Photoinduced Chirality Switching of Metal-Inorganic Plasmonic Nanostructures.
Photoinduced Chirality Switching of Metal-Inorganic Plasmonic Nanostructures.
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DOI：
10.1021/acsnano.9b10216
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发表时间：
2020-03
期刊：
影响因子：
17.1
通讯作者：
Kazeto Morisawa;T. Ishida;T. Tatsuma
中科院分区：
文献类型：
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作者：
Kazeto Morisawa;T. Ishida;T. Tatsuma
手性等离子体纳米器件由于其手性可以在外部刺激下可逆地在左、右之间切换而引起了广泛的关注。然而，它们需要精细的DNA纳米结构和/或持续的外部刺激。在本研究中，利用金属-无机纳米结构和光诱导的可逆氧化还原反应解决了这些问题，即在圆偏振可见光（CPL）下等离子体诱导电荷分离（PICS）引起的位点选择性氧化和紫外线诱导TiO2光催化还原。我们用右或左cpl照射负载在TiO2上的金纳米棒（AuNR），在每个纳米棒周围产生具有手性分布的电场，并在电场定位的位置沉积PbO2，以固定纳米棒的手性。由此制备的纳米结构表现出基于aunr的纵向和横向等离子体模式的圆二色性（CD）。它们的手性被右cpl（或左cpl）锁定，直到PbO2在紫外光下被重新还原。紫外解锁后，手性可以通过左cpl（或右cpl）照射来切换，导致CD信号反转并再次锁定开关。手性等离子体纳米器件的手性可以可逆地反复切换。
Chiral plasmonic nanodevices whose handedness can be switched reversibly between right and left by external stimulation have attracted much attention. However, they require delicate DNA nanostructures and/or continuous external stimulation. In this study, those issues are addressed by using metal-inorganic nanostructures and photoinduced reversible redox reactions at the nanostructures, namely site-selective oxidation due to plasmon-induced charge separation (PICS) under circularly polarized visible light (CPL) and reduction by UV-induced TiO2 photocatalysis. We irradiate gold nanorods (AuNRs) supported on TiO2 with right- or left-CPL to generate electric fields with chiral distribution around each AuNR, and to deposit PbO2 at the sites where the electric fields are localized, for fixing the chirality to the AuNR. The nanostructures thus prepared exhibit circular dichroism (CD) based on longitudinal and transverse plasmon modes of the AuNRs. Their chirality given by right-CPL (or left-CPL) is locked until PbO2 is re-reduced under UV light. After unlocking by UV, the chirality can be switched by left-CPL (or right-CPL) irradiation, resulting in reversed CD signals and locking the switch again. The handedness of the chiral plasmonic nanodevice can be switched reversibly and repeatedly.