Chiral Plasmonic Sensors: Fundamentals and Emerging Applications

Chiral plasmonic sensors have emerged as powerful tools for the enantioselective detection of biomolecules, addressing key limitations of conventional techniques such as circular dichroism (CD), chromatography, and nuclear magnetic resonance (NMR). In this review, we introduce a unifying framework based on physical and chemical chiral imprinting strategies to design nanostructures with tailored chiroptical activity. We explore the fabrication of both discrete and assembled plasmonic architectures through methods including top-down lithography, DNA-guided assembly, soft templates, and chiral molecule-directed growth. These platforms have enabled highly sensitive chiral sensing via localized surface plasmon resonance (LSPR)-based CD, colorimetry, surface-enhanced Raman scattering (SERS), photoluminescence (PL), and circularly polarized luminescence (CPL). We describe the underlying sensing mechanisms, detection limits, and the influence of nanostructure geometry and composition on chiral signal generation. Recent applications in biosensing, disease diagnostics, and asymmetric catalysis monitoring are also highlighted. Finally, we discuss current challenges and future directions for integrating chiral plasmonic sensors into practical analytical systems, offering a comprehensive overview of their conceptual foundations, fabrication strategies (with emphasis on chiral imprinting), and application landscape.