PDMS-Based SERS Substrate of High Sensitivity and Uniformity and Its Application in In Situ Detection of Tricyclazole

Abstract

In this paper, flexible and transparent surface-enhanced Raman scattering (SERS) substrate was prepared. First, silver nanoparticles (Ag NPs) were adsorbed onto 2D stretched polydimethylsiloxane (PDMS) and then the stretch was released and nanowrinkles were formed, bringing the adsorbed Ag NPs close to each other. SERS measurement demonstrated really high sensitivity of the Ag/PDMS substrate fabricated under 30% deformation and 120 min assembling time, the enhancement factor (EF) of which was estimated to be [Formula: see text]. SERS mapping analysis revealed the proposed Ag/PDMS substrate possessed excellent uniformity with relative standard deviation (RSD) of as low as 5.62%. For real-life applications, the versatile Ag/PDMS substrate could be used for both solution detection and in situ detection of solid objects of any shape. Tricyclazole, a commonly used pesticide, might pollute the leaves of crop and even remain in milk, endangering human health. Therefore, there is practical demand for developing direct on-site detection methods. In this paper, tricyclazole of 10[Formula: see text] M was easily probed by dropping the contaminated milk solution on the proposed substrate and 10[Formula: see text][Formula: see text]M tricyclazole sprayed on a leaf exhibited clearly identifiable Raman signals after attaching the proposed substrate to the leaf surface, demonstrating the prepared high-sensitive Ag/PDMS substrate is a competitive tool for rapid, trace and in situ detection.