Chiral molecular imprinting-based SERS detection strategy for absolute enantiomeric discrimination

• Published in: Nature communications 2022-09, Vol.13 (1), p.5757-5757, Article 5757
• Main Authors: Arabi, Maryam, Ostovan, Abbas, Wang, Yunqing, Mei, Rongchao, Fu, Longwen, Li, Jinhua, Wang, Xiaoyan, Chen, Lingxin
• Format: Article
• Language: English
• Subjects: 13/1; 14/28; 140/133; 49/47; 639/301/1005/1009; 639/638/11/511; 9/10; 96/95; Binding; Cavities; Chirality; Enantiomers; Functional groups; Humanities and Social Sciences; Molecular imprinting; multidisciplinary; Permeability; Raman spectra; Science; Science (multidisciplinary); Seawater
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-33448-w

Chiral discrimination is critical in environmental and life sciences. However, an ideal chiral discrimination strategy has not yet been developed because of the inevitable nonspecific binding entity of wrong enantiomers or insufficient intrinsic optical activities of chiral molecules. Here, we propose an “inspector” recognition mechanism (IRM), which is implemented on a chiral imprinted polydopamine (PDA) layer coated on surface-enhanced Raman scattering (SERS) tag layer. The IRM works based on the permeability change of the imprinted PDA after the chiral recognition and scrutiny of the permeability by an inspector molecule. Good enantiomer can specifically recognize and fully fill the chiral imprinted cavities, whereas the wrong cannot. Then a linear shape aminothiol molecule, as an inspector of the recognition status is introduced, which can only percolate through the vacant and nonspecifically occupied cavities, inducing the SERS signal to decrease. Accordingly, chirality information exclusively stems from good enantiomer specific binding, while nonspecific recognition of wrong enantiomer is curbed. The IRM benefits from sensitivity and versatility, enabling absolute discrimination of a wide variety of chiral molecules regardless of size, functional groups, polarities, optical activities, Raman scattering, and the number of chiral centers. Absolute chiral discrimination in chiral imprinted systems is complicated by the nonspecific binding of enantiomers. Here, the authors report a SERS “inspector” recognition mechanism to distinguish between specifically and nonspecifically bound enantiomers, even in seawater and urine.