Amorphous/Crystalline Urchin‐Like TiO2 SERS Platform for Selective Recognition and Efficient Identification of Glutathione

Abstract

Glutathione serves as a common biomarkers in tumor diagnosis and treatment. The levels of its intracellular concentration permit detailed investigation of the tumor microenvironment. However, low polarization and weak Raman scattering cross‐section make direct and indirect Raman detection challenging. This study designs an amorphous‐crystalline urchin‐like TiO2 (AC‐UL‐TiO2) for the accurate identification of GSH and GSSG. By synergistically regulating the crystalline core and amorphous shell, the bandgap structure is optimized, thereby enhancing charge transfer efficiency. AC‐UL‐TiO2 demonstrates excellent SERS performance in detecting dye molecules with good selectivity for mixed analytes. The enhancement factor (EF) for R6G is 6.89 × 106, and the limit of detection (LOD) is 10−10 M. A SERS‐colorimetric dual‐modality platform is developed based on the AC‐UL‐TiO2@DTNB system to accurately monitor GSH concentrations from 0 to 1000 µM, providing a robust dual‐confirmation result. Importantly, combined with the principal component analysis method, the AC‐UL‐TiO2 SERS platform can directly distinguish GSH and GSSG molecules. Besides, direct SERS detection LOD for GSH and GSSG are 10−8 M, which is 100 times higher than that of indirect detection. These findings indicate that AC‐UL‐TiO2 holds potential for biomarkers trace detection in tumor microenvironments.