Photocurrent of a single photosynthetic protein
Photocurrent of a single photosynthetic protein
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DOI：
10.1038/nnano.2012.165
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发表时间：
2012-10-01
影响因子：
38.3
通讯作者：
Carmeli, Itai
中科院分区：
文献类型：
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作者：
Gerster, Daniel;Reichert, Joachim;Carmeli, Itai
植物、藻类和细菌利用光合作用将太阳能转化为稳定的化学能。这个过程的最初阶段——光被吸收，能量和电子被转移——是由叶绿素和类胡萝卜素复合物组成的反应中心介导的(1)。以前的研究表明，单个小分子可以用作电气（2-6）和光电子电路（7-10）的功能组件，但在光伏（11-13）和光电化学应用（14-16）中，很难控制和探测单个分子。在这里，我们展示了由单一光合蛋白-光系统i产生的光电流可以使用扫描近场光学显微镜装置进行测量。蛋白质的一侧固定在充当电极的金表面上，另一侧则由镀金的玻璃尖端接触。尖端既可作为反电极又可作为光源。从共价结合的单蛋白连接处记录到约10 pA的光电流，这与光系统I的内部电子传递时间一致。
Photosynthesis is used by plants, algae and bacteria to convert solar energy into stable chemical energy. The initial stages of this process-where light is absorbed and energy and electrons are transferred-are mediated by reaction centres composed of chlorophyll and carotenoid complexes(1). It has been previously shown that single small molecules can be used as functional components in electric(2-6) and optoelectronic circuits(7-10), but it has proved difficult to control and probe individual molecules for photovoltaic(11-13) and photoelectrochemical applications(14-16). Here, we show that the photocurrent generated by a single photosynthetic protein-photosystem I-can be measured using a scanning near-field optical microscope set-up. One side of the protein is anchored to a gold surface that acts as an electrode, and the other is contacted by a gold-covered glass tip. The tip functions as both counter electrode and light source. A photocurrent of similar to 10 pA is recorded from the covalently bound single-protein junctions, which is in agreement with the internal electron transfer times of photosystem I.