CuO Quantum Dots@amorphous CoOOH Semiconductor Heterostructure for Label‐Free Surface‐Enhanced Raman Scattering Detection and Accurate Classification of Gastrointestinal Tumor Cells

Accurate discrimination of gastric cancer cells (HGC‐27) and pancreatic cancer cells (QGP‐1) from normal white blood cells (WBCs) is crucial for early screening of gastrointestinal tumors. However, traditional methods suffer from low sensitivity and reliance on external labels, failing to achieve label‐free, rapid, and single‐cell identification. Surface‐enhanced Raman scattering (SERS) offers a powerful alternative for cancer cell identification due to its high sensitivity to molecular fingerprints. Herein, CuO quantum dots@amorphous CoOOH (CuO QDs@a‐CoOOH) heterostructures were fabricated through photoelectric reconstruction from Cu 2 O@Co(OH) precursors, serving as an efficient SERS platform for tumor cell detection. During reconstruction, the Cu 2 O core is fragmented and oxidized into CuO QDs, while the outer Co(OH) 2 shell is converted into a‐CoOOH, forming CuO QDs@a‐CoOOH hollow nanocages. The synergistic effects of energy‐level coupling, charge transfer, and enhanced molecular adsorption collectively endow CuO QDs@a‐CoOOH with outstanding SERS activity. The label‐free SERS detection and accurate differentiation of HGC‐27, QGP‐1, and WBCs were achieved based on CuO QDs@a‐CoOOH. The recognition accuracies for three cell lines were 99.0%, 94.3%, and 96.3% via the principal component analysis‐linear discriminant analysis (PCA‐LDA). This high‐performance heterostructure serves as a promising SERS substrate, providing a novel strategy for label‐free and precise identification of gastrointestinal tumor cells.