Etching‐Based Chiroplasmonic Sensing with Helicoid Au Nanocrystals for Anti‐Interference Biochemical Detection

Abstract Plasmonic nanomaterials with intrinsic chiral morphology represent a profound and intriguing topic in sensing applications due to their ultrasensitive chiral structure‐dependent chiroptical activity. Here, an H 2 O 2 ‐assisted etching strategy is reported, enabling the tunable chiroptical activity of chiral helicoid Au nanocrystals by varying size and morphology. This approach forms the foundation of a chiroplasmonic sensing method leveraging the chiroptical signal response induced by morphological changes. Notably, the method exhibits excellent anti‐interference performance, enabling reliable detection in complex and colored sample environments. Moreover, the strategy is extended for glucose detection through glucose oxidase‐catalyzed H 2 O 2 production, with quantitative detection in real colored samples confirming its reliability. The chiroplasmonic sensing based on helicoid Au nanocrystal etching exhibits remarkable detection performance in complex environments, offering the potential for practical applications in biochemical analysis and diagnostics.