Fork-shaped paper SERS sensors coated with raspberry-like bimetallic nanospheres for the detection of the boosted mixture: experimental design and applications

Abstract

The integration of SERS-active enhanced agents with the functional supporting substrate of paper to expand the application of SERS technology has attracted much attention. However, it is still highly desired to improve the detection ability of paper-based SERS substrates for complex mixtures to extend the application of SERS further in real-word scenarios. Herein, we assemble raspberry-like bimetallic Au@AgNP nanostructures with multiple hotspots on an arrow-shaped paper strip to detect complex samples sensitively. Raspberry-like bimetallic nanoparticles show more sensitive and stable SERS performance than spherical AgNPs, which improves the practicability of SERS-based paper substrates in realistic situations. The intervention of charge gradients as well as designing of arrow-shaped non-interference tips yields the substrate-integrated shunt and preconcentration abilities for mixture samples. Thus, this SERS-based paper substrate may provide a promising way for the determination of complex samples in food security and environmental protection. Our work will have a positive impact in pushing forward the application process of SERS technology in real-word scenarios.