High-sensitivity detection of thiram by collaborative enhancement of surface-enhanced Raman scattering substrates...

Distinct from conventional MXene-supported Ag SERS substrates, Ti₃C₂T_x-supported four-concave-faced hollow silver nanocubes (FCFH AgNCs) integrating concave surfaces and internal cavities were developed for thiram detection. Silver nanocubes were synthesized by the polyol method and transformed through HAuCl₄-mediated etching into a series of nanostructures, including six-concave-faced AgNCs, FCFH AgNCs, and AgNC frameworks. Among them, FCFH AgNCs showed the strongest SERS activity, indicating that hollow-concave structure was most favorable for hotspot generation. After assembly with Ti₃C₂T_x via electrostatic interaction, the resulting Ti₃C₂T_x-FCFH AgNCs substrate exhibited enhanced Raman performance with an enhancement factor of 3.75 × 10⁶ and improved signal uniformity by reducing the coffee-ring effect. The optimized substrate enabled thiram detection over 1 × 10^-10 to 1 × 10^-4 mol/L, with a detection limit of 0.3 × 10^-10 mol/L, and showed good reproducibility, stability, and anti-interference ability, providing an effective strategy for pesticide residue detection and food safety monitoring and analysis.