Ag/TiO2 nanocomposites as a novel SERS substrate for construction of sensitive biosensor

In this work, the Ag/TiO2 nanocomposites was fabricated by catalytic hairpin assembly (CHA) strategy to construct surface-enhanced Raman scattering (SERS) biosensor for sensitive detection of uracil DNA glycolase (UDG), which could achieve greater Raman enhancement of methylene blue by the surface plasmon resonance (SPR) of Ag nanocubes (Ag NCs) and the charge transfer (CT) effect of TiO2 compared with traditional noble metal material. Impressively, the Pb2+ assisted DNAzyme cleavage reaction was introduced to convert the trace target UDG into great number of trigger DNA for improving the sensitivity of this method. Thus, the SERS biosensor demonstrated excellent performance for sensitive detection of UDG with a low detection limit of 1.2 ? 10-5 U mL-1. This proposed assay offered a new strategy to design SERS substrate for analysis of biomolecule and disease diagnosis.

Automated summary

The Ag/TiO2 nanocomposites were prepared via catalytic hairpin assembly (CHA) strategy to fabricate a SERS biosensor for sensitive detection of UDG, with the introduction of Pb2+ assisted DNAzyme cleavage reaction enhancing the sensitivity of the method, achieving a detection limit of 1.2×10-5 U mL-1.