Controllable assembly of high sticky and flexibility surface-enhanced Raman scattering substrate for on-site target pesticide residues detection

Pesticide residues in fruit and vegetable constitute a great threat to mankind's health, and a technique of rapid, cost-effective, ultra-sensitive and non-destructive analysis is especially critical for on-site detection in practical application. A strategy was utilized to fabricate highly viscous and flexible WPU@AgNPs sticky tape for the rapid extraction and Surface-enhanced Raman Scattering (SERS) assay of thiabendazole residues on the surface of fruits. Simply put, the novel WPU@AgNPs tapes were constructed by decorating the waterborne polyurethane (WPU) film with silver nanoparticles (AgNPs), and demonstrated excellent sensitivity with 4-Mercaptopyridine (4-Mpy) as the probe molecule. Meanwhile, the enhancement factor of the novel SERS substrate could reach 7.01 × 10⁶, which was consistent with the finite difference time domain (FDTD) theoretical simulation results. What's more, the high viscosity and flexibility of WPU@AgNPs sticky tapes allowed them to detect the thiabendazole residues on the pear, apple and banana surfaces by a straightforward "paste and peel off" approach. The results showed that the detection limit could reach 1.44, 1.12 and 1.63 ng/cm². This strategy would be as a common method for prompt, on-site and ultra-sensitive assay of thiabendazole residues in chemical and biological fields.