Optical switch combined Raman spectroscopy for rapid SERS measurements

Abstract

With epidemics that have frequently occurred in the 21st century, various diagnostic techniques are being actively researched to replace the public diagnosis tool, DNA amplification technique (Poly-chain reaction, PCR). Among antigen readout techniques, SERS (Surface Enhanced Raman spectroscopy), which can find out the structure of a single molecule level, has received considerable attention as an alternative technique for replacing PCR because this can detect strong signals even with low concentration samples – inducing rapid diagnosis. Despite this advantage, it is still challenging to utilize as a public diagnostic tool due to the inconvenience of continuously replacing samples for measuring a large number of samples. In this study, we developed a SERS-based massive testing system that combined an optical switch and Raman spectroscopy, with simplifying the system to improve portability. In the system, 1xN optical switch, the mechanical displacement of input fiber is moved in a bidirectional way, which makes the input fiber shift into the location corresponding to each output fiber – inducing transmission for the light source and Raman signal. Thus, Raman data of testing samples would be automatically collectible without manual labor like changing specimens for testing another specimen, result ing in rapid diagnostic results for massive samples. We demonstrated the validation of our system by measuring Raman signals for SERS tags.