Gold nanoparticle-loaded TiO2 nanorod arrays: a 3D SERS substrate for enzyme-free glucose detection.

Abstract

A novel surface-enhanced Raman scattering (SERS) substrate, gold nanoparticle-loaded titanium dioxide nanorods (TiO₂@Au NRs), is introduced and its successful application in glucose detection demonstrated. The unique three-dimensional columnar structure of TiO₂@Au NRs, coupled with the synergistic effects of localized surface plasmon resonance, charge transfer, and Mie resonance, significantly enhances the Raman signal intensity of target molecules. This substrate exhibits remarkable stability, maintaining consistent performance for at least 70 days. Functionalization with p-mercaptophenylboronic acid enables selective capture and detection of glucose, providing a stable, non-enzymatic detection method that eliminates enzyme-related instability. This approach achieves a detection limit of 76 µM with a broad linear range of 100 µM-50 mM, effectively covering both physiological and pathological blood glucose levels. Validation with blood samples confirms high accuracy, with most errors remaining within 2%. These results demonstrate the excellent SERS performance of TiO₂@Au NRs and their potential for reliable, non-enzymatic glucose monitoring in diabetes management.