A plasmonic Ag nanoparticle decorated ZnO array on-chip sensor was developed for label-free detection of opioids through surface-enhanced Raman spectroscopy. The sensor reliably detects opioids as low as 90 ng mL−1 in human blood serum with great accuracy and sensitivity.
In recent years, significant progress has been made into the label-free detection and discrimination of individual cancer cells using Laser Tweezers Raman Spectroscopy (LTRS).