Functionalised Diamond Based SERS Industrial Sensing System for Harsh Environment and High Pressure Systems

A ruggedised and integration ready surface enhanced Raman spectroscopy system has been developed for metrology in harsh environments and in industrial systems. The sealing technology has been proven to hold pressure at elevated temperature and pressure of 175 Bar and 200 °C. The diamond window features a gold nanoparticle functionalised surface to create plasmonic enhancement at the diamond/target environment interface. A fibre coupled Raman laser back-illuminates the diamond window, so that environment isolation is maintained by the diamond boundary. The system is designed for integration with pressurised water reactors (PWR) and has applications in a variety of industrial systems and fields, leveraging the outstanding optical properties and chemical and physical resilience of diamond. FEA simulation was used to inform the nanoparticle material and size. SERS substrates were fabricated by dewetting evaporated gold by thermal processing. The nanoparticles are overgrown with a thin layer of polycrystalline diamond to protect them from the target environment.