21st-century innovations in surface-enhanced raman scattering (SERS): A review of patents

In 1930, the Indian physicist Chandrasekhara Venkata Raman won the Nobel Prize of Physics for his work in understanding the light-matter interaction, known as Raman scattering. After this discovery, the advancement of the Raman spectroscopy technique has increased during the years. In this context, seeking the amplification of the Raman spectroscopy signal, the use of nanoparticles to promote the Surface-enhanced Raman scattering (SERS) effect appeared as an excellent alternative. Thus, the development of different SERS substrates with various nanostructures has been constantly happening by research groups around the world. Substrate modifications, nanoparticles with complex structures, new analysis configurations and different devices setups have gone beyond scientific publications and several researchers and companies have sought intellectual protection for their productions. In this sense, patents related to SERS, in general applications, have been filed over the years. This article brings a systematic review of patents involving the SERS effect (substrates, devices, and preparation methods) in the twenty-first century showing the main patenting trends for those who want to understand the evolution of SERS patents, as well as showing the future perspectives, thus bringing a fundamental vision for researchers in this area. For this purpose, a search was carried out in the Espacenet database, which offers access to over 150 million patent documents. The search strategy involved advanced queries for "Surface-enhanced Raman scattering" or "SERS" in patents published from January 1, 2001, to June 1, 2024, resulting in 3,436 patent documents. The findings reveal a significant increase in SERS patent publications over the years. Furthermore, it is demonstrated that universities and research institutes are the primary contributors, responsible for 70.20% of SERS patent applications. When evaluating the location of the patent application, the USA, Japan, and South Korea stand out as the three countries that fill out the most patent applications. For this reason, Asia and America emerge as the continents that most produce this type of patent with 43.41 and 42.96%, respectively. Thus, this review article gives an overview of the progress of the SERS patents in twenty-first century.