AgNPs-modified IOPC-based flexible SERS patch for rapid label-free analysis of pesticide residues

Rapid analysis of pesticide residues is essential for food safety, and the efficient extraction pesticide molecules from the irregular surfaces remains huge challenges. In the present study, a proof-of-concept flexible surface-enhanced Raman scattering (SERS) patch for rapid label-free detections of thiabendazole (TBZ), triazophos (TAP), and chlorpyrifos (CPF) on the surfaces of vegetables and fruits was developed. The novel SERS patch was supported by a flexible polymethylsiloxane (PDMS), and a microhole array was arranged on the surface of the PDMS. Colloidal silver nanoparticles (AgNPs)-modified inverse opal photonic crystal (IOPC) structure was fabricated in the microhole. The patch simultaneously exhibited the characteristics of high sensitivity analysis, “sticky” and “absorbent” properties, which enabled it possible to extract pesticide molecules on complex surfaces quickly and efficiently by “press and peeled-off” procedure. The results indicate that the extraction efficiency was 55.13 ± 8.85 % on the apple surface, and the detection limits of TBZ, TAP, and CPF were 24.15, 37.56, and 4.21 ng cm −2 , respectively. Conceivably, the as-proposed strategy may also be applied to environmental monitoring and quality control in food production to ensure human life and health.