Label-Free SERS Fingerprinting for Chiral Discrimination Using Chiral Two-Dimensional Superlattice
Aumber Abbas, Qian Zhang, Jamal Kazmi, Ying Li, Wenbo Li, Waqas Ahmad, Chao Zou, Qijie Liang
Abstract
Chiral discrimination is crucial in chiral synthesis, pharmaceuticals, and biology. Although surface-enhanced Raman scattering (SERS) provides highly sensitive molecule-specific vibrational data, existing approaches depend on indirect detection involving supplementary selectors, impeding clear and versatile chiral discrimination. Here, we report the direct label-free SERS sensing of different biologically prominent enantiomers with a two-dimensional transition metal dichalcogenide, such as TaS 2, based chiral superlattice to produce enantiospecific molecular fingerprints. The clear enantiodiscrimination between a model chiral pair of l - and d -glucose is achieved with a detection limit of 8 × 10 –10 M. In addition, noninvasive identification of l - and d -glucose in actual saliva samples and multiplex quantification of enantiomeric ratios with superior predictive accuracy are accomplished.