Biomimetically Inspired Micro-Nano Hierarchical Structures of Rose Petals for Efficient SERS Sensing Applications

Abstract

Surface-enhanced Raman spectroscopy (SERS) detection is a crucial technology for rapid sensing and “fingerprinting”, achieved through the combination of Raman spectroscopy and arrays of noble metal nanoparticles (NPs). This study introduces a low-cost biomimetic-inspired approach to fabricate rose petal structured micro/nano hierarchical structures with silver (Ag) film, serving as a reliable SERS substrate. These substrates are thoroughly compared by replicating the upper surface of rose petals of different colors into a transparent polydimethylsiloxane (PDMS) mixture and subsequently sputtering Ag film of varying thicknesses. Ultimately, the white negative rose PDMS replica is chosen, demonstrating a high enhancement factor, good batch-to-batch reproducibility, high stability, and high sensitivity for crystal violet (CV), an organic contaminant with mutagenic and toxigenic properties. In a proof-of-concept experiment, the multiplex detection capability of this SERS substrate is demonstrated by analyzing a combination of two sets of analytes (CV and methylene blue as well as CV and Nile blue A). Furthermore, this SERS substrate is utilized to test tau protein and amyloid β peptides, both recognized biomarkers of Alzheimer's disease. This study illustrates that the proposed 3D SERS substrate exhibits significant potential for the highly sensitive and rapid detection of biomolecules in practical applications.