Yasukuni Ryohei, Félidj Nordin, Boubekeur-Lecaque Leïla, Lau-Truong Stéphanie, Aubard Jean
Université de Paris, ITODYS, CNRS, UMR 7086, 15 rue J-A de Baïf, 75013, Paris, France.
Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, 8916-5, Japan.
Chemphyschem. 2020 Nov 17;21(22):2614-2619. doi: 10.1002/cphc.202000613. Epub 2020 Oct 30.
Localized surface plasmon resonance (LSPR) excitation on the photochromic reaction of a diarylethene derivative (DE) was studied by surface enhanced Raman scattering (SERS). UV and visible light irradiations transform reversibly DE between open-form (OF) and closed-form (CF) isomers, respectively. A mixture of PMMA and DE (either OF or CF isomer) was spin-coated onto gold nanorods (GNRs) arrays, designed by electron beam lithography, with two localized surface plasmon resonances (LSPR) at distinct wavelengths, due to their anisotropy. The photochromic reaction rates from CF to OF isomers, under LSPR excitation, were monitored from SERS spectral changes under different polarizations, on the same GNR substrate to compare the effect of LSPR field strength. It appears that the photoisomerization rate was faster when LSPR was excited with the polarization parallel to the GNR long axis. The present results highlight a potential genuine mechanism, from near field LSPR excitation, involved in the photochromic enhancement of diarylethene photochromes.
通过表面增强拉曼散射（SERS）研究了二芳基乙烯衍生物（DE）光致变色反应中的局域表面等离子体共振（LSPR）激发。紫外光和可见光照射分别使DE在开环形式（OF）和闭环形式（CF）异构体之间可逆转化。将聚甲基丙烯酸甲酯（PMMA）与DE（OF或CF异构体）的混合物旋涂到通过电子束光刻设计的金纳米棒（GNR）阵列上，由于其各向异性，该阵列在不同波长处具有两个局域表面等离子体共振（LSPR）。在LSPR激发下，通过同一GNR基底上不同偏振下的SERS光谱变化监测从CF到OF异构体的光致变色反应速率，以比较LSPR场强的影响。结果表明，当LSPR以平行于GNR长轴的偏振激发时，光异构化速率更快。目前的结果突出了一种潜在的真实机制，即近场LSPR激发参与了二芳基乙烯光致变色材料的光致变色增强过程。
