Highly Efficient Light Helicity Detection of Enantiomers by Chiral Metal–Organic Framework Thin Films

• Published in: Nano letters 2023-06, Vol.23 (12), p.5794-5801
• Main Authors: Tian, Yi-Bo, Tanaka, Koichi, Chang, Li-Mei, Wöll, Christof, Gu, Zhi-Gang, Zhang, Jian
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.3c01717

The potential of chiral metal–organic frameworks (MOFs) for circularly polarized (CP) optics has been largely unexplored. Herein, we have successfully deposited monolithic and highly oriented chiral MOF thin films prepared by a layer-by-layer method (referred to as surface-coordinated MOF thin films, SURMOF) to fabricate CP photodetection devices and distinguish enantiomers. The helicity-sensitive absorption induced by a pair of enantiopure oriented SURMOF was found to be excellent, with an anisotropy factor reaching 0.41. Moreover, the chiral SURMOFs exhibited a pronounced difference in the uptake of the l- and d-tryptophan enantiomers. To demonstrate the potential of these novel MOF thin films for chirality analysis, we fabricated a portable sensor device that allows for chiral recognition by monitoring the photocurrent signals. Our findings not only introduce a new concept of using chiral building blocks for realizing direct CP photodetectors but also provide a blueprint for novel devices in chiral optics.