Bioinspired surface-enhanced Raman scattering substrate with intrinsic Raman signal for the interactive SERS detection of pesticides residues.

Although biomimetic surface enhanced Raman scattering (SERS) substrate which makes use of naturally existing raw materials have been fully utilized, it remains challenging to achieve credible quantitative detection. Herein, nanoimprint technology was exploited to engineer internal standard (IS) enabled quantitative flexible biomimetic SERS substrates, in which polydimethylsiloxane (PDMS) with intrinsic Raman signal was utilized as a tool to reversely duplicate surface structures from different agriculture products and then deposited with Ag nanoparticles. The resultant four kinds of biomimetic SERS substrates with different surface geometries all permit highly sensitive assay with enhancement factors (EFs) of about 10 in both drop-dry and in situ SERS detection modes. Moreover, the quantitative degree in the SERS detection was effectively corrected based on the IS strategy. Finally, an ingenious interactive in situ SERS detection was conducted. Interestingly, the maximum recovery rate was achieved when the template food was used as target surface compared with other foods, indicating the significance of manufacturing the highly conformed SERS-active structure from the surface to be tested. The proposed quantitative biomimetic SERS substrate is expected to be widely used in the field of biochemical supervision.