Abstract: A flexible wipe paper for rapid nondestructive detection of ferbam residues on the surface of fruits and vegetables by surface-enhanced Raman scattering (SERS) was prepared using filter paper as the substate by a simple soaking method. The synthesis and storage conditions were optimized to ensure that the SERS method has excellent performance. The results showed that concentration factor of silver nanoparticles (AgNPs), soaking time in AgNP solution and drying method greatly affected the performance of the SERS wipe paper. The performance under the condition of soaking for 8 h in a 5-fold concentrate of AgNP solution was significantly better than that under other conditions. The SERS wipe paper prepared by vacuum drying had better performance that those prepared by other drying methods. After 9 days of storage at −20 ℃, the optimized substrate retained approximately 50% of the original peak value. Besides, it exhibited good sensitivity, uniformity, and repeatability. The limit of detection (LOD) for ferbam on a glass plate was 4.07 × 10-6 mg/mL, and the LOD for ferbam on the surface of spinach and nectarine were 0.043 and 0.062 mg/kg, respectively. This study provides an excellent basis for the development and utilization of SERS wipe paper.

Key words: flexible substrate; surface-enhanced Raman scattering; pesticide residue; ferbam