最终导致从TiO到CLP的电子转移增强。TiO/CLP复合物具有更高的铁氰化物还原能力和增强的ATP形成，证明了电子传递链的电子转移速率加快。本研究揭示了通过构建半人工光合作用系统，TiO与CLP相互作用以增强光合作用的机制。
