Using the nanoimprint-in-metal method to prepare corrugated metal structures for plasmonic biosensors through both surface plasmon resonance and index-matching effects

► Metallic corrugated structure is prepared as highly sensitive plasmonic sensors. ► It can sense both surface plasmon resonance wavelength and index-matching effect. ► A high sensitivity of 800 nm/RIU is achieved according to resonance wavelength shift. ► Besides, the linear response of resonance intensity is adopted for sensing as well. ► In the last, the structure demonstrates the ability to be a sensitive biosensor.