Surface Plasmon Coupled Directional Emission for Integrated Fluorescence‐Raman Biodetection: A Proof‐of‐Concept Study

Abstract The development of multi‐functional nanoplatforms has attracted much attention. The realization of fluorescence and Raman dual‐mode bio‐detection typically needs complicated switching procedures or algorithm processes. In this work, we propose that a surface plasmon coupled emission (SPCE) technique could be used to break the bottleneck. Our approach enabled Raman spectra which would normally suffer interfered by strong fluorescence signal to be distinguished, simply by respective measurements at different angles. As a proof of concept, we prepared dual‐mode nano‐composites for measurement. Herein, in SPCE, fluorescence was sharply distributed at 46° and Raman at 50°. Attributed to the unique directional radiation feature, collection efficiency increased dramatically, with nearly 5‐fold and 14‐fold absolute intensity enhancement compared to conventional fluorescence and Raman method. Meanwhile, Raman detectability could be improved dramatically in SPCE detection in contrast to free space measurement in one single wavelength excitation device, for serious fluorescence interference to Raman tags could be eliminated.