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

Abstract

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.

Revealing drug release and diffusion behavior in skin interstitial fluid by surface-enhanced Raman scattering microneedles

“…In the future, the analytes can be extended to a variety of SERS-inactive drugs by the development of more sensitive SERS MNs (such as silver NP-based MNs) or indirect SERS sensing mechanisms. 43,44…”

Recent Advances in Molecularly Imprinted Polymers for Antibiotic Analysis

“…to form the host-guest complex; addition of a crosslinker and initiation through certain initiation methods (e.g., initiator, thermal initiation, photoinitiation, etc.) to produce a highly cross-linked polymer; the template molecules are removed through appropriate means to obtain MIPs with the conformationally predetermined and specific recognition of the template molecules [17][18][19][20]. MIPs have been widely used in sample pre-treatment, chromatographic separations, sensors, etc.…”

3 nm-Wide WO3–x Nanorods with Abundant Oxygen Vacancies as Substrates for High-Sensitivity SERS Detection

“…Surface-enhanced Raman scattering (SERS) has emerged as a powerful signal enhancement technique; the Raman signals of molecules can increase by orders of magnitude when they are adsorbed onto noble metals and some semiconductors . During recent decades, SERS has attracted growing interest in chemical sensing, biological research, and catalysis monitoring. − It is generally accepted that the mechanism of SERS is composed of electromagnetic (EM) enhancement and chemical enhancement (CM). , The EM factor ρ ( r m , ω) can be expressed as the quotient of the total electric field at the molecule position E ( r m , ω) and the electric field associated with the incident plane wave E inc (ω), ρ ( r m , ω ) = true| bold-italicE ( r m , ω ) E normali normaln normalc 0.25em ( ω ) true| 4 where r m is the location of the molecule and ω is the light frequency. The EM factor severely relies on the excitation of the localized surface plasmon resonance (LSPR) effect of noble metal substrates such as Au and Ag.…”