SERS and dark-field scattering dual-mode detection of intracellular hydrogen peroxide using biocompatible Au@COF nanosensor

Hydrogen peroxide is widely involved in intracellular physiological activities, playing vital roles in regulating various intracellular metabolite and physiological events. Surface enhanced Raman spectroscopy (SERS) may serve as a promising technique to efficiently sensing metabolites in living cells owing to its non-invasiveness, low autofluorescence, and rapid detection capability. Herein, a size-controllable core-shell structure was constructed by covering 2D covalent organic frameworks (COFs) on Au nanoparticles (Au@COF), and the cellular hydrogen peroxide were detected by Raman spectroscopy/Dark-field scattering imaging dual-mode technique. The introduction of COFs endows Au@COF with perfect enrichment capacity as well as high stability and good biocompatibility. Combining the superior fingerprint identification of SERS and the imaging capability of dark-field microscopy, the present method exhibits high applicability for hydrogen peroxide detection in living cells. Results show that when the living MCF-7 cells were treated by different drugs, the level of H 2 O 2 metabolite can be monitored in real-time. This study provides a simple but sensitive and facile platform for biosensing hydrogen peroxide and cellular metabolites. • A biocompatible core-shell structure was constructed by covering ultrathin 2D covalent organic frameworks (COFs) on Au nanoparticles (Au@COF). • Intracellular Hydrogen Peroxide was successfully detected by Au@COF using SERS and Dark-Field Scattering Dual-Mode technique. • This study provides a simple and sensitive platform for biosensing hydrogen peroxide and cellular metabolites.