Paper-based sandwich type SERS sensor based on silver nanoparticles and biomimetic recognizer

Abstract A paper-based surface enhanced Raman scattering (SERS) sensor with synergistic enhancement strategy for selective detection of tartrazine in food products has been established in this work. For economic and mass production purposes, paper substrates were firstly installed with a silver layer to endow the paper with electroconductibility and dense plasmonic hotspots. A biomimetic recognizer (BR) membrane was attached upon the Ag paper as specific identification device, and a layer of high-density of silver nanoparticles (AgNPs) was decorated on the surface of Ag/BR paper through in-situ growth method to form a sandwich structure. Since the double layer of Ag/AgNPs demonstrated excellent local plasma resonance effect, combined with the identification function of BR, it made the paper SERS sensor emerge incredible Raman synergistic enhancement response on tartrazine molecules embraced the plasma nanoparticles. Thus, the synergistically enhanced Ag/BR/AgNPs paper SERS sensor was achieved and applied in on-site test of tartrazine in Children's snacks. The linear range (0.3∼10 μg mL−1) and the limit of detection (0.1138 μg mL−1) of the SERS paper strip could be applied as a screening or occupational cut-off of tartrazine (100 μg mL−1) for reference. In addition, the proposed paper sensor can be a potential candidate for multicomponent screening and is suitable for mass production and promotion.