Flexible Plasmonic Biosensors for Healthcare Monitoring: Progress and Prospects

The noble metal nanoparticle has been widely utilized as a plasmonic unit to enhance biosensor, by leveraging its electric and/or optical properties. Integrated with the ‘flexible’ feature, it further enables opportunities in developing healthcare products in a conformal and adaptive fashion, such as wrist pulse tracer, body temperature tracker, blood glucose monitor, etc. In this work, we present a holistic review of the recent advance of flexible plasmonic biosensors for the healthcare sector. The technical spectrum broadly covers the design and selection of flexible substrate, the process to integrate flexible and plasmonic units, the exploration of different type of flexible plasmonic biosensors to monitor human temperature, blood glucose, ions, gas, motion indicators, as well as their applications for Surface-enhanced Raman scattering (SERS) and colorimetric detections. Their fundamental working principles and structural innovations are scoped and summarised. The challenges and prospects are articulated regarding the critical importance for continued progress of flexible plasmonic biosensors to improve living quality.